question

A scientific hypothesis has

answer

It is falsifiable

question

A scientific theory is

answer

an explanation supported by a very large amount of experimental evidence

question

What hypothesis was tested by Warren and Marshall during their research involving Helicobacter pylori bacteria and stomach ulcers?

answer

The cause of many stomach ulcers is the bacterium H. pylori, not spicy food.

question

If an inductively reasoned hypothesis makes sense, based on all available and historical observations, then

answer

the hypothesis might be false

question

Why are hypotheses never always accepted by scientists

answer

Alternative hypotheses might provide a better answer to the research question

question

Which of the following is a testable hypothesis

answer

Avoiding contact with other people reduces the chance of catching a cold.

question

Mehran has heard from some of his teammates that drinking a high protein supplement after football training will improve his muscle mass. He decides to test this hypothesis by comparing the muscle mass of teammates who drink the high protein drink with a control group who drink only water. Which of the following would be the best control for his experiment?

answer

randomly selected teammates in training who are given a placebo instead of a protein drink

question

The most effective control subjects in a test of an experimental treatment are

answer

treated the same as experimental subjects but not given the experimental treatment.

question

The purpose of double-blind experiments is to

answer

minimize the effects of human bias on the results

question

There is a strong correlation between stress and susceptibility to colds. This means that

answer

stress might or might not affect susceptibility to colds

question

The specialized branch of mathematics that is used to compare data is called

answer

statistics

question

When an experiment has a large sample size, and there is a large difference between the results in the experimental and control groups, it is ________ that the experimental results are statistically significant.

answer

very likely

question

If the reported confidence interval for a population mean is 95%, then there is a

answer

95% probability that the true mean is in the reported range.

question

What does it mean to say that experimental results are peer reviewed?

answer

The results are analyzed by other scientists before they are published.

question

A news report on CNN that describes recently published research on a new treatment for colds is an example of a(n)

answer

secondary source.

question

The most trustworthy source of scientific information is

answer

peer-reviewed research publications

question

According to scientific evidence, what is the best prevention method known for reducing the chance of contracting a common cold

answer

washing your hands frequently and effectively

question

Because the electrons in a water molecule are shared unequally between hydrogen and oxygen, water is said to be

answer

polar.

question

Imagine a newly discovered biological molecule that is mostly hydrophobic in its structure. This new molecule will most likely be classified as a

answer

lipid.

question

How do the concentrations of H+ and OH- compare to each other in an acidic solution?

answer

The concentration of H+ is higher

question

A solution with a pH of 2 has an H+ ion concentration that is ________ than a solution with a pH of 4.

answer

100 times higher

question

What is the name of a molecule composed of one or more sugars?

answer

carbohydrate

question

Proteins are polymers of

answer

amino acids

question

Which organelle contains digestive enzymes that degrade a variety of macromolecules?

answer

lysosome

question

Which organelle is found in plant cells but not in animal cells?

answer

chloroplast

question

Which organelle performs photosynthesis?

answer

chloroplast

question

Which organelle performs cellular respiration?

answer

mitochondrion

question

Cells contain proteins that help transport substances from the exterior to the interior of the cell. Where are these proteins found?

answer

plasma membrane

question

Which organelle is represented by a network of membranes involved in the production of proteins?

answer

endoplasmic reticulum

question

Microtubules, microfilaments, and intermediate filaments compose what part of a cell

answer

cytoskeletal elements

question

What kind of molecule forms a bilayer that is the basis for all cellular membranes

answer

phospholipid

question

Which feature is found in both prokaryotic and eukaryotic cells?

answer

DNA

question

According to the theory of evolution, which states that all life-forms on Earth arose from a common ancestor, all living organisms

answer

share a common organic chemistry

question

The plasma membrane of a photosynthetic eukaryotic cell

answer

isolates the cell's contents from the external environment.

question

Which of the following is a lipid?

answer

cholesterol

question

Nutrients that the human body requires in large quantities are called

answer

macronutrients.

