BCOR-012 Final Exam Part 2 - Flashcards

Q: Which sequence provides a model for describing the process of meiosis

Chromosomes replicate â¾ Homologous chromosomes separate â¾ Cytokinesis â¾ Sister chromatids separate â¾ Cytokinesis

question

In Meiosis, a _____ parent cell divides to form _____ daughter cells

answer

Diploid; 4 haploid

question

When do homologous chromosomes line up in a pairwise fashion on the equatorial plate during meiosis?

answer

During metaphase 1 only

question

Which sequence provides a model for describing the process of meiosis

answer

Chromosomes replicate ⇾ Homologous chromosomes separate ⇾ Cytokinesis ⇾ Sister chromatids separate ⇾ Cytokinesis

question

Sister chromatids present at metaphase 2 might not be genetically identical to each other because ______

answer

Of crossing over events taking place during Meiosis 1

question

Independent assortment results in gametes containing _____

answer

Many combinations of genes and parts of genes that originated from both the organism's male or female parent

question

Two genes coding for proteins involved in glycolysis reside on the same chromosome. Can these genes assort independently?

answer

Yes, with a greater chance if the genes are located far apart from one another on the chromosome

question

If cells with the genotype SsYyRr undergo meiosis, how many types of gametes will be produced? Assume that the genes are on different chromosomes.

answer

8

question

In a pedigree analysis, a shaded circle is used to represent a _____ and a partially shaded circle is used to represent an _____

answer

Fully affected female; unaffected female carrier

question

A human disease is observed to follow an autosomal dominant pattern of inheritance. If a boy diagnosed with the disease has a father who does not have the disease, what can be deduced about the boy's mother?

answer

She must be affected by the disease also

question

Tongue-rolling is a human trait that follows an autosomal recessive pattern of inheritance. A girl with the tongue-rolling trait has two brothers who do not have this trait. What is true of the children's parents?

answer

One parent must be heterozygous and the other is either heterozygous or homozygous recessive

question

A man affected by a recessive trait on the X chromosome marries a woman who neither shows the trait nor is a carrier. Which outcome is possible if they have two children-a son and a daughter?

answer

An unaffected son and a carrier daughter

question

In what way did T. H. Morgan's fruit fly data not conform to Mendel's law of independent assortment?

answer

In his F1 generation, Morgan observed more than the expected numbers of flies with parental phenotypes

question

What factor determines how often two alleles for a gene will recombine?

answer

The physical distance that separates them on the chromosome

question

The gene for body color and wing shape reside on the same chromosome in fruit flies. After crossing female flies having gray bodies and normal wings with male flies having black bodies and vestigial wings, Morgan observed that some of the F1 flies had nonparental phenotypes (gray bodies with vestigial wings, or black bodies with normal wings). What accounts for this?

answer

The alleles for wing shape and body color recombined by crossing over

question

What fraction of offspring of the cross Aa × Aa is homozygous for the dominant allele?

answer

1/4

question

What fraction of the offspring of the cross AaBb × AaBb would show the dominant phenotypes for both genes?

answer

9/16

question

Suppose unattached earlobes are a dominant trait. Phil and Maggie both have unattached earlobes but their daughter, Celia, does not. If Phil and Maggie have a second child, what is the probability that he or she will have attached earlobes?

answer

1/4

question

The cross AaBb × AaBb is an example of a _____ cross; the results of such crosses led Mendel to propose what we now call the law of _____

answer

Dihybrid; independent assortment

question

In a test cross, peas of an unknown genotype are crossed with peas of a known genotype. In this example, smooth peas are the unknown and wrinkled peas are the known (rr). If half of the offspring from that cross are smooth and half are wrinkled, what is the genotype of the unknown plant?

answer

Heterozygous: Rr

question

The 9:3:3:1 ratio is obtained _____

answer

Through a dihybrid cross in which the genes are on different chromosomes

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_____ is the term for when heterozygous offspring have superior fitness than their homozygous parents

answer

Heterosis

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Codominance

answer

Involves the expression of both alleles at a locus producing two different phenotypes

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Incomplete dominance

answer

Results in a phenotypic ratio of 1:2:1 in the F2 generation from a monohybrid cross

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A woman of blood group A has a child with a man of blood group B. The child's blood is type O. What are the genotypes of the parents?

answer

Mother: IAIO; father: IBIO

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Coat color in rabbits involves the effects of multiple gene interactions. If a rabbit has two recessive alleles (cc) for coat color, it is always albino no matter what the genotype of other genes involved in coat color. This is an example of _____

answer

Epistasis

question

The fact that a trait such as height in humans varies over a wide range of values is due to _____

answer

Multiple alles and the environmental influences on the expression of these genes

question

When a true-breeding red flower is crossed with a white flower, and all the F1 flowers are pink, this is due to _____

answer

Incomplete dominance

question

Which statement about linkage of genes is false?

answer

Genes on the same chromosome assort independently

question

True statements about linkage of genes

answer

Crossing over between two linked genes can alter phenotypes of progeny; Genes on the same chromosome are said to be linked; Genes on the same chromosome that are far apart have a higher recombination frequency than those that are close together; Crossing over results in recombinant phenotypes

question

In many animals, including humans, sex is determined by a single _____, or by a pair of them. Both males and females have two copies of each of the rest of the chromosomes, which are called _____

answer

Sex chromosome; autosomes

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In sex-linked inheritance of a recessive gene, if a normal male and a heterozygous female carrier mated, all _____

answer

Male offspring who receive the mutant X chromosome would show the trait

question

Wild-type fruit flies have red eyes. A white-eyed female fly is crossed with a red-eyed male fly. All of the females from the cross are red-eyed and all of the males are white-eyed. What type of inheritance pattern is this?

answer

Sex-linked on X chromosome

question

Genes located on mitochondrial DNA are usually inherited ______

answer

From the mother

question

Lateral gene transfer between individuals of a species _____

answer

Can result in bacterial strains resistant to antibiotics

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In order for natural selection to change a trait within a population, what must be true about the trait?

