BIO FINAL Critique Essay
Unlock all answers in this set
Unlock answersquestion
What properties or processes do we associate with ALL living things
answer
evolutionary adaptations, energy processing, responding to the environment, and growth and reproduction
question
Which of the following sequences represents the hierarchy of biological organization from the LEAST to the MOST complex level? A. molecule, cell, organ system, population, ecosystem, biosphere B. cell, community, population, organ system, molecule, organelle C. organism, community, biosphere, molecule, tissue, organ D. ecosystem, cell, population, tissue, organism, organ system E. organelle, tissue, biosphere, ecosystem, population, organism
answer
A. Molecule, cell, organ system, population, ecosystem, biosphere
question
In terms of the hierarchical organization of life, a bacterium is at the _______ level of organization whereas a human is at the ______ level of organization
answer
single-celled organism; multicellular organism
question
For most ecosystems ______ is/are the ultimate source of energy, and energy leaves the ecosystem in the form of ________.
answer
sunlight; heat
question
The lowest level of biological organization that can perform all the activities required for life is what?
answer
cell-for example, a skin cell
question
Which branch of biology is concerned with the naming and classifying of organisms?
answer
taxonomy
question
Species that are in the same ________ are more closely related than species that are only in the same _____.
answer
family; order
question
What is the hierarchical organization of life from MOST to LEAST inclusive?
answer
kingdom, phylum, class, order, family, genus, species
question
What provides evidence of the common ancestry of all life?
answer
the universality of the genetic code
question
What is true of natural selection?
answer
It requires genetic variation, results in descent with modification, and involoves differential reproductive success
question
Why is it important that an experiment include a control group?
answer
Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor
question
What is true about ecology?
answer
Ecologists may study populations and communities of organisms. Ecological studies may involve the use of models and computers. Ecology spans increasingly comprehensive levels of organization, from individuals to ecosystems. Ecology is the study of the interactions between biotic and abiotic aspects of the environment.
question
Ecology as a discipline directly deals with which levels of biological organization?
answer
population, organismal, ecosystem, community
question
Landscape ecology is the study of what?
answer
the factors controlling the exchange of energy, materials, and organisms among ecosystem patches
question
What biotic factors can affect the structure and organization of biological communities?
answer
predation, competition
question
What abiotic factor has the greatest influence on the metabolic rates of animals?
answer
temperature
question
Coral reefs can be found on the southern east coast of the US but not at similar latitudes on the southern west coast. Differences in what can account for this?
answer
ocean currents
question
Turnover of water in temperature lakes during the spring and fall is made possible because...?
answer
The density of water changes as seasonal temperatures change
question
Generally speaking, deserts are located in places where air masses are usually...?
answer
descending
question
The success with which plants extend their range northward following glacial retreat is best determined by what?
answer
their seed dispersal rate
question
What organism is the MOST likely candidate for geographic isolation?
answer
land snail
question
Where would an ecologist find the most phytoplankton in a lake?
answer
photic zone
question
Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of what?
answer
convergent evolution
question
The growing season would be shortest in what biome?
answer
coniferous forest
question
A population is CORRECTLY defined as having what characteristics?
answer
Inhabiting the same general area and individuals belonging to the same species
question
An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square mile in one woodlot and 20 per square mile on another woodlot. What was the ecologist comparing?
answer
density
question
You are observing a population of lizards when you notice that the number of adults has suddenly increased and is higher than previously observed. One explanation for such an observation would include..?
answer
increased immigration
question
Researchers in the Netherlands studied the effects of parental caregiving in European kestrels over 5 years. The researchers transferred chicks among nests to produce reduced broods (three or four chicks), normal broods (five or six), and enlarged broods (seven or eight). They then measured the percentage of male and female parent birds that survived the following winter and reported the data in the accompanying figure. (Both males and females provide care for chicks.) What is a conclusion that can be drawn from this data?
answer
there appears to be a negative correlation between brood enlargements and parental survival
question
What most directly contributes to density-dependent regulation of populations?
answer
intraspecific competition for nutrients
question
Field observation suggests that populations of a particular species of herbivorous mammal undergo ciclic fluctuations in density at three-to five-year intervals. What is a plausible explanation of these cycles?
answer
Periodic crowding affects the endocrine system, resulting in increased aggressiveness; increases in population density lead to increased rates of predation; increases in rates of herbivory lead to changes in the nutritive value of plants used as food; increases in population density lead to more proximal infestations of parasites to host animals
question
What is a density-independent factor limiting human population growth?
answer
earthquakes
question
A population of white-footed mice becomes severely overpopulated in a habitat that has been disturbed by human activity. Sometimes intrinsic factors cause the population to increase in mortality and lower reproduction rates in reaction to the stress of overpopulation. What is an example of population control?
answer
Females undergo hormonal changes that delay sexual maturation and many individuals suffer depressed immune systems die due to the stress of overpopulations
question
Which of the following statements is consistent with the principle of competitive exclusion? A. Bird species generally do not compete for nesting sites. B. The density of one competing species will have a positive impact on the population growth of the other competing species C. Two species with the same fundamental niche will exclude other competing species D. Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species E. Evolution tends to increase competition between related species
answer
D. Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species
question
The sum total of an organism's interaction with the biotic and abiotic resources of its environmental it is called its...?
answer
ecological niche
question
Use the diagram of Joseph Connell's study of barnacle distribution in Scotland to answer the following question. What is the most logical conclusion about the distribution of the two species of barnacle, Chthamalus and Balanus?
answer
Balanus is less able to resist desiccation than Chthamalus
question
What is resource partitioning?
answer
slight variations in niche allow similar specie to coexist
question
What is an example of cryptic coloration?
answer
a \"walking stick\" insect that resembles a twig
question
What is an example of Batesian mimicry?