question

When you compare tap water to bottled water, in most cases

answer

bottled water and tap water are equally clean.

question

Which macronutrient is the major source of energy for cell processes?

answer

carbohydrates

question

Table sugar (sucrose) belongs to which category of nutrients?

answer

carbohydrates

question

Why are whole foods better for your health than processed foods?

answer

Processed foods don't contain all the vitamins and minerals found in whole foods

question

Carbohydrates are an excellent source of energy for the body. If a candy bar and a pear contain an equal number of calories from carbohydrates, which is a healthier food and why?

answer

The pear is healthier because it contains more vitamins, minerals, and fiber.

question

Erin wants to make a stir fry using an unsaturated fat. Sam suggests that she use

answer

olive oil

question

Vitamins in the human body

answer

help enzymes function properly.

question

Sunlight is required for the synthesis of

answer

vitamin D.

question

Which of these statements is true about minerals?

answer

Minerals cannot be made by the body

question

What is a function of antioxidants?

answer

to decrease damage done to cells by free radicals

question

Which of the following best describes the structure of the plasma membrane?

answer

a double layer of lipids with proteins embedded in it

question

What does hydrophobic mean?

answer

repelled by water

question

What happens to excess protein in the body?

answer

It is stored as fat.

question

What is a major difference between saturated and unsaturated fats?

answer

Unsaturated fats contain carbon-to-carbon double bonds, but saturated fats don't.

question

Eating large amounts of food, followed by self-induced vomiting, is a type of eating disorder called

answer

bulima

question

Which of the following is associated with obesity?

answer

Type 2, noninsulin-dependent diabetes mellitus

question

What term describes a harmless, noncancerous or precancerous tumor?

answer

benign

question

Which of these people is most likely to use the most Calories during 20 minutes of exercise?

answer

a 30-year-old man who weighs 250 pounds

question

An infinite variety of enzymes and other proteins could be produced from the ________ amino acids in the human body.

answer

20

question

Why isn't a BMI (Body Mass Index) a perfectly reliable way to estimate your health?

answer

It doesn't account for differences in muscle mass between individuals.

question

What is the name for the region toward the middle of a replicated chromosome where sister chromatids are connected?

answer

centromere

question

HeLa cells

answer

were derived from a cancerous tumor in Henrietta Lacks

question

What is the correct order of events in the cell cycle?

answer

G1, S, G2, mitosis, cytokinesis

question

During which part of mitosis does the nuclear envelope break down?

answer

prophase

question

What is the name of the process by which cancer cells break off of tumors and spread to other parts of the body?

answer

meteastasis

question

________ is the cause of about one-third of all cancer deaths.

answer

Smoking tobacco

question

What are the two halves of a duplicated chromosome called?

answer

sister chromatids

question

During which phase of mitosis do sister chromatids separate to opposite poles of the cell?

answer

anaphase

question

Why do chromosomes resemble the letter X when viewed during metaphase?

answer

Because there are two sister chromatids joined at a point in the middle (the centromere).

question

What is the difference between oncogenes and proto-oncogenes?

answer

Proto-oncogenes encode proteins that help a cell divide under favorable conditions; oncogenes encode proteins that help a cell divide under unfavorable conditions.

question

Consider a cell that underwent mitosis but not cytokinesis. The result would be

answer

a cell with two nuclei.

question

A cell plate forms during which process?

answer

cytokinesis in a plant cell

question

During which phase of mitosis are the replicated chromosome aligned in the middle of the cell?

answer

metaphase

question

A gene that encodes a protein necessary for a cell to stop at checkpoints is an example of a(n)

answer

tumor-suppressor gene.

question

The surgical removal of cells, tissue, or fluid that will be analyzed to determine whether they are cancerous is called a ________.

answer

biopsy

question

Different versions of the same gene are called

answer

alleles.

question

The multiple-hit model of cancer means that

answer

multiple mutations are required to cause most forms of cancer.