answer

The trait must have a genetic basis

question

A study showed that the mortality risk for human babies goes up as birth weight decreases below the average. Another study shows an increase in mortality risk as birth weight increases above the average. What can be said about human birth weight?

answer

It is a trait that is shaped by stabilizing selection

question

Each of the following features of a population, with the exception of one, may prevent the population from maintaining Hardy-Weinberg equilibrium. Which of the following is the exception?

answer

The population is large

question

What is the sum of frequencies of all alleles for any given gene in a population?

answer

1

question

Using the Hardy-Weinberg equations, determine the frequency of a homozygous recessive genotype (q2) if the frequency of the dominant allele is p = 0.8. Assume that there are only two types of alleles for this gene in the population.

answer

0.04

question

In explaining what we now call evolution, Darwin often used the phrase "descent with modification." Fundamental to this idea is that _____

answer

Divergent species share a common ancestor

question

Mistakes in the replication of DNA _____

answer

Provide genetic variation

question

Which phenomenon is not an evolutionary mechanism?

answer

Random mating

question

Which evolutionary process adapts populations to their environments?

answer

Natural selection

question

The frequency of one allele for a given gene locus with two alleles (A at frequency p and a at frequency q) in a population is known. Assume Hardy-Weinberg conditions hold true. Which statement is false?

answer

The frequency of heterozygotes is given by (p + q)/N, where N is the number of individuals in the population

question

The frequency of an allele in a population of manatees is 0.15. If the population is at Hardy-Weinberg for this locus, what number of 600 individuals should be homozygous for this allele?

answer

13.5

question

The Hardy-Weinberg equilibrium is not applicable under which condition?

answer

Asexual reproduction

question

The Hardy-Weinberg equilibrium is applicable under which conditions?

answer

Random mating; Infinite population size; No gene flow; No mutations

question

You discover a population of seals and find it to be at Hardy-Weinberg equilibrium with respect to the A locus. Suppose that there are two alleles at this locus and the frequency of one of those alleles (the a-6 allele) is 0.4. Of the individuals that carry at least one a-6 allele, what percent are homozygotes?

answer

25

question

Which statement about selection is true?

answer

Disruptive selection is the only type of selection that can produce a bimodal distribution

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______ selection operates if individuals within a population with the smallest and largest body sizes have fewer offspring than those of average body size

answer

Stabilizing

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Suppose the size of a population of mustard plants is 6,000. According to genetic drift theory, what is the probability that a newly-arisen mutation will become fixed in this population?

answer

1/12,000

question

Which statement about synonymous mutations is true?

answer

They do not change the phenotype

question

A neutral mutation _____

answer

Is fixed in a population at a rate equal to the mutation rate

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A gene involved in neural development shows three times as many synonymous site substitutions than nonsynonymous ones. A likely explanation is that this gene _____

answer

Is under purifying selection

question

Which observation would most seriously challenge the hypothesis that most noncoding DNA is slightly deleterious?

answer

Species with larger population sizes have more noncoding DNA

question

Which statement about he genomes of organisms is false?

answer

The total size of the genome of eukaryotes varies little from organism to organism

question

Sexual recombination ______

answer

Can result in the elimination of harmful mutations

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Gene families are groups of ______ genes that arose by _____ & _____

answer

Homologous; Gene duplication; Sequence evolution

question

Which of the following statements is true of the parsimony method for reconstructing phylogeny?

answer

The preferred phylogenetic tree under the parsimony method is the tree that requires the smallest number of evolutionary changes to explain the data

question

Which of the following types of data could be compared during the construction of a phylogenetic tree?

answer

Base sequences of the same gene from two individuals of different species

question

In the experiment described in the tutorial, why did the investigators add a mutagen to the culture medium?

answer

To increase the rate of evolutionary change in the viruses

question

Why did the investigators keep the identities of each virus generation a secret from the other researchers developing the phylogenetic tree?

answer

To be sure that only the sequence information was used in the construction of the phylogenetic tree

question

Of the following scenarios, which would provide the best analogy for describing the process of constructing a phylogenetic tree using genetic information?

answer

Assembling a jigsaw puzzle

question

A student comments that constructing phylogenetic trees must be possible for organisms with many shared characteristics such as camels and horses, but not possible for organisms with no obvious shared characteristics such as oak trees and sharks. Which statement provides the best evaluation of the student's thinking?

answer

The student's thinking is flawed because oak trees and sharks can be compared using phylogenetic analysis, since all organisms share some basic genetic characteristics

question

The _____ of a phylogenetic tree represents the common ancestor, the _____ represent events where lineages diverged, and the _____ axis represents time. Assume that the tree is oriented as described in the textbook.

answer

Root; Nodes; Horizontal

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A _____ is any group of organisms we name, while a _____ is any _____ that consists of all the evolutionary descendants of a common ancestor

answer

Taxon; Clade; Taxon

question

Which statements about traits is true?

answer

A trait may be considered ancestral or derived, depending on the point of reference; Derived traits differ from their ancestral forms; Homoplastic traits can arise by convergent evolution; Traits may be lost by evolutionary reversal

question

The bones in the wings of birds and bats are _____ because they derived from a _____ ancestor, while the wings are _____ traits

answer

Homologous; Common; Homoplastic

question

A sea squirt is thought to be more closely related to vertebrates than once thought because _____

answer

Both vertebrate embryos and sea squirt larvae have notochords

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Three character sets are being considered for inclusion in a phylogenetic analysis of lizards. The first (A) is fossil data on lizards from 10 to 20 million years ago. The second (B) is on a variety of mating behaviors that have been shown to be learned. The third (C) is from a few nuclear genes that have variable rates of evolution. Which is least likely useful to the analysis of phylogenetic relationships, and why?