answer
a non-venomous snake that looks like a venomous snake
question
What is an example of aposematic coloration?
answer
stripes of a skunk
question
Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients and water from the vascular tissues of the trees. The trees derive no known benefits from the dwarf mistletoes but may be harmed. What is the interaction between dwarf mistletoes and trees?
answer
parasitism
question
Evidence shows that some grasses benefit from being grazed. What term describes this plant-herbivore interaction?
answer
mutualism
question
What is an example of an ecological community?
answer
The interactions of all the plant and animal species inhabiting a 2 hectare section of forest
question
Community ecologists would consider what to be most significant in understanding structure of an ecological community?
answer
determining how many species are present overall, which particular species are present, the kinds of interactions that occur among organisms of different species, and the relative abundance of species
question
What have been used by plants to avoid being eaten?
answer
possessing spines and thorns on stems and leaves; synthesis of chemical toxins, such as strychnine, nicotine, and tannins; producing chemicals that are distasteful to herbivores, such as cinnamon, clove, and peppermint; and synthesizing chemicals that can cause abnormal development in some insects that eat them.
question
The species richness of a community refers to what?
answer
number of different species
question
In a tide pool, 15 species of invertebrates were reduced to eight after one species was removed. The species removed was likely what?
answer
a keystone species
question
You are most likely to observe primary succession in a terrestrial community when you visit where?
answer
a recently created volcanic island
question
Which of the following terms encompasses all of the others? A. heterotrophs B. herbivores C. carnivores D. primary consumers E. secondary consumes
answer
A. heterotrophs
question
What is an example of an ecosystem?
answer
Interactions between all of the organisms and their physical environment in a tropical rain forest
question
Suppose you are studying the nitrogen cycling in a pond ecosystem over the course of a year. As you are collecting data, a flock of 100 Canada geese lands and spends the night during a fall migration could you do to eliminate error in your study as a result of this event?
answer
Find out how much nitrogen is consumed and eliminated by a Canada goose over about a 12-hour period and multiply this number by 100; enter this +/- value into the nitrogen budget of the ecosystem
question
How is it that the open ocean results in the highest net primary productivity of Earth's ecosystem primary productivity per square meter is relatively low?
answer
oceans have the greatest total area
question
Aquatic ecosystems are least likely to be limited by what nutrient?
answer
carbon
question
If you wanted to convert excess grain into the greatest amount of animal biomass, to which animal would you feed the grain?
answer
mealworms (larval insects)
question
A secondary consumer, such as a fox, receives what percent of the energy fixed by primary producers in a typical field ecosystem?
answer
1%
question
Nitrogen is available to plants mainly in the form of what?
answer
nitrate ions in the soil
question
Which of the following statements is CORRECT about biogeochemical cycling? A. The phosphorus cycle involves the recycling of atmospheric phosphorus B. The phosphorus cycle is a cycle that involves the weathering of rocks C. The carbon cycle is a localized cycle that primarily involves the burning of fossil fuels D. The carbon cycle has maintained a constant atmospheric concentration of CO2 for the past several million years E. The nitrogen cycle involves movement of diatomic nitrogen between the different abiotic components of the ecosystem
answer
B. The phosphorus cycle is a cycle that involves the weathering of rocks
question
Why are biologists currently concerned with climate change and the thawing of permafrost in many areas of the tundra biome?
answer
The bacterial decomposition of the thawed organic materials on the widespread areas of the tundra will produce large quantities of CO2, which will add to greenhouse gases and exacerbate climate change.
question
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter?
answer
Carbon, hydrogen, nitrogen, oxygen
question
Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. What directly indicates the number of protons in an atom's nucleus?
answer
atomic number
question
Different atomic forms of an element contain the same number of protons but a different number of neutrons. What are these different atomic forms called?
answer
isotopes
question
How many electrons does nitrogen have in its valence shell?
answer
5
question
A covalent chemical bond is one in which...?
answer
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms
question
Nitrogen (N) is much more electronegative than hydrogen (H). What is true about the atoms in ammonia (NH3)?
answer
Each hydrogen atom has a partial positive charge
question
The ionic bond of sodium chloride is formed when...?
answer
Chlorine gains an electron from sodium
question
What most specifically explains the attraction of water molecules to one another?
answer
A hydrogen bond
question
Van der Waals interactions result when...?
answer
electrons are not symmetrically distributed in a molecule
question
Sometimes atoms form molecules by sharing two pairs of valence electrons. When this occurs, the atoms are said to be joined by what?
answer
a double covalent bond
question
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by what?
answer
polar covalent bonds
question
The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?
answer
a hydrogen bond
question
What can occur because of the high surface tension of water?
answer
a water strider can walk across the surface of a small pond
question
Water's high specific heat is mainly a consequence of what?
answer
the absorption and release of heat when hydrogen bonds break and form
question
What type of bond must be broken for water to vaporize?
answer
hydrogen bonds
question
Hydrophobic substances such as vegetable oil are...?
answer
nonpolar substances that repel water molecules
question
What is the pH of a solution with a hydrogen ion [H+] concentration of 10^-8M?
answer
pH 8
question
Which of the following solutions has the greatest concentration of hydrogen ions? A. household bleach at pH 12 B. tomato juice at pH 4 C. black coffee at pH 5 D. gastric juice at pH 2 E. vinegar at pH 3
answer
D. gastric juice at pH 2
question
What is true of buffer solutions?
answer
they maintain a relatively constant pH when either acids or bases are added to them
question
Research indicates that acid precipitation can damage living organisms by...?
answer
washing away certain mineral ions that both help buffer soil solutions and that are essential nutrients for plant growth
question
Carbon dioxide is readily soluble in water according to the equation CO2+H2O-->H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells release CO2. What prediction can we make about the pH of blood as that blood first comes in contact with respiring cells?