question

Normal sperm or egg cells in a human

answer

have one copy of each chromosome

question

A normal human cell containing 22 autosomes and a Y chromosome is a(n)

answer

sperm cell.

question

Sister chromatids separate during

answer

meiosis II and mitosis.

question

Homologous chromosomes separate during

answer

meiosis I.

question

Crossing over occurs during

answer

prophase I of meiosis I.

question

The members of a pair of chromosomes (for example, the two copies of chromosome 1) are called

answer

homologous chromosomes.

question

A mistake made during copying of genetic information is called a

answer

mutation

question

Monozygotic (identical) twins are the result of

answer

one embryo splitting to become two embryos.

question

How does crossing over increase genetic diversity?

answer

Crossing over increases the number of distinct combinations of genes that may be present in a gamete.

question

Mutations are only passed from parent to child if the mutation occurs in the gonads that will be used to produce

answer

a gamete.

question

Which if the following is the correct sequence of how an animal is "built"?

answer

meiosis → fertilization → zygote → embryo

question

As a result of 25% of FF, 50% of Ff and 25% of ff; How many different types of offspring (genotypes) are possible as a result of this cross, according to the Punnett square?

answer

3

question

A mutation in a gene

answer

might have no effect on the protein encoded by the gene.

question

If the DNA contained in the chromosomes of an organism is similar to an instruction manual, then what are the genes "instructing" the cell to do?

answer

synthesize specific proteins from amino acids

question

Combined, your parents could have produced as many as ________ different types of children, genetically speaking.

answer

64 trillion

question

In humans, heterozygotes are referred to as ________, particularly when the recessive allele is associated with a genetic disease.

answer

carriers

question

Which of these describes influence on a trait that is due to genes and not environment?

answer

Jen has brown hair, just like her mother and father.

question

Cystic fibrosis is caused by the allele f, which is completely recessive to the normal dominant allele F. Consider a couple with the genotype Ff. What is the chance that their second child will develop cystic fibrosis?

answer

25%

question

Huntington's disease is caused by the allele H, which is completely dominant to the normal recessive allele h. Consider a couple where the man has the genotype Hh, and the woman has the genotype hh. What is the chance that their first child will develop Huntington's disease?

answer

50%

question

An individual who is a carrier for a recessive genetic disorder but does not have symptoms of the disorder is

answer

heterozygous

question

Consider a trait that shows continuous variation. If the variance is low, then

answer

the majority of individuals will be very close to the mean.

question

If the estimated heritability of a trait is approximately 0.50, then

answer

at least 50% of the variation in the trait in the population is due to genetic differences.

question

A scientist studying the heritability of IQ would expect to find the highest correlation between the IQ scores of

answer

monozygotic twins.

question

Which of these conditions is caused by nondisjunction of autosomal chromosomes?

answer

Trisomy 21 — Down syndrome

question

A normal human cell containing 22 autosomes and a Y chromosome is a(n)

answer

sperm cell.

question

A normal human cell containing 44 autosomes and two X chromosomes is a(n)

answer

somatic cell of a female.

question

Which of the following pairs of people would provide the most useful information to geneticists, regarding the heritability of a certain trait?

answer

monozygotic twins separated into different households soon after birth

question

There are NO sugars on the surface of any of the red blood cells for which blood type?

answer

type O

question

A woman with type AB blood has sugars on what percent of her red blood cells?

answer

100%

question

A child with type O blood could not have a parent with type ________ blood.

answer

AB

question

People with the same blood type

answer

may or may not be related.

question

A patient with which blood type can donate to anyone?

answer

type O

question

A patient with which blood type can receive blood from any donor?

answer

type AB

question

A woman with type AB blood and a man with type O blood have a child. Which type of blood could the child have?

answer

type A or type B

question

Describing a person as having hemophilia is to indicate his or her

answer

phenotype

question

In addition to excessive bleeding, persons with hemophilia may have excessive bruising, pain and swelling in the joints, vision loss, anemia, or neurological problems. This is a result of the effects of a single gene loss and is called

answer

pleiotropy

question

Sex-linked traits can be expressed in

answer

either males or females.