answer

B, because it involves learned traits

question

The best way to assess the accuracy of methods to reconstruct phylogenetic history is to _____

answer

Use experimental tests of organisms with known evolutionary histories

question

Phylogenetic analyses of opsin pigments have allowed scientists to infer that ancestral archosaurs _____

answer

May have been nocturnal

question

Suppose that mice and humans differ by 30 substitutions in their globin genes, and rats and mice differ by five substitutions. On the basis of other evidence, we know that the ancestor to humans and mice lived 84 million years ago. Assuming the molecular clock is operating, rats and mice split from each other _____ million years ago

answer

14

question

A molecular clock assumes that the genes used _____

answer

Are evolving slowly

question

The studies of self-incompatible (outcrossing) species of Leptosiphon illustrate _____

answer

How phylogenetic systematics can reveal convergent evolution

question

In the classification system devised by Linnaeus, the names of _____ of plants end with the suffix _____, while those of animals end with _____

answer

Families; -aceae; -idae

question

Which statements about biological classification is true?

answer

Taxonomists use biological classification to show evolutionary relationships among organisms; Separate rules for classification have been established by botanists and zoologists; Classifications should be monophyletic; A monophyletic group may be removed from a phylogenetic tree with a single cut

question

A taxon that contains organisms that do not share a common ancestor is referred to as _____

answer

Polyphyletic

question

What did the simulation demonstrate about the rate at which geographically isolated subsets of a population become reproductively incompatible?

answer

The rate increases as the rate of genetic change increases in both subsets

question

What factor contributes to genetic divergence between two geographically isolated populations?

answer

The appearance of different mutations in the two populations; Natural selection; Genetic Drift

question

Which of the following is a key element of the Dobzhansky-Muller model of speciation, in which two lineages diverge from a single lineage?

answer

Incompatible alleles at different loci become fixed in the two lineages

question

What is allopatric speciation?

answer

The splitting of one species into two as a result of geographic barriers

question

Why is genetic drift often a factor influencing speciation after a founder event?

answer

Because founder events typically involve small numbers of individuals

question

A biologist has identified two groups of salamanders with very similar physical features on opposite banks of a river. Which investigative approach would help determine whether the groups are the result of allopatric speciation?

answer

Compare the gene pools of the two populations to see if there are any alleles not shared by both groups

question

A student states that genetic drift was responsible for genetic divergence of picture-winged Drosophila on the Hawaiian Islands, which led to speciation. Another student states that natural selection was responsible. Evaluate these two statements based on information presented about these flies in the tutorial

answer

Both students are correct

question

What is polyploidy?

answer

The condition of having more than the normal number of chromosomes

question

How do allopatric and sympatric speciation differ?

answer

Allopatric speciation involves a physical separation of groups as they form new species; sympatric speciation does not

question

How is an allopolyploid plant formed?

answer

Two plants of different species interbreed to form a plant of a new species

question

How would you expect the rate of speciation of an allopatric case to compare to the rate of speciation of a sympatric case involving formation of allopolyploid offspring?

answer

The allopatric case would occur at a much slower rate than the sympatric case involving allopolyploid offspring

question

Ernst Mayr's biological species concept _____

answer

Does not apply to organisms that reproduce asexually

question

Which statement about the morphological species concept is true?

answer

Linneaus used one

question

Which species concept most emphasizes the evolutionary history of species?

answer

The lineage species concept

question

The Dobzhansky-Muller model _____

answer

Emphasizes gene interaction

question

In the Dobzhansky-Muller model, an ancestral population (aabb) splits into two lineages. Different mutations produce different new alleles in each population (Aabb in one population, aaBb in the other). All of the following genotypes would be viable except _____

answer

AaBb

question

True statements about speciation

answer

Gene flow within a population must be interrupted for speciation to occur; The Dobzhansky-Muler model is based on a minimum of two gene loci; Chromosomal rearrangements can lead to speciation; Reproductive isolation may take millions of years

question

Which of the following is least likely to lead to allopatric isolation?

answer

A small lake dividing a population of butterflies

question

Geographic isolation _____

answer

Geographic barrier, genetic divergence, reproductive isolation

question

Darwin's finches on the Galápagos Islands have diverged primarily via _____ speciation, and exhibit diverse morphologies owing to differences in _____

answer

Allopatric; This diets

question

A butterfly is separating into two different groups—one that lays eggs in the understory of bushes and the other that lays eggs in the tops of bushes. This butterfly species is most likely experiencing _____

answer

Symmetric speciation

question

What statement about polyploidy in plants is true?

answer

Allopolyploids are hybrid plants that result from the mating of two closely related species

question

The distinction between pre zygotic and post zygotic isolation is whether _____

answer

The isolation occurs before or after fertilization

question

Two geographically separated populations of butterflies begin to diverge in the time of day they are active. One group is active earlier in the day, and the other is active later. If this separation were to continue, it would most likely contribute to _____ isolation

answer

Temporal

question

Pre zygotic isolating mechanisms can arise from all the following _____

answer

Evolution of the structure of sexual organs; Specific interactions of plants with insect pollinators; Mate selection behaviors; Differences in mating periods

question

Suppose that the natural ranges of horses and donkeys were to overlap. Which of the following statements best describes what would likely happen to the populations over time?

answer

Because their hybrid offspring are not reproductively fit, reinforcement could strengthen prezygotic barriers

question

Two populations that were once isolated come into contact. Which of the following statements about what might happen after contact is true?

answer

If reproductive isolation is not complete, the two populations could interbreed; Hybrids, if fit, could spread through both populations, resulting in gene flow between them; If reproductive isolation had been established before contact, the two populations could not interbreed; Hybrid zones that last for long periods of time could develop

question

Which are most likely to evolve via direct natural selection?

answer

Temporal isolation; Mechanical isolation; Behavioral isolation; Habitat isolation

question

Persistent hybrid zones, like those found in Bombina frogs in Europe, stay narrow due to _____

answer

Low hybrid adult viability

question

Where does a mosquito pick up the Plasmodium falciparum parasite?

answer

From an infected human

question

Why is a mosquito an efficient vector for transmitting Plasmodium falciparum to humans?

answer

Because mosquitoes contact human blood with their mouth parts

question

Human to human transmission of Plasmodium falciparum is not observed. Why?

answer

The infecting organism must pass through part of its life cycle in another host

question

What was the origin of all chloroplasts?

answer

A single cyanobacterium

question

Which phrase could be used in a description of secondary endosymbiosis?

answer

A eukaryote engulfing a eukaryote

question

What would a biologist look for in order to determine whether a chloroplast in a cell evolved as the result of primary endosymbiosis or secondary endosymbiosis?