answer
blood pH will decrease slightly
question
Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?
answer
the absorption of heat by the breaking of hydrogen bonds
question
Early 19th-century scientists believed that living organisms differed from nonliving things as a result of possessing a \"life force\" that could create organic molecules from inorganic matter. The term given to this belief is....?
answer
vitalism
question
Who used this apparatus to study the formation of organic compounds?
answer
Stanley Miller
question
Why are hydrocarbons insoluble in water?
answer
the majority of their bonds are non polar covalent carbon-to-caron or carbon-to-hydrogen linkages
question
Shown here are the structures of glucose and fructose. These two molecules are (quiz 4 #4)
answer
structural isomers
question
The two molecules shown are best described as (quiz 4 #5)
answer
geometric isomers
question
Research indicates that Albuterol, a drug used to relax bronchial musles, improving airflow and thus offering relief from asthma, consists only of one enantiomer, the R-form. Why is it important for this drug to consist of only one enantiomeric form, rather than a mixture of enantiomers?
answer
Different enantiomers may have different or opposite physiological effects
question
A compound contains hydroxyl groups as its predominant functional group. What is true concerning this compound?
answer
It should dissolve in water
question
What is the best description of a carbonyl group?
answer
a carbon atom joined to an oxygen by a double covalent bond
question
What is the name of the functional group shown (quiz 4 #9)
answer
carboxyl
question
Which two functional groups are ALWAYS found in amino acids?
answer
carboxyl and amino
question
Which molecule contains a sulfhydryl functional group? (quiz 4 #11)
answer
B
question
Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way do these molecules differ from each other?
answer
testosterone and estradiol have different functional groups attached to the same carbon skeleton
question
Which of the following is NOT a polymer? A. glucose B. starch C. cellulose D. chitin E. DNA
answer
glucose
question
What is the chemical mechanism by which cells make polymers from monomers?
answer
dehydration reactions
question
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together buy dehydration reactions?
answer
C18H32O16
question
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
answer
as a disaccharide
question
What is true about saturated fats?
answer
they are more common in animals than in plants, they generally solidify at room temperature, they contain more hydrogen then unsaturated fatty acids having the same number of carbon atoms, they are hydrophobic
question
What is true for the class of biological molecules known as lipids?
answer
they are an important constituent of cell membranes, they can store more energy than proteins and carbohydrates, they are not true polymers, this group includes waxes and steroids
question
What is a triglyceride?
answer
a lipid made with three fatty acids and glycerol
question
What is true regarding the molecule illustrated in this figure? (quiz 4 # 21)
answer
molecules of this type are usually liquid at room temperature
question
The molecule shown in this figure is...? (quiz 4 # 22)
answer
an unsaturated fatty acid
question
What is the structure shown in this figure? (quiz 4 # 23)
answer
a steroid molecule (lipid)
question
The bonding of two amino acid molecules to form a larger molecule requires...?
answer
the release of a water molecule
question
Which of the following statements is TRUE regarding the chemical reaction illustrated in this figure? (quiz 4 #25)
answer
it results in a peptide bond
question
What is a major component in maintaining the secondary structure of a protein?
answer
hydrogen bonds
question
The tertiary structure of a protein is the...?
answer
unique tree-dimensional shape of a fully folded polypeptide
question
why is it important to know what microscopy method was used to prepare the images you wish to study?
answer
so that you can make a judgement about the likelihood of artifacts having been introduced in the preparation
question
Which of the following contains its own DNA and ribosomes? A. lysosome B. vacuole C. mitochondrion D. Golgi apparatus E. peroxisome
answer
mitochondrion
question
Grana, thylakoids, and stroma are all components found in...?
answer
chloroplasts
question
organelles other than the nucleus that contain DNA include...?
answer
chloroplasts and mitochondria
question
The chemical reactions involved in respiration are virtually identical between prokaryotic and eukaryotic cells. In eukaryoti cells, ATP is synthesized primarily on the inner membrane of the mitochondria. Where are the corresponding reactions likely to occur in prokaryotic respiration?
answer
on the inner plasma membrane
question
What organelle is capable of converting light energy to chemical energy?
answer
Chloroplasts
question
Cells can be described as having a cytoskeleton of internal structures that contribute to the shape, organization, and movement of the cell. What is part of the cytoskeleton?
answer
microfilaments
question
The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall apart, what would you expect to be the most likely consequence?
answer
a change in the shape of the nucleus
question
Under what conditions would you expect to find a cell with a majority of \"free\" ribosomes (not connected to the rER)?
answer
a cell that is producing cytoplasmic enzymes
question
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
answer
smooth endoplasmic reticulum
question
The Golgi apparatus has a polarity or sidedness to the structure and function. What describes this polarity?
answer
transport vesicles fuse with one side of the Golgi and leave from the opposite side, proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other, lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other, soluble proteins in the cistern (interior) of the Golgi may be sorted and modified as they move from one side of the Golgi to the other
question
In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular compounds. Which organelle functions in this compartmentalization?
answer
lysosome
question
Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition?
answer
the lysosome
question
The liver is involved in detoxification of many poisons and drugs. What structure is primarily involved in this process and therefore abundant in liver cells?
answer
smooth ER
question
What contains enzymes that transfer hydrogen from various substrates to oxygen?
answer
peroxisome
question
Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?
answer
cytoskeletons
question
What types of molecules are the major structural components of the cell membrane?
answer
phospholipids and proteins
question
The presence of cholesterol in the plasma membranes of some animals...
answer
enables the membrane to stay fluid more easily when cell temperature drops
question
According to the fluid mosaic model of cell membranes what is true of membrane phospholipids?