question

Hemophiliacs have blood that does not coagulate well, and they often die at a young age. The disease allele is recessive and X-linked. Which of the following is the BEST prediction about the offspring of a hemophiliac male and a nonhemophiliac female who is a carrier for the disease?

answer

Some males and females could be hemophiliac.

question

Hemophilia is a genetic disease that has plagued the royal houses of Europe. The disease allele is recessive and X-linked. Queen Victoria was a carrier, and her granddaughter Alexandra married Nicholas II, the last czar of imperial Russia. Alexandra was a carrier for hemophilia; Nicholas was normal. Their son, Alexis, was afflicted with the disease. Alexis and his four sisters were killed in 1917. It's most likely that

answer

at least one of the sisters was a carrier of the allele.

question

Hemophilia is an X-linked recessive allele causing a blood disorder. What are the chances that a daughter of a normal man and a woman, who is heterozygous for the disease, will have hemophilia?

answer

0%

question

Y-linked genes include a gene that produces hairy ears. A male with hairy ears should pass this trait

answer

only to his sons.

question

In humans, the sex of the offspring is ordinarily determined by the

answer

sex chromosome carried by the sperm cell.

question

A human sperm cell receives autosomes and

answer

either an X or a Y chromosome.

question

Humans possess

answer

1 pair of sex chromosomes and 22 pairs of autosomes.

question

When comparing the DNA fingerprints of a parent and child, the parent's DNA fingerprint will have which of the following genetic traits?

answer

DNA bands that match those in the child's fingerprint and that aren't from the other parent

question

The polymerase chain reaction (PCR) is used to

answer

make many copies of a small amount of DNA.

question

In DNA fingerprinting, amplified fragments of DNA are separated from one another by which process?

answer

electrophoresis

question

A DNA molecule consists of

answer

nucleotides.

question

A sequence of DNA codes for a

answer

protein.

question

The structure of a protein is determined by

answer

the sequence of the amino acids it contains.

question

The sequence of events in the process of protein synthesis is

answer

DNA → RNA → protein.

question

The process of copying a sequence of DNA nucleotides into a complementary sequence of RNA nucleotides is called

answer

transcription.

question

The process of copying a sequence of RNA into a protein is called

answer

translation.

question

Milk production in modern dairy cows has been dramatically increased because of

answer

recombinant bovine growth hormone.

question

If the process of protein synthesis in a cell is analogous to a politician's speech being written down by a reporter and then converted into a different language before being published, then the initial step (being written down by a reporter) corresponds to

answer

transcription

question

Recombinant proteins refer to proteins that have been made in which manner?

answer

by genetically modified bacteria

question

Genetically modifying crop plants can do which of the following?

answer

make the plants more resistant to freezing.

question

Genetically modified foods have resulted in

answer

rice that allows greater synthesis of vitamin A because it has β-carotene

question

A recombinant Ti plasmid can be used to

answer

insert genes from any source into a plant.

question

The possibly harmful environmental effects of GM foods includes

answer

the transfer of genetically modified genes to weedy relatives

question

Genetically modified tomatoes have been designed with which purpose in mind?

answer

having a longer shelf life in grocery stores

question

What are genetically modified organisms (GMOs) also called?

answer

transgenic organisms

question

Approximately ________ of the foods in American grocery stores contain at least small amounts of GMOs

answer

50%

question

Fears about GMO crops were amplified when

answer

Monarch butterflies appeared to die off as well as insect pests.

question

Data from the Human Genome Project might help scientists

answer

understand who might be susceptible to certain diseases.

question

The raw data from the human genome project consists of

answer

the order of the bases A, T, G, and C in human DNA.

question

The genomes have been sequenced of

answer

The Ebola virus.

question

What is an example of gene therapy?

answer

infecting a cystic fibrosis patient with a virus carrying a working copy of the cystic fibrosis gene

question

Which type of disease condition would most likely be successfully treated by gene therapy?