answer

The number of membranes in the chloroplast

question

Based on information provided in the tutorial, which of the following pairs of organisms has the closest evolutionary relationship?

answer

Green algae and land plants

question

According to genetic evidence, two main lines of descent emerged from the last universal common ancestor. One of these lines gave rise to the _____

answer

Bacteria and Archaea

question

Why were ribosomal RNA molecules (rRNA) so important in showing the relationships between organisms in the three domains?

answer

Because rRNA is basic to all cells and its sequence reveals phylogenetic information

question

Consider the following series of strata in undisturbed sedimentary rocks: (1) Richmond is found below Talos and above Pitts; (2) Pitts is found above Somas; (3) Garett is above Talos. Based upon the principles of stratigraphy, where would you be most likely find the oldest fossils?

answer

Somas

question

The ratio of 14C to its stable isotope, (12C), is relatively constant in living organisms and their environment, however, this ratio changes once an organism dies. In a fossil less than 50,000 years old you would expect the ratio of 14C to 12C to be _____

answer

Lower, because the 14C is not replenished after death

question

The half-life of 14C, a radioactive element of carbon, is approximately 5,000 years. The ratio of 14C to 12C in a fossil 25,000 years old would be about _____ that of a living organism today

answer

1-32

question

Which would be the best way to determine the absolute age of a collection of sedimentary rocks that are thought to be between 50 and 200 million years old?

answer

Paleomagnetic dating

question

Scientists divide geological time into eras and periods. The _____ is most inclusive, and the boundaries are based on _____

answer

Era; changes on fossils

question

Plates of Earth's crust

answer

Can move via continental drift

question

The increase in the concentration of CO2 in Earth's atmosphere over the past 100 years _____

answer

Is primarily caused by the burning of fossil fuels by humans

question

In the process of _____, the _____ oceanic plate is forced _____ continental plate

answer

Subduction; Thinner; Under

question

Which group of organisms has been most affected by periods of increased glaciation?

answer

Marine life

question

What led to the mass extinction at the end of the Cretaceous period?

answer

A meteorite striking Earth

question

Which of the following about oxygen is true?

answer

It made aerobic metabolism possible

question

What is the most likely result of increased oxygen concentration on insects?

answer

Increase in body mass

question

For every described currently living species of organism, there are about _____ fossil species

answer

1/6

question

The Cambrian explosion took place over _____ years

answer

More than 50 million

question

Coal is the fossilized remains of _____

answer

Tree ferns and horsetails

question

Mass extinctions occurred at the end of each of the following periods except the _____

answer

Silurian

question

In the _____ period, fishes diversified and evolved jaws and club mosses, horsetails, and tree ferns became common. The earliest fossil terrestrial vertebrate and insects date from this period and there was a mass extinction at the end of the period that may have been caused by meteorite impacts

answer

Devonian

question

Over geologic time, the concentration of O2 in Earth's atmosphere has increased. During the end of the _____ period, the O2 concentration decreased significantly and resulted in _____

answer

Permian; Mass extinction

question

Gondwana is _____

answer

The southern part of the supercontinent after it broke in two

question

Around 5 million years ago, Earth was in the _____ era, and the _____ period

answer

Cenozoic; Tertiary

question

Where does meiosis take place in the moss life cycle?

answer

In the sporangium at the time of spore formation

question

Where does fertilization take place in the moss life cycle?

answer

In the archegonium of the gametophyte generation

question

Which set of terms represents a haploid/diploid pair?

answer

Spore/sporophyte

question

In conifers, male gametophytes are called _____ and are formed by the division of microspores

answer

Pollen

question

Which statement describes events leading to formation of offspring in the conifer life cycle?

answer

A haploid sperm from pollen enters the female gametophyte and fuses with a haploid egg

question

How do the sporophyte and gametophyte generations compare in a conifer?

answer

The sporophyte generation is much larger than the gametophyte generation and the two generations grow in a single individual

question

Double fertilization, which is a hallmark of angiosperm sexual reproduction, results in a _____

answer

Diploid zygote and a triploid endosperm

question

Which statement correctly describes the general pattern of the alternation of generations in angiosperms?

answer

The sporophyte generation (2n) produces spores (n) that produce gametophytes (n) that produce gametes (n) that fuse to produce a new sporophyte (2n)

question

Which structure is not a part of the sporophyte generation?

answer

Egg

question

A biologist discovers a seed-bearing plant that has never been classified. Which feature will help him determine whether the plant is a gymnosperm or an angiosperm?

answer

Female structures that produce an egg enclosed in a protective structure

question

Which of the following clades does not include algae?

answer

Embryophytes

question

Which of the following is a nonseed vascular plant?

answer

Fern

question

Which of the following characteristics is shared by all land plants?

answer

Alternation of generations

question

The sporophyte generation _____

answer

Extends from the zygote through the adult diploid plant

question

Which feature for obtaining water and minerals comes after the nonvascular plants in a phylogeny of the land plants?

answer

Extensive root systems

question

he dominant stage of the life cycle of a moss is the _____

answer

Haploid gametophytes

question

Which statement regarding vascular plants is true?

answer

The tracheid is the principal water-conducting element of the xylem in all vascular plants except the angiosperms

question

Both club mosses and horsetails _____

answer

Have simple leaves

question

Which of the following statements regarding the two leaf types (microphylls and megaphylls) is true?

answer

Microphylls arose from small, sterile sporangia

question

What might be the advantage of seeds with a dormant but viable state?

answer

Insuring the continuity of the species through time

question

All seed plants ____

answer

Are heterosporous

question

Seed Plants _____

answer

Produce spores by meiosis within the sporangia

question

A female conifer cone is made up of modified _____ and a male cone is made up of _____ along a central axis. The megastrobilus cone contains the _____ gametophytes and the microstrobilus, the _____ gametophytes.

answer

Branches; Modified leaves; Female; Male

question

Coniferous gymnosperms, such as pines, depend primarily on _____ for pollination, thus the plants produce large quantities of pollen that disperse over large areas during the spring

answer

Wind

question

How do angiosperms differ from gymnosperms?