answer
the can move laterally along the plane of the membrane
question
What is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold?
answer
by increasing the percentage of unsaturated phospholipids in the membrane
question
In order for a protein to be an integral membrane protein it would have to be what?
answer
amphipathic
question
What is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures?
answer
the double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart
question
What is not embedded in the lipid bilayer at all?
answer
peripheral proteins
question
What kinds of molecules pass through a cell membrane most easily?
answer
small and hydrophobic
question
What is a characteristic feature of a carrier protein in a plasma membrane?
answer
It exhibits a specificity for a particular type of molecule
question
What is true of diffusion?
answer
It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration
question
Cystic fibrosis is a genetic disease in humans in which chloride ion channels in cell membranes are missing or nonfunctional. What would you expect to be a problem for someone with nonfunctional chloride channels
answer
a buildup of excessive ions in various types of cells
question
The solutions in the two arms of the U-tube shown below (quiz 5 #22) are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half filled with a solution of 2M sucrose and 1M glucose. Side B is half filled with 1M sucrose and 2M glucose. Initially, the levels on both sides are equal. After the system reaches equilibrium, what changes are observed?
answer
The water level is higher in side A than in side B
question
A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is transferred directly into one of her veins. What will be the most probable result of this transfusion?
answer
the patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells
question
Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are...?
answer
hypertonic to fresh water but hypotonic to the salt solution
question
A cell whose cytoplasm has a concentration of .02 molar glucose is placed in a test tube of water containing .02 molar glucose. Assuming that glucose is not actively transported into the cell, what term describes the tonicity of the external solution relative to hte cytoplasm of the cell?
answer
isotonic
question
When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur?
answer
the cell will become turgid
question
What membrane activity requires energy from ATP hydrolysis?
answer
NA+ ions moving out of the cell
question
Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, what transport mechanism is most probably functioning in the intestinal cells?
answer
facilitated diffusion
question
What is the voltage across a membrane called?
answer
membrane potential
question
The sodium-potassium pump is called an electrogenic pump because it...?
answer
contributes to the membrane potential
question
Ions diffuse across membranes down their...?
answer
electrochemical gradients
question
Proton pumps are used in various ways by members of every Domain of organisms. What is the likely explanation for this?
answer
Cells with proton pumps were maintained in each domain by natural selection
question
An organism with a cell wall would have the most difficulty doing what process?
answer
phagocytosis
question
In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis?
answer
on the inside surface of the vesicle
question
What is the term that describes the process of breaking down large biological molecules into smaller ones?
answer
catabolism
question
What is true of anabolic pathways?
answer
they consume energy to build up polymers from monomers
question
What is the first law of thermodynamics?
answer
energy cannot be created or destroyed
question
For living organisms what is an important consequence of the first law of thermodynamics?
answer
the organism ultimately must obtain all of the necessary energy for life from its environment
question
Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?
answer
as a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth
question
What is an example of potential rather than kinetic energy?
answer
a food molecule made up of energy-rich covalent bonds
question
What is true for all exergonic reactions?
answer
the reaction proceeds with a net release of free energy
question
A chemical reaction that has a positive delta G is described as a...?
answer
endergonic
question
Why is ATP an important molecule in metabolism?
answer
it provides energy coupling between exergonic and endergonic reactions
question
What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways?
answer
energy coupling
question
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?
answer
it is lost to the environment
question
What is true of enzyme-catalyzed reactions?
answer
the reaction occurs faster than the same reaction in the absence of the enzyme
question
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's...?
answer
activation energy
question
The breakdown of starch is usually a spontaneous reaction. However a solution of starch at room temperature does not readily decompose to form a solution of simple sugars because...?
answer
the activation energy barrier for this reaction cannot be surmounted
question
Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. What is the purpose of using malonic acid in this experiment?
answer
it is a competitive inhibitor
question
How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?
answer
by changing the shape of the enzyme's active site
question
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is a what?
answer
feedback inhibition
question
What are the products made during the light reactions of photosynthesis that are utilized in the Calvin cycle?
answer
ATP and NADPH
question
Where in a eukaryote does the Calvin cycle take place?
answer
stroma of the chloroplast
question
In any ecosystem. terrestrial or aquatic, what group is the basis of all biological communities?
answer
autotrophs
question
In autotrophic bacteria, where are the enzymes located that can carry on organic synthesis?
answer
along the inner surface of the plasma membrane
question
What is the relationship between wavelength of light and the quantity of energy per photon?
answer
they are inversely related
question
What is the primary function of the Calvin cycle?
answer
synthesize simple sugars from carbon dioxide
question
How are the light reactions and Calvin cycle of photosynthesis connected?
answer
the light reactions provide ATP and NADPH to the Calvin cycle, and the Calvin cycle sends back ADP and NADP+
question
Some photosynthetic bacteria (e.g., purple sulfur bacteria) have Photosystem I but not II, while others (e.g., cyanobacteria) have both PSI and PSII. What does this observation imply?
answer
Photosystem I must be more ancestral
question
Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants?
answer
they dissipate excessive light energy
question
What is the relationship between the light reactions and the Calvin cycle?
answer
the light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions
question
Where do the enzymatic reactions of the Calvin cycle take place?
answer
stroma of the chloroplast
question
What is the primary function of the Calvin cycle?
answer
synthesize simple sugars from carbon dioxide
question
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Which, neither, or both the Calvin cycle and light reactions produces molecular oxygen (O2)?
answer
light reactions alone
question
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Which, neither, or both the Calvin cycle and light reactions produces NADH?
answer
neither the light reactions nor the Calvin cycle
question
In the process of carbon fixation RuBP attaches a CO2 molecule to produce a 6 carbon molecule, which is then split in 2. After phosphorylation and reduction, what more needs to happen in the Calvin cycle?