answer

a disease caused by a nonfunctional enzyme in the body

question

The undifferentiated cells that can be used in therapeutic cloning are

answer

stem cells.

question

Stem cells can be found in

answer

Cord blood.

question

Therapeutic cloning aims to produce ________ from stem cells.

answer

healthy tissues

question

The famous sheep "Dolly" was the result of

answer

nuclear transfer.

question

Different versions of the same gene are called

answer

alleles

question

This disease has been treated by gene therapy

answer

Hemopohilia and Cystic Fibrosis

question

What molecule remains in the nucleus during protein synthesis?

answer

DNA

question

What is the function of tRNA (transfer RNA) molecules during translation?

answer

They carry amino acids to the ribosome.

question

Students studying a population of salamanders in a pool mark each salamander caught as it's entering the pool. During the first spring migration to the pool, the students mark 200 salamanders. The following year, they again capture 200 salamanders. Of these, 20 were from the previous year. Students use this information to calculate that they captured ________ of the

answer

10%; 2000

question

The evenly spaced distribution of stalks of corn planted in an agricultural field is considered

answer

an uniform distribution

question

Red maple tree seeds are dispersed by the wind. This species of tree can be found in fields, woods, and even wetlands. This is an example of a ________ distribution.

answer

random

question

A population that's exhibiting exponential growth

answer

will have growth proportional to the current total.

question

In a particular county, there are 30 births and 20 deaths for every 1000 residents. What is the annual growth rate of this population?

answer

1.0%

question

Over the past two centuries, the growth of human population has

answer

increased exponentially.

question

As the Industrial Revolution took place, there was a decrease in infant mortality, resulting in

answer

an increase in the population growth rate.

question

When considering the growth of the human population, how is the annual growth rate determined?

answer

the number of births averaged over the population as a whole minus the number of deaths averaged over the population as a whole

question

True or false: In general, developed countries have lower population growth rates than less developed countries.

answer

true

question

When you look at the spacing of humans on a global level, the population follows a(n) ________ distribution

answer

clumped

question

Approximately how many people are on Earth today?

answer

7.2 billion (7,200,000,000)

question

A death rate of 2.1% would represent 21 deaths per ________ individuals in a population per year

answer

1000

question

Developed countries are characterized by

answer

industrial economies and high individual incomes.

question

Increased mortality in a population due to increased competition for water is the effect of

answer

density-dependent factor.

question

Scientists calculate the carrying capacity of the earth is nearly ________ people.

answer

21 billion

question

A population has reached the carrying capacity of the environment when

answer

the environment can't support a further increase in the population.

question

Growth rates appear to be declining in many human populations because

answer

educated women are choosing to have fewer children.

question

Americans make up less than ________ of the total human population, yet use close to ________ of the world's resources.

answer

5%; 25%

question

The current rapid loss of species is considered by many scientists to be another mass extinction. This increase in extinction rate, beyond background extinction, is thought to be due to

answer

human population growth and the resulting habitat changes worldwide

question

Fenway Park, home of the Boston Red Sox, is situated on land that was once a fen, a kind of wetland. The replacement of the fen is an example of

answer

habitat destruction

question

) Purple loosestrife is a beautiful, long-stemmed wetlands species brought to the United States from Europe as an ornamental plant. In the United States, it has no predators and crowds out cattails, another wetlands plant that's a valuable resource for many species. Purple loosestrife is an example of

answer

an introduced species.

question

The North Atlantic Right Whale was called the "right whale" because they were the best whale for early whalers to kill. They have long baleen and lots of blubber and oil. When killed, they could be towed back to land for processing because they float. They once numbered in the millions, but the entire population of the species is now less than 400. The history of the right whale is an example of

answer

overexploiation

question

The World Wildlife Federation recently reported that the number of animals world-wide has decreased by _________% in the last 40 years

answer

50

question

There have been ________ mass extinctions experienced on a global scale before the alarming mass extinction that's now occurring.