answer

Angiosperms flower; gymnosperms do not

question

You examine two flowers of the same species but from two separate plants. One flower has only stamens, while the other flower has only a pistil. You would conclude that the species is _____, and the flowers are _____

answer

Dioecious; Imperfect

question

To determine how a flowering plant is pollinated, which structure or feature would be most important to examine?

answer

Morphology of the corolla

question

Which of the following correctly pairs a fruit and with a fruit type?

answer

Pear-Accessory

question

Which of the following statements about seeds is true?

answer

All seeds rely on animals for their dispersal; All seeds are fleshy and edible; All types of seeds are found in only gymnosperms; All seeds are brightly colored

question

How do monocots and eudicots differ?

answer

They differ in the number of cotyledons their seeds contain

question

Rhizomes stolonifer _____

answer

Has two distinct mating types

question

Which is a correct sequence in the life cycle of Rhizopus stolonifer?

answer

+ and - nuclei fuse → zygosporangium → sporangia → spores

question

A biologist is working on classifying a structure that she believes to be either a spore or a zygosporangium from a zygosporous fungus. What can the biologist do to make the distinction?

answer

Determine whether the structure is haploid or diploid

question

A student comments that a fungus such as Rhizopus stolonifer could go for many generations without ever carrying out meiosis, but not without carrying out mitosis. Evaluate the accuracy of this statement

answer

The statement is accurate

question

Fungi possess all of the following traits except _____

answer

Cell walls containing peptidoglycan

question

Unicellular fungi _____

answer

Are also called yeasts

question

The body of a multicellular fungus is called a _____. It is made up of _____ that may be septate or ______

answer

Mycelium; hyphae; coenocytic

question

Which statement about fungal nutrition is true?

answer

Fungi can break down cellulose and keratin

question

In what way do fungal decomposers contribute to Earth's carbon cycle?

answer

They return carbon atoms to the atmosphere in the form of respiratory CO2

question

Lichens are _____

answer

Most often a unicellular green alga in association with fungal cells

question

Which of the following could be a photosynthetic partner of a lichen?

answer

Cyanobacterium

question

A mycorrhizal association provides a plant with _____ and _____, and the fungus with _____ and _____

answer

Water; minerals; sugars; amino acids

question

Using a microscope, you are examining a cross section of a plant root in which hyphae surround the plant cells but do not penetrate them. You are most likely looking at _____

answer

Ectomycorrhiza

question

Both endophytic fungi and mycorrhizae _____

answer

Are important in plant growth

question

Reproduction in fungi _____

answer

Can occur asexually in unicellular fungi by budding

question

Sexually-reproducing fungi reproduce without distinct male and female structures because they _____

answer

Express genetically distinct different mating types instead of male and female structures

question

Which of the following characteristics is unique to the Fungi?

answer

Plasmogamy distant in time from karygamy

question

Zygomycota

answer

Possess many septa in their hyphae cells

question

Glomeromycota

answer

Are associated with 80%-90% of all plants

question

In most sac fungi, the ascospores are _____ and the hyphae are, _____. When the hyphae of two different mating types fuse, a _____ results

answer

Haploid; haploid; dikaryon

question

Which statement about sexual reproduction in Basidiomycota is true?

answer

The only diploid cells are those that contain fused nuclei

question

Sac fungus yeasts

answer

Are often unicellular

question

The basidium of a club fungus is equivalent to the _____ of a sac fungus

answer

Ascus

question

You are studying air pollution in New York City by documenting the abundance of lichens and the conditions likely to support them. What result are you likely to find?

answer

Lichens are not abundant due to air pollution

question

Obelia is an example of a cnidarian that reproduces sexually _____

answer

Sexually in its motile form and asexually in its sessile form

question

Which is a correct sequence in the life cycle of Obelia?

answer

Zygote → planula → polyp → medusae

question

In which structure does meiosis occur?

answer

Medusa

question

A biologist observes a single Obelia polyp on the sea floor not far from two large polyp colonies. What test could help determine whether the lone polyp arose from either or both large colonies as the result of asexual or sexual reproduction?

answer

Compare sequences of several genes isolated from all three groups of polyps

question

What are the two main groups of protostomes?

answer

Lophotrochozoans and ecdysozoans

question

Which feature distinguishes protostomes from deuterostomes?

answer

Position of blastopore in embryo

question

Which feature is found in the common ancestor of the deuterostomes?

answer

Pharyngeal slits

question

Which pieces of information support the idea that sea stars, acorn worms, and humans can be classified as deuterostomes?

answer

Embryological data and genetic information

question

What explains why echinoderms have radial symmetry even though genetic analysis clearly places echinoderms with the deuterostomes that all share a bilaterally symmetrical common ancestor?

answer

Echinoderms developed radial symmetry as a derived trait after splitting off from the common ancestor

question

A biologist discovers a new animal in a marine environment that has hexagonal radial symmetry. Of the following methods, which will best help him classify this organism with the deuterostomes or with some other group such as the ctenophores, sponges, or placozoans?

answer

Raise the animal in the lab and trace the its embryological development

question

What does the term "amphibian" mean?

answer

Double life

question

Which of the following statements about the frog life cycle is true?

answer

The internal gills in the tadpole are replaced by lungs in the adult

question

In which stage of the frog's life cycle does meiosis occur?

answer

Adult

question

Protostome animals _____

answer

Have a mouth derived from the blastopore

question

Which statement about the symmetry of organisms is true?

answer

Radial symmetry is found in echinoderms

question

Which statement about coelomate animals is true?

answer

They are triploblastic

question

Sponges

answer

Reproduce both sexually and asexually

question

Which statement about ctenophores is true?

answer

They have a complete gut

question

Which trait only occurs outside the lophotrochozoans?

answer

Radial symmetry

question

Parasitic flukes of vertebrates can devote most of their bodies to reproduction because they _____

answer

Acquire all of their nutrients from their host

question

Annelids

answer

Have a coelom

question

Which statement about mollusks is true?

answer

All mollusks have a shell

question

Ecysozoans

answer

All have a cuticle

question

Arthropods are the most numerous animals on Earth. Which trait was least important to their success?