answer
regeneration of RuBP
question
The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytoplasm of a particular plant cell. Which, if any, relationship would you expect to find?
answer
the pH within the thylakoid is likely less than that of the stroma or the cytoplasm
question
Glyceraldehyde-3-phosphate (G3P) is produced in the stroma of chloroplasts. What is true of G3P?
answer
it is the sugar produced by the Calvin cycle
question
What is the term for metabolic pathways that release stored energy by breaking down complex molecules?
answer
catabolic pathways
question
The molecule that functions as the reducing agent (electron donor) in a redox or reduction-oxidation reaction...
answer
loses electrons and loses energy
question
Where does glycolysis take place?
answer
cytosol
question
The ATP made during glycolysis is generated by...
answer
substrate-level phosphorylation
question
What process in eukaryotic cells will proceed normally whether oxygen is present or absent?
answer
glycolysis
question
substrate-level phosphorylation accounts for approximately what percentage of the ATP formed during glycolysis?
answer
100%
question
During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is...
answer
retained in the pyruvate
question
What kind of metabolic poison would most directly interfere with glycolysis?
answer
an agent that closely mimics the structure of glucose but is not metabolized
question
What metabolic pathway is common to both cellular respiration and fermentation?
answer
glycolysis
question
The ATP made during fermentation is generated by what?
answer
substrate-level phosyphorylation
question
In alcohol fermentation, NAD+ is regenerated from NADH during what?
answer
reduction of acetaldegyde to ethanol (ethyl alcohol)
question
One function of both alcohol fermentation and lactic acid fermentation is to...
answer
oxidize NADH to NAD+
question
Why is glycolysis considered to be one of the first metabolic pathways to have evolved?
answer
it is found in the cytosol, does not involve oxygen, and is present in most organisms
question
When muscle cells are oxygen deprived, the heart still pumps. What must the heart cells be able to do?
answer
continue aerobic metabolism when skeletal muscle cannot
question
During cellular respiration in a eukaryotic cell, acetyl CoA accumulates in which location?
answer
mitochondrial matrix
question
For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced?
answer
12
question
Cellular respiration harvests the most chemical energy from what?
answer
chemiosmotic (oxidative) phosphorylation
question
The primary role of oxygen in cellular respiration is to...?
answer
act as an acceptor for electrons and hydrogen, forming water
question
The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is...
answer
the difference in H+ concentrations on opposite sides of the inner mitochondrial membrane
question
Assume a mitochondrion contains 58 NADH and 19 FADH2. If each of the 77 dinucleotides were used, approximately how many ATP molecules could be generated as a result of oxidative phosphorylation (chemiosmosis)?
answer
212
question
What metabolic pathway is common to both cellular respiration and fermentation?
answer
glycolysis
question
The ATP made during fermentation is generated by what?
answer
substrate-level phosphorylation
question
Why is glycolysis considered to be one of the first metabolic pathways to have evolved?
answer
it is found in the cytosol, does not involve oxygen, and is present in most organisms
question
What is a chromatid?
answer
a replicated chromosome that is still attached
question
What term describes centrioles beginning to move apart in animal cells?
answer
prophase
question
What term describes centromeres uncoupling, sister chromatids separating, and the two new chromosomes moving to opposite poles of the cell?
answer
anaphase
question
If there are 20 chromatids in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis
answer
10
question
Cytokinesis usually, but not always, follows mitosis. If a cell completed mitosis but not cytokinesis, the result would be a cell with...?
answer
2 nuclei
question
Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants...
answer
a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage
question
During which phases of the cell cycle and mitosis are chromosomes composed of 2 chromatids?
answer
from G2 of interphase through metaphase
question
The somatic cells derived from a single-celled zygote divided by what process?
answer
mitosis
question
Several organisms, primarily Protists, have what are called intermediate mitotic organization. These Protists are intermediate in what sense?
answer
they maintain a nuclear envelope during division
question
What triggers the cell's passage past the G2 checkpoint into mitosis?
answer
MPF
question
The MPF protein complex turns itself off by...
answer
activating a process that destroys the cyclin component
question
Asexual reproduction and sexual reproduction differ how?
answer
individuals reproducing asexually transmit 100% of their genes to their progeny, whereas individuals reproducing sexually transmit only 50%; asexual reproduction produces offspring that are genetically identical to the parents, whereas sexual reproduction gives rise to genetically distinct offspring; asexual reproduction requires only mitosis, whereas sexual reproduction always involves meiosis; asexual reproduction involves a single parent, whereas sexual reproduction involves two
question
Asexual reproduction results in identical offspring unless what occurs?
answer
mutation
question
What is a karyotype?
answer
a display of every pair of homologous chromosomes within a cell, organized according to size and shape
question
What is true of a species that has a chromosome number of 2n=16?
answer
each cell has 8 pairs of homologous chromosomes
question
In animals, meiosis results in gametes, and fertilization results in...?
answer
zygotes
question
If an organism is diploid and a certain gene found in the organism has 18 known alleles (variants), then any given organism of that species can/must have what?
answer
at most, 2 alleles for that gene
question
After telophase I of MEIOSIS, the chromosomal makeup of each daughter cell is..
answer
haploid, and the chromosomes are each composed of 2 chromatids
question
How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis?