answer

five

question

North America is currently experiencing an unprecedented and rapid loss of species. What is believed to be the main trigger of such events, either directly or indirectly?

answer

increased human population

question

What law was passed to address the problem of rapid species loss in the United States?

answer

the Endangered Species Act of 1973

question

The variety of species in an area of interest is called

answer

biodiversity

question

The average lifespan of a species on Earth is estimated to be around ________ years.

answer

1,000,000

question

What presents the greatest threat to biodiversity?

answer

habitat loss or degradation

question

Which of the following threats to biodiversity isn't directly due to humans?

answer

loss of habitat due to volcanic activity

question

The runoff of fertilizers from agricultural and residential areas can cause the aquatic algae in bodies of water to grow prolifically, resulting in a phenomenon called

answer

eutrophication

question

"Colony collapse disorder" is thought to be due to an increase in ________ of honeybees.

answer

parasites

question

Ants live in bull's horn acacia trees. The ants will attack any predators of the tree. In return, the ants live protected in the thorns of the tree and eat the nectar and protein-rich secretions of the tree. This is an example of

answer

mutualism

question

Cattle egrets hitch a ride on domestic cows and eat insects that are stirred up by their activity. This is an example of

answer

commensalism

question

A woman is more susceptible to vaginal yeast infections when taking antibiotics because

answer

the normal bacteria in the vagina are also killed by the antibiotic and can't competitively exclude the yeast

question

Extracts of the rosy periwinkle have provided drugs now available for treating cancer. The ability to find this species of plant and discover these drugs is a strong argument for

answer

preserving biodiversity

question

During the 1980s, wolves were reintroduced to Yellowstone National Park after decades of absence due to extermination. Within 20 years, not only had the wolf population increased, but there was also a dramatic increase in other species, such as aspen, cottonwood, and willow trees, beavers, warblers, insects, and fish. This is an examples of how important a(n) ________ is.

answer

keystone species

question

Salmonella causes a food-borne illness that kills Americans each year. It is found mainly in poultry products. Rather than give large doses of antibiotics to poultry, some poultry producers infect the intestinal tract of hens with a harmless bacteria, resulting in a dramatic decrease of Salmonella found in the chickens. The producers have used the principle of

answer

competitive exclusion.

question

There is an article in your local newspaper about an upcoming "Biodiversity Day" event at your university. Because you understand why it's important to conserve biodiversity after studying biology, you plan to attend. Your younger brother tells you he doesn't understand how the loss of a few species or habitats in town can have any impact on anyone's life. You could tell him

answer

a decrease in biodiversity could result in a loss of species that could provide humans with new drugs to cure disease.

question

A species that has a high number of alleles for many genes that are distributed throughout the population is said to have

answer

high genetic variability

question

) Is a species that has few individuals at greater risk of extinction than a species with a large population size? Why or why not?

answer

Yes. A species with few individuals is more likely to be eliminated by a reduction in population size caused by a chance environmental event like bad weather or a fire.

question

Los Angeles, California, has an average daily temperature between 70° F and 80° F throughout most of the year. There's very little rainfall except for during a rainy season beginning in the fall. This describes the city's

answer

climate

question

What city would have the largest variation in daylight hours between the summer solstice and the winter solstice?

answer

Montreal, Canada

question

Compared to the air above a nearby land mass, the air above a large body of water is

answer

cooler in summer.

question

Which of the terrestrial biomes is dominated by woody plants?

answer

chapparal

question

When all living organisms are included, ________ contain about 70% of the biomass found on Earth's land surface

answer

forests

question

What type of land biome is commonly found at 30 degrees North and 30 degrees South?

answer

desert

question

When a patch of land is cleared in a tropical rainforest, the vegetation is often burned to enrich the soil with nutrients from the burned plant material. This

answer

works for a few years, but the soil is soon depleted of nutrients.

question

Coniferous trees are most abundant in

answer

boreal forests

question

An environment where the plants are low to the ground and many boggy areas are found is called

answer

a tundra

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