answer

Molting

question

Which statement about crustaceans is true?

answer

Most have a body that is composed of three regions

question

Which trait is unique to deuterostome animals?

answer

Mouth formation on the end of embryos opposite the blastopore

question

Of the modern echinoderms _____

answer

All have a water vascular system

question

Which statement about the notochord is true?

answer

It is made up of large cells with turgid vacuoles

question

Which of the following best distinguishes amphibians and amniotes?

answer

Egg structure

question

In the not-too-distant past, the theory that birds were reptiles was met with skepticism. What type(s) of evidence support this theory being true?

answer

Molecular data

question

Marsupials differ from eutherians in that _____

answer

Gestation in marsupials is brief

question

Place the following groups of eutherians in order of decreasing species richness. (1) Bats (2) Elephants (3) Primates (4) Rodents (5) Shrews and moles

answer

4; 1; 5; 3; 2

question

Homo neanderthalensis _____

answer

Had a range that overlapped with that of Homo sapiens

question

Which of the following statements about air is correct?

answer

As air falls, it contracts and becomes warmer

question

Precipitation tends to be _____ on the _____ side of a mountain because water vapor _____ as it rises there.

answer

Higher; windward; condenses

question

The Cascade Mountains bisect the state of Washington into western and eastern portions. The western portion is bounded on its western border by the Pacific Ocean. The eastern portion is bounded on its eastern border by the state of Idaho. What might you predict about these two portions based on the information presented in the tutorial?

answer

Eastern Washington has a higher proportion of drought-resistant vegetation than western Washington

question

Which of the following biomes has the greatest annual rainfall?

answer

Tropical rain forest

question

Which of the following factors are important in determining the type of biome that characterizes a particular region?

answer

Temperature and precipitation

question

Which of the following sets of biomes is placed in order from lowest to highest average annual temperature?

answer

Tundra, woodland/shrubland, subtropical desert

question

Which of the following sets of biomes is placed in order from most to least biologically diverse?

answer

Tropical rain forest, temperate seasonal forest, tundra

question

Which of the following aquatic biomes is known for its high biological diversity?

answer

Coral reef

question

Which of the following sets of factors is important in distinguishing aquatic biomes?

answer

Water temperature, water depth, water currents, salinity

question

Which of the following sequences places the aquatic biomes in order from lowest to highest salinity?

answer

Stream, salt marsh, seagrass bed

question

Which of the following pairs of aquatic biomes shares the most similarities?

answer

Salt marshes and mangrove forests

question

An ecological system encompasses _____

answer

Biotic and abiotic factors

question

All of the field mice, grasshoppers, deer, hawks, and plants in a particular valley in Ohio constitute a _____

answer

Community

question

The gut microbial community will be most similar between _____

answer

Identical twins

question

Humans often experience digestive problems after taking a course of antibiotics to treat a bacterial infection, because the antibiotics destroy the body's "normal" microbes. These microbes do all of the following except _____

answer

Increased the flow of water out of the cells

question

How are climate and weather related to each other?

answer

Climate is what is expected in a particular region, whereas weather is what actually occurs

question

The beaches with the strongest sunlight in December can be found in _____

answer

Rio de Janeiro, Brazil

question

_____ energy drives global air circulation patterns

answer

Solar

question

Global oceanic circulation is driven by all of the following except _____

answer

Aquatic animals living in the oceans

question

Suppose that scientists discover a planet very similar to Earth. What information will be important in determining the growing seasons of the different regions on this new planet?

answer

Temperature and precipitation

question

Rain tends to be much more common in mountains than in the adjacent lowlands because _____

answer

Air cools as it travels up the mountains. Cool air holds less moisture than warm air, and the excess moisture is dropped as rain

question

Why does the leeward side of a mountain typically remain dry?

answer

As air descends the slope, it warms and picks up moisture from the environment

question

Different types of tropical biomes are determined primarily by the _____ in that zone

answer

Length of the dry season

question

The tundra biome is found _____

answer

At high latitudes and in high mountains

question

In aquatic biomes you would not expect to find photosynthetic organisms in the _____ zone

answer

Abyssal

question

A colleague brings you a sample containing an organism from an unknown location. It survives being subjected to dry conditions, continuous wave action, and full submersion in salt water but not in fresh water. This organism most likely comes from an _____

answer

Intertidal Zone

question

The common periwinkle, Littorina littorea, is a small marine gastropod. Based on the name, it is most likely found in the _____ zone

answer

Intertidal

question

Wallace's line is based on what kind of barrier to dispersal?

answer

A deep-water channel

question

Southern beeches, (genus Nothofagus), are found in South America, New Zealand, and Australia, as well as on certain islands of the southern Pacific Ocean. The most likely explanation for this widespread distribution is _____

answer

Continental Drift

question

Which statement about the effect of human activities on ecological systems is true?

answer

Human activities simplify natural ecosystems

question

When an ecologist designs a model to test a hypothesis about fires in a tropical savanna, knowledge about that ecosystem's _____ is vital

answer

Natural History

question

How do changing values for r affect the growth rate of a population?

answer

Populations grow when r is positive, remain constant when r is zero, and shrink when r is negative

question

What is meant by the term "doubling time" and how did changing values for N0 affect the doubling time of a population?

answer

Doubling time is the amount of time needed for a population to double in size; increasing N0 did not change the doubling time

question

The equations used in the tutorial apply to populations over short time intervals. Why can they not be applied to populations over very long time periods?

answer

Real populations are affected by resource limitations that are not accounted for in the equations

question

How long will it take a population of 550 moose to double if 25 offspring are born and 14 moose die on average per year?

answer

34.5 years

question

What is carrying capacity?

answer

The number of individuals in a population that can be supported by an area

question

If the size of a population is greater than the carrying capacity (K), what will happen to the population?

answer

The population will experience more deaths than births

question

According to the results of the simulation, how does distance affect the probability of extinction of subpopulations within a metapopulation, assuming that dispersal is active within the range of distances involved?