answer
they have half the number of chromosomes and one-fourth the amount of DNA
question
For the following question, match the key event of meiosis with the stages listed below: I. Prophase II. Metaphase III. Anaphase IV. Telophase VI. Prophase II VII. Anaphase II VIII. Telophase II Centromeres of sister chromatids and chromatids separate
answer
VII. Anaphase II
question
Homologous chromosomes synapse and crossing over occurs (Mitosis, Meiosis I, Meiosis II, all of them, some of them, none of them)
answer
the statement is true for Meiosis I only
question
Put in order: 1. Formation of 4 new nuclei, each with half the chromosomes present in the parental nucleus 2. Alignment of homologous chromosomes at the metaphase plate 3. Separation of sister chromatids 4. Separation of the homologous chromosomes without separation of the chromatids 5. Synapsis; chromosomes moving to the middle of the cell in pairs
answer
5,2,4,3,1
question
A tetrad include what sets of DNA strands?
answer
2 sets of sister chromatids that have synapsed
question
A certain organism is diploid, has either blue or orange wings as the consequence of one of its genes, and has either long or short antennae as the result of a second gene. If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, she will produce what egg types? (quiz 9 # 8)
answer
1/2 blue and 1/2 orange gene eggs
question
How does the sexual life cycle increase the genetic variation in a species?
answer
by allowing independent assortment of chromosomes
question
Independent assortment of chromosomes is a result of...?
answer
the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I
question
Pea plants were particularly well suited for the use in Mendel's breeding experiments because?
answer
peas show easily observed variations in a number of characters such as pea shape and flower color; it is possible to control matings between different pea plants; it is possible to obtain large numbers of progeny from any given cross; many of the observable characters that vary in pea plants are controlled by single genes
question
What is the difference between a monohybrid cross and a dihybrid cross?
answer
a dihybrid cross involves organisms that are heterozygous for two characters and a monohybrid only one
question
The F1 offspring of Mendel's classic pea cross always looked like one of the 2 parental varieties because
answer
one phenotype was completely dominant over another
question
How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?
answer
8
question
Two plants are crosse, resulting in offspring with a 3:1 ratio for a particular trait. This suggests...
answer
that the parents were both heterozygous
question
Two traits that appear in a 9:3:3:1 ratio in the F2 generation should have what properties?
answer
the genes controlling the traits obey the law of independent assortment
question
A sexually reproducing animal has 2 unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. What genotype is possible in a gamete from this organism if it were produced by a NORMAL meiosis?
answer
HT
question
It was important that Mendel examined not just the F1 generation in his breeding experiments, but the F2 generation as well, because...?
answer
parental traits that were not observed in the F1 reappeared in the F2
question
The fact that all 7 of the pea plant traits studied by Mendel obeyed the principle of independent assortment most probably indicates what?
answer
all of the genes controlling the traits behaved as if they were on different chromosomes
question
Mendel's second law of independent assortment has its basis in what event of meiosis?
answer
alignment of tetrads at the equator
question
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTtxBBtt will have black fur and long tails (assume independent assortment)?
answer
1/2
question
Two true-breeding stocks of pea plants are crossed. One parent has red, axial flowers and the other has white, terminal flowers; all F1 individuals have red, axial flowers. The genes for flower color and location assort independently. If 1000 F2 offspring resulted from the cross, approximately how many of them would you expect to have red, terminal flowers?
answer
190
question
In a cross AaBbCc x AaBbCc, what is the probability of producing the genotype AABBCC?
answer
1/64
question
Labrador retrievers are black, brown, or yellow. In a cross of a black female with a brown male, results can be either all black puppies, 1/2 black to 1/2 brown puppies , or 3/4 black to 1/4 yellow puppies. How many genes must be responsible for these coat colors in labrador retrievers?
answer
2
question
Radish flowers may be red, purple, or white. The part of the radish we eat may be oval or long, with long being the dominant characteristic. A cross between a red-flowered, long radish plant and a white-flowered, oval radish plant yields all-purple, long radish offspring. In the F2 generation of the above cross, what phenotypic ratios would be expected (assume independent assortment)?
answer
6:3:3:2:1:1
question
A 1:2:1 PHENOTYPIC ratio in the F2 generation of a monohybrid cross is a sign of...
answer
incomplete dominance
question
Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. At the same time, a second gene, N, determines whether cacti have spines. Homozygous nn cacti have no spines at all. The relationship between genes S and N is an example of what?
answer
epistasis
question
What describes the ability of a single gene to have multiple phenotypic effects?
answer
pleiotropy
question
What is an example of polygenic inheritance?
answer
skin pigmentation in humans
question
Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by what?
answer
environmental factors such as soil pH
question
Huntington's disease is a dominant condition with late age of onset in humans. If only one parent has the disease (heterozygous), what is the probability that his or her child will have the disease?
answer
1/2
question
When a disease is said to have a multifactorial basis, it means what?
answer
both genetic and environmental factors contribute to the disease
question
The frequency of heterozygosity for the human sickle cell anemia allele in sub-saharan populations is unusually high, presumably because this reduces the frequency of malaria. Such a relationship is related to what?
answer
Darwin's explanation of natural selection
question
Males are more often affected by sex-linked traits than females because...
answer
males are hemizygous for the X chromosome
question
What is the chromosomal system for determining sex in mammals?
answer
X-Y
question
What is the chromosomal system of sex determination in most species of ants and bees?
answer
Haploid-diploid
question
In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell (aka calico). What kinds of offspring would you expect from the cross of a black female and an orange male?
answer
tortoiseshell females; black males
question
Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes?
answer
100%
question
In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female?
answer
2:1 male to female
question
A man who is achondroplastic with normal vision marries a color-blind woman of normal height. The man's father was six feet tall, and both the woman's parents were of average height. Achondroplasm is autosomal dominant, and red-green color blindness is X-linked recessive. How many of their daughters might be expected to be achondroplastic AND color-blind?
answer
none
question
A Barr body is normally found in the nucleus of which kind of human cell?
answer
somatic cells of an XX female only
question
New combinations of linked genes are due to what?
answer
crossing over
question
What is the reason that linked genes are inherited together?
answer
they are located close together on the same chromosome
question
If nondisjunction occurs in meiosis II during gametogenesis, what will be the result of the completion of meiosis?
answer
1/4 of the gametes will be n+1, one will be n-1, and two will be n
question
If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)?
answer
n+1; n+1; n-1; n-1
question
One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called?
answer
translocation
question
A nonreciprocal crossover causes what products?
answer
deletion and duplication
question
An inversion in a human chromosome often results in no demonstrable phenotypic effect in the individual. What else may occur?
answer
some abnormal gametes may be formed
question
In his transformation experiments, what did Griffith observe?
answer
mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form
question
After mixing a heat-killed, phosphorescent strain of bacteria with a living non-phosphorescent strain, you discover that some of the living cells are now phosphorescent. What observations would provide the best evidence that the ability to fluoresce has now become a heritable trait?
answer
descendants of the living cells are also phosphorescent
question
In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of what facts?
answer
DNA contains phosphorus, but protein does not
question
Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?
answer
12
question
Chargaff's analysis of the relative base composition of DNA was significant because he was able to show that...?
answer
the amount of A is always equivalent to T, and C to G
question
Why does the DNA double helix have a uniform diameter?
answer
purines pair with pyrimidines
question
What kind of chemical bond is found between paired bases of the DNA double helix?
answer
hydrogen bonds
question
It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in what?
answer
sequence of bases
question
Mendel and Morgan did not know about the structure of DNA; however, what contributions of theirs wet necessary to Watson and Crick?
answer
the particulate nature of the hereditary material
question
What is meant by the description \"antiparallel\" regarding the strands that make up DNA?
answer
the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand
question
Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell divides once in the presence of this radio active base?
answer
DNA in both daughter cells would be radioactive
question
An Okazaki fragment has what arrangement?
answer
5' RNA nucleotides, DNA nucleotides 3'
question
What enzyme catalyzes the synthesis of a DNA strand in the 5'---->3' direction
answer
DNA polymerase III
question
What determines the nucleotide sequence of the newly synthesized strand during DNA replication?
answer
the nucleotide sequence of the template strand
question
You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent....?
answer
leading strands and Okazaki fragments, respectively
question
What removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments?
answer
DNA polymerase I
question
What separates the DNA strands during replication?
answer
helicase
question
What covalently connects segments of DNA
answer
ligase
question
What synthesizes short segments of RNA?
answer
primase
question
The difference between ATP and the nucleotides used during DNA synthesis is that...
answer
the nucleotides have the sugar deoxyribse; ATP has the sugar ribose
question
The leading and the lagging strands observed in DNA replication differ in what ways?
answer
the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction
question
A new DNA strand elongates only in the 5' to 3' direction because...
answer
DNA polymerase can only add nucleotides to the free 3' end
question
What sets of materials are required by both eukaryotes and prokaryotes for DNA replication?
answer
double-stranded DNA, 4 kinds of dNTP, primers, origins
question
In a metabolic pathway a mutation results in a defective enzyme A. What would be the consequence of that mutation?
answer
an accumulation of A and no production of B and C
question
The genetic code is essentially the same for all organisms. From this, one can logically assume what?
answer
a gene from an organism could theoretically be expressed by any other organism; all organisms have a common ancestor; the same codons in different organisms usually translate into the same amino acids; different organisms use the same types of amino acids to make polypeptides
question
In what ways is RNA polymerase different from DNA polymerase?
answer
RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis
question
RNA polymerase moves in which direction along the DNA?
answer
3'--->5' along the template strand
question
A part of the promoter found in Archaea and Eukaryotes, called the TATA box, is said to be highly conserved in evolution. What could this indicate?
answer
any mutation in the sequence is selected against
question
What helps to stabilize eukaryotic mRNA by inhibiting its degradation?
answer
5'-cap and 3'-poly (A) tail
question
What are the coding segments of a stretch of eukaryotic DNA called?
answer
exons
question
Once transcribed, eukaryotic pre-mRNA typically undergoes substantial alteration that includes...
answer
excision of introns
question
A mutation in which part of a gene is likely to be most damaging to a cell?
answer
exon
question
Alternative RNA splicing...
answer
can allow the production of different proteins from a single mRNA
question
What is a codon?
answer
a triplet in the same reading frame as an upstream AUG
question
What is true for both prokaryotic and eukaryotic gene expression?
answer
RNA polymerase binds to the promoter region to begin transcription
question
Put in proper sequence: 1. An aminoacyl-tRNA binds to the A site 2. A peptide bond forms between the new amino acid and a polypeptide chain. 3. tRNA leaves the P site, and the P site remains vacant 4. A small ribosomal subunit binds with mRNA 5. tRNA translocates to the P site
answer
4,1,2,5,3
question
What are polyribosomes?
answer
groups of ribosomes reading a single mRNA simultaneously
question
What type of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?
answer
a deletion of 2 nucleotides
question
What is the effect of a nonsense mutation in a gene?
answer
it introduces a premature stop codon into the mRNA
question
Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of...
answer
the fossil record
question
During a study session about evolution, one of your fellow students remarks, \"The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result.\" Correct this student's misconception.
answer
characteristics acquired during an organism's life are generally not passed through genes
question
As a young biologist, Charles Darwin had expected the living plants of temperate South America would resemble those of temperate Europe, but he was surprised to find that they more closely resembled the plants of tropical South America. The biological explantation for this observation is most properly associated with the field of ...?
answer
biogeography
question
Charles Darwin was the first person to propose...?
answer
a mechanism for evolution that was supported by evidence
question
In Darwin's thinking, the more closely related 2 different organisms are, the...