answer

The greater the distance between subpopulations, the greater the probability of extinction

question

According to the results of the simulation, which subpopulations within a metapopulation are most likely to go extinct?

answer

Small subpopulations separated by large distances with no dispersal

question

A biologist is studying a metapopulation of a turtle species. He counts the number of eggs laid by this species in each subpopulation within the metapopulation. The subpopulations range in size from very large to very small. The following are different possible outcomes of this study. Which outcome would suggest that the subpopulations are open systems rather than closed systems?

answer

The number of eggs counted over many breeding seasons remained fairly constant across all subpopulations

question

For which population would density best be measured per unit of volume, instead of per unit of area?

answer

Earthworms in the soil in Pennsylvania

question

You know that the population density of rabbits in an area is 80 individuals per square kilometer. The birth rate is 0.04 per week, and the death rate is 0.03 per week. From this information, population size would be calculated by _____

answer

Multiplying the occupied area by 80

question

In a population of 400 deer, the per capita birth rate is 0.16 per year and the per capita death rate is 0.22 per year. In the following year, you would expect a(n) _____ of _____ deer in this population

answer

Decrease; 24

question

There are 300 individuals in a population at time x. During the next month, 60 individuals are born and 30 die. What is the per capita growth rate per month?

answer

0.1

question

If b, the per capita birth rate, is higher than d, the per capita death rate, which of the following is most likely to occur?

answer

The population will grow because r > 0

question

The survivorship of five-year-old foxes is 0.34. The fecundity of these foxes is 0.54. What is the mortality of five-year old foxes?

answer

0.66

question

You are experimenting with sunflower photosynthetic rates. You expose different plants to different light intensities, ranging from no light to full sun. What type of relationship would you expect to see between increasing light intensity and rate of photosynthesis?

answer

The rate of photosynthesis would increase but eventually level off

question

The principle of _____ states that once an organism has acquired a unit of some resource, that bit of resource cannot be used for multiple functions at once

answer

Allocation

question

Which population cannot survive indefinitely?

answer

One with a per capita birth rate of 0.05 and a per capita death rate of 0.08

question

A hypothetical population not constrained by environmental limits would experience _____ growth

answer

Multiplicative

question

The number of individuals of any particular species that can be supported by a particular environment is known as _____

answer

The carrying capacity

question

An exponentially growing population of skunks has a doubling time of 10 years. In 2013 it had a population of 3,000. If it continues to grow at this rate, the population size will be _____ in the year 2033

answer

12,000

question

At carrying capacity, r is _____

answer

Zero

question

The current human population per capita growth rate is _____

answer

Positive, but lower than i twas in 1963

question

The set of subpopulations in an area make up a _____

answer

Metapopulation

question

The difference between the BD growth model and the BIDE model is the inclusion of _____ in the BIDE model

answer

Immigration and emigration

question

By necessity, in the BD model (not the BIDE model), populations are considered to be _____

answer

Closed systems

question

Fishermen prefer to catch _____ rockfish, and this has led to a(n) _____ in the size of rockfish

answer

Larger: decrease

question

The most effective way to reduce the number of ticks that cause Lyme disease in an area would be to _____ the number of _____

answer

Decrease; Small mammals

question

In Janzen's experiment, which of the following conditions describes his control group?

answer

Acacia trees that are left undisturbed

question

In Janzen's experiment, which of the following actions was performed on the experimental group?

answer

Acacia trees were fumigated to remove ants

question

Suppose that Janzen had found no difference in survival rates of acacia trees in his control and experimental groups. Which of the following conclusions would he have drawn?

answer

A mutualistic relationship may exist because trees may benefit in some way (e.g., reproductive success) not revealed by this experiment

question

If two organisms use the same resources and those resources are insufficient to supply their combined needs, the organisms' interactions constitute _____

answer

Competition

question

Predation is the type of interaction in which _____

answer

One participant is harmed while the other benefits

question

Mutualism is the type of interaction in which ____

answer

Both participants benefit

question

Commensalism is the type of interaction in which _____

answer

One participant benefits and the other is unaffected

question

Guppies (fish) swimming in a stream disrupt the growth of algae without any effect on the fish. This relationship can best be described as _____

answer

Amensalism

question

If you set up an experiment pairing different species of Paramecium together, under what circumstance would one species be least likely to go extinct?

answer

Mutualism

question

A population of plants has a per capita growth rate of -0.12 per year. The presence of a mutualistic aphid increases this rate by 0.002 per aphid per square meter. Keeping the per capita growth rate of the plant above zero requires a _____ density of aphids of _____ per m2

answer

Minimal; 61

question

At low densities and in the absence of any other beetle species, the population of a strain of the flour beetle Tribolium castaneum grows at a per capita rate of 0.3 per week. In controlled lab conditions, the per capita growth rate is reduced by 0.015 for every 100 individuals. The addition of a related beetle, Tribolium freemani, further reduces the per capita growth rate of T. castaneum by 0.02 for every 100 T. freemani individuals. If there are 800 T. castaneum and 500 T. freemani individuals, what is the per capita growth rate of the T. castaneum population?

answer

0.08

question

Which factor is most likely to promote the coexistence of competing species via rarity advantage?

answer

Interspecific competition being weaker than intraspecific competition

question

In a mythical world, Kelters eat Fygons and Joosts. Joosts are autotrophs, while Fygons eat autotrophs. Based on this information you would conclude that Kelters are _____

answer

Omnivores

question

Which statement about primary consumers is true?

answer

They are herbivores

question

The Muir effect _____

answer

Expresses the idea that different components of food webs are often interdependent

question

Species introduced to regions outside their original range that then spread widely and become abundant at a cost to the native species of the region are known as _____ species

answer

Invasive

question

Defensive strategies are most likely to evolve in ______

answer

The resource of a consumer-resource relationship

question

A plant species produces a chemical that is toxic to herbivores. Over time, herbivores that can detoxify the chemical increase in frequency. A mutation in the plant produces a new, different toxic chemical that the herbivores cannot detoxify. This is an example of _____

answer

An evolutionary arms race

question

Which relationship is most likely to lead to resource partitioning?