answer
more recently they shared a common ancestor
question
Put in order: 1. Well-adapted individuals leave more offspring than do poorly adapted individuals 2. A change occurs in the environment 3. Genetic frequencies within the population change 4. Poorly adapted individuals have decreased survivorship
answer
2,4,1,3
question
To observe natural selection's effects on a population what must be true
answer
one must observe more than one generation of the population and the population must contain genetic variation
question
During drought years on the Galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection?
answer
more small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks
question
DDT was once considered a \"silver bullet\" that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. What would have been required for the pest eradication effort to be successful in the long run?
answer
none of the individual insects should have possessed genomes that made them resistant to DDT
question
If two modern organisms are distantly related in an evolutionary sense, then one should expect that..
answer
they should share fewer homologous structures than 2 more closely related organisms
question
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities?
answer
by identifying the bones as being homologous and by proposing that humans, bats, and dolphins share a common ancestor
question
Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?
answer
under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits
question
Members of 2 different species possess a similar-looking structure that they use in a similar fashion to perform the same function. What information would help distinguish between an explanation based on homology versus one based on convergent evolution?
answer
The 2 species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical
question
Monkeys of South and Central America have prehensile tails, meaning that their tails can be used to grasp objects. The tails of African and Asian monkeys are not prehensile. What discipline is most likely to provide an evolutionary explanation for how this difference in tails came about?
answer
biogeography
question
About what did Darwin have a poor understanding?
answer
the source of genetic variations among individuals
question
What is the smallest unit upon which natural selection directly acts?
answer
an individual's phenotype
question
What is the smallest unit that natural selection can change?
answer
a population's allele frequencies
question
In modern terminology, diversity is understod to be a result of genetic variation. Sources of variation for evolution include:
answer
mistakes in DNA replication; translocations and mistakes in meiosis; recombination at fertilization; recombination by crossing over in meiosis
question
What makes determining the evolutionary relatedness of different species based on the amino acid sequence of homologous proteins generally less accurate than determinations of relatedness based on the nucleotide sequences of homologous genes?
answer
silent mutations
question
In a Hardy-Wienberg population with 2 alleles, A and a, that are in equilibrium, the frequency of alleles is .2. What is the frequency of individuals with Aa genotype?
answer
.32
question
A large population of lab animals have been allowed to breed randomly for a number of generations. After several generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What is the estimated frequency of allele A in the gene pool?
answer
.50
question
You are studying 3 populations of birds. Population A has 10 birds, of which one is brown (a recessive trait) and 9 are red. Population B has 100 birds, of which 10 are brown. Population C has 30 birds, and 3 of them are brown. What population is MOST likely to be subject to the bottleneck effect?
answer
Population A
question
You are maintaining a small population of fruit flies in the lab by transferring the flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flies has decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to...
answer
cross your flies with flies from another lab
question
if the original finches that had been blown over to the Galapagos from South America had already been genetically different from the parental population of South American finches, even before adapting ot hte Galapagos, this would have been an example of...
answer
genetic drift and founder's effect
question
Adult male humans generally have deeper voices than do adult female humans, as the direct result of higher levels of testosterone causing growth of the larynx. If the fossil records of apes and humans alike show a trend toward decreasing larynx size in adult females, and increasing larynx size in adult males, then...
answer
sexual dimorphism was developing over time in these species
question
When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism...
answer
leaves more viable offspring than others of its species
question
If female peacocks chose brightly colored male peacocks to mate with more frequency than drab peacocks, what is occurring?
answer
sexual selection
question
Most Swiss starlings produce 4 to 5 eggs in each clutch. Those producing fewer or more than this have reduced fitness. What term describes this?
answer
stabilizing selection
question
Fossil evidence indicates that horses have gradually increased in size over geologic time. What term describes this?
answer
directional selection
question
A certain species of land snail exists as either a cream color or a solid brown color. Intermediate individuals are relatively rare. What term describes this?
answer
disruptive selection
question
Mules are relatively long-lived and hardy organisms that cannot, generally speaking, perform successful meiosis. Consequently, what is true of mules?
answer
they have a relative evolutionary fitness of zero
question
Several closely related frog species of the genus RANA are found in the forests of the southeastern United States. The species boundaries are maintained by reproductive barriers. In each case, match the various descriptions of frogs below with the appropriate reproductive barrier listed: Males of one species sing only when its predators are absent; males of another species sing only when its predators are present
answer
behavioral
question
Several closely related frog species of the genus RANA are found in the forests of the southeastern United States. The species boundaries are maintained by reproductive barriers. In each case, match the various descriptions of frogs below with the appropriate reproductive barrier listed: Males of one species are too small to perform amplexus (an action that stimulates ovulation) with females of all other species
answer
mechanical
question
Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to what reproductive isolating mechanism?
answer
habitat isolation
question
Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to completely develop and hatch. What is the mechanism for keeping these two frog species separate?
answer
the postzygotic barrier called hybrid inviability
question
Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should...
answer
strengthen postzygotic barriers between subsequent generations of horses and donkeys
question
The biological species concept is inadequate for grouping what?
answer
asexual organisms
question
Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons? I. The environment is unlikely to change II. Human evolution is complete III. There is gene flow among the races
answer
III only
question
A defining characteristic of allopatric speciation is...
answer
geographic isolation
question
The difference between geographic isolation and habitat differentiation is the...
answer
relative locations of 2 populations as speciation occurs
question
What is generally TRUE of 2 very closely related species that have diverged from each other quite recently?
answer
they shared a common ancestor recently in evolutionary time
question
You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your summer job is to separate them into species.There is no accompanying information as to where or when they were collected. Which species concept will you have to use?
answer
morphological
question
Beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers and red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it?
answer
sympatric speciation, habitat differentiation