answer

Interspecific Competition

question

Trading of goods and/or services between individuals of different species _____

answer

Is most likely to be found in mutualists

question

Which statement about mutualisms is false?

answer

They are highly stable

question

At Glacier Bay, Alaska, the gravel deposits left behind by a retreating glacier were colonized first by which of the following organisms?

answer

Microorganisms

question

At Glacier Bay, Alaska, why were Dryas (an herbaceous plant) and alder trees among the first plants to appear during the ecological succession of gravel deposits left behind by a retreating glacier?

answer

Dryas and alder trees have nitrogen-fixing bacteria in nodules on their roots

question

After reading about the changes at Glacier Bay, a student remarks that the pattern and interactions of organisms present at each stage in succession creates the conditions that lead to the pattern present at the next stage. A second student remarks that the soil produced at each stage of succession helps define the pattern present at the next stage. Evaluate these two statements

answer

Both statements are accurate

question

According to results from the simulation in the tutorial, which island characteristics are associated with the highest species richness?

answer

Large and close to the mainland

question

Which statement is supported by the MacArthur-Wilson model simulation?

answer

Species diversity depends on the rates of colonization and extinction, which depend on the size and location of an island

question

A tsunami strikes a large peninsula, destroying the bird populations living there. The tsunami also fragments the peninsula into three islands of similar size but different distances from the mainland. What would the MacArthur-Wilson model predict about bird populations on these islands in the future?

answer

The rates of colonization of bird species will decrease with increasing distance of the island from the mainland, leading to lesser diversity with distance

question

As a forest becomes fragmented into smaller and smaller patches, the effects of fragmentation on these patches _____

answer

Increase

question

The microclimate at the edge of a forest fragment differs from that inside the forest. Which of the following is generally true of the edges compared to the interior of the forest?

answer

The edges have lower humidity

question

Ideally, what should a land use committee do as it maps out areas of undeveloped land to convert to human housing?

answer

Maximize the ratio of land area to edge length of a single undeveloped land fragment that will remain after development

question

A group of species that coexist and interact with one another in a defined geographic area is a _____

answer

Community

question

What is the difference between species composition of a community and community structure?

answer

Community structure takes into account the abundance of different species in a community, while species composition does not

question

An ecologist measures off a transect running through a park and identifies plants at regular intervals. The transect passes through various types of soils. As she moves through the transect she observes that some plants thin out as new ones appear, but that this change is gradual. This pattern is called _____

answer

Species turnover

question

Which process does not contribute to species composition changes over short periods of time?

answer

Evolution

question

A researcher is comparing the heights of the tallest plants found in communities where pollinators are abundant to those in communities where pollinators are scarce. The researcher is testing whether there is a relationship between _____ and pollinators

answer

Habitat Structure

question

In 2011, a tornado tore through Springfield, Massachusetts, destroying a large proportion of the trees in the area. This event is an example of _____, and the subsequent growth of new trees is an example of _____

answer

Disturbance; succession

question

The GPP of a community is 40 units per day on average, while the NPP of the community is 15 units per day. How many units are used for cellular respiration and other catabolic processes of the plants?

answer

25

question

GPP and NPP are most closely associated with _____

answer

Community function

question

The NPP of a community is 150 units per month and the GPP is 240 units per month. If the ecological efficiency of herbivores is 1/6, how many units of plant biomass are converted into biomass of herbivores?

answer

25

question

You are a scientist designing an experiment to investigate NPP over large expanses of Earth's surface. Which of the following could be measured by satellite to correlate with NPP?

answer

Sunlight absorption by chlorophyll

question

Productivity in a community _____ with increasing species number and _____ with an increase in the number of functional groups

answer

Increases; decreases

question

Which community has the highest species diversity?

answer

Community 3, with four equally abundant species

question

There are five species of beetles of roughly equal abundance in a community. A storm substantially reduces the population of one species. This would result in a decrease in species _____ and no change in species _____

answer

Diversity; richness

question

Species richness is highest in the _____

answer

Tropics

question

Islands that are _____ and _____ the mainland tend to have the most species

answer

Large; near

question

The mammalian fauna of an island is behaving in accordance with the MacArthur and Wilson theory of island biogeography. If the food supply on the island is permanently reduced, you would expect the number of mammalian species to _____, because _____ will _____

answer

Decrease; extinction; increase

question

An island is at equilibrium in terms of species richness when the _____

answer

Immigration rate is equal to the extinction rate

question

Earthworm activity adds nutrients and oxygen to the soil and makes it more homogenous. Thus, this soil has more value for agriculture. Which term best describes the agricultural value of earthworms?

answer

Ecosystem service

question

Based on the theory of island biogeography, fragmentation should have the least effect when _____

answer

Patches are close to one another

question

Wolves are crucial for maintaining healthy aspen forests because of their effects on _____

answer

Trophic cascades

question

Which of the following is the major compartment for carbon in Earth's system?

answer

Fossil fuels

question

How are humans influencing the carbon cycle?

answer

By cutting forests and burning biomass, which increase the atmospheric pool of CO2; Through changes in land use, which increase the atmospheric pools of CO2 and CH4; By burning fossil fuels and manufacturing cement, which increase the atmospheric pool of CO2

question

By what process does nitrogen enter the living components of ecosystems?

answer

Through fixation by microbes

question

How are humans influencing the nitrogen cycle?

answer

By increasing the rate of nitrogen fixation through industrial processes and intensive agriculture; By increasing the production of oxides of nitrogen and other chemical forms through livestock production and some forms of agriculture; By increasing the production of oxides of nitrogen and other chemical forms through burning fossil fuels and biomass

question

Which pathway represents the shortest path that a nitrogen atom in atmospheric nitrogen, N2, could travel and end up in a protein in a human?

answer

N2 → bacterium → plant → human

question

A student remarks that it is a good thing that humans discovered how to use industrial processes to fix nitrogen because this ensures that the nitrogen cycle can remain intact if nitrogen-fixing bacteria ever go extinct. Evaluate the accuracy of this statement.

answer

The statement is inaccurate because humans would not be able to distribute the product of nitrogen fixation from industrial processes in the same way that bacteria are able to distribute it globally now

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