AP biology final review

Most cells that have become transformed into cancer cells have which of the following characteristics when compared to normal, healthy cells?

Shorter cell cycle

Upon chemical analysis, a particular polypeptide was found to contain 145 amino acids. How many peptide bonds are present in this protein?

144

A cell in the testis of a male chimpanzee (Pan troglodytes) contains 48 chromosomes. It is about to undergo meiosis. How many molecules of DNA will be present in the nucleus of the sperm cells just after the second meiotic division?

24

In an ecosystem where the plants comprise 25,000 kg of biomass, about how many kilograms of carnivore biomass can be supported by these producers?

250 kg

If an organism that is homozygous recessive for a trait is crossed with a heterozygote, what is the chance of getting a homozygous recessive phenotype in the first generation?

50%

The mechanism of action of many common medications involves interfering with the normal pathways that cells use to respond to hormone signals. Which of the following best describes a drug interaction that directly interferes with a signal transduction pathway?

A medication enters the target cell and inhibits an enzyme that normally synthesizes a second messenger.

Which organism is most likely not functioning as a keystone species in its ecosystem?

A population of zebra mussels that compete with native species, reducing the biodiversity of the Great Lakes ecosystem

A population of armadillos inhabits a vacant field across the street from your neighborhood elementary school. Which of the following activities in the ecological community surrounding the armadillo habitat will decrease K for this population?

A real estate developer purchases land next to the vacant lot and builds a strip shopping center on it.

Which of the following effects is produced by the high surface tension of water?

A water strider can walk across the surface of a small pond.

The endocrine system incorporates feedback mechanisms that maintain homeostasis. Which of the following demonstrates negative feedback by the endocrine system?

After a meal, blood glucose levels become elevated, stimulating beta cells of the pancreas to release insulin into the blood. Excess glucose is then converted to glycogen in the liver, reducing blood glucose levels.

Which of these conditions should completely prevent the occurrence of natural selection in a population over a period of time?

All variation between individuals is due only to environmental factors.

How does natural selection influence the development of altruistic behaviors?

Altruistic behaviors lower stress in populations, which increases the survivability of all the members of the population.

The vertebrate forelimb initially develops in the embryo as a solid mass of tissue. As development progresses, the solid mass near the end of the forelimb is remodeled into individual digits. Which of the following best explains the role of apoptosis in remodeling of the forelimb?

Apoptosis involves the regulated activation of proteins in specific cells of the developing forelimb that leads to the death of those cells.

Antidiuretic hormone (ADH) is important in maintaining homeostasis in mammals. ADH is released from the hypothalamus in response to high tissue osmolarity. In response to ADH, the collecting duct and distal tubule in the kidney become more permeable to water, which increases water reabsorption into the capillaries. The amount of hormone released is controlled by a negative feedback loop. Based on the model presented, which of the following statements expresses the proper relationship between osmolarity, ADH release, and urine production?

As tissue osmolarity rises, more ADH is released, causing less water to be excreted as urine.

Of the mutation types below, which one is least likely to affect the function of the protein corresponding to the gene where the mutation occurs?

Base-pair substitution

A gardener is concerned that her greenhouse is getting too hot from too much light, and seeks to shade her plants with colored translucent plastic sheets. What color should she use to reduce overall light energy, but still maximize plant growth?

Blue

Mature red blood cells are anucleate; that is, they have no nucleus. What cellular function are mature red blood cells unable to perform?

Cell division

High levels of cholesterol are considered a major risk factor for heart disease. If cholesterol is so bad for humans, why do cells continue to manufacture it in the first place?

Cholesterol is used as a component of cell membranes and the base for certain hormones.

When homeowners in Allen mow their lawns, they often collect clippings and bag them up, leaving them out at the curb to be picked up on trash collection days. Your keen environmental awareness empowers you to approach the city council to propose a city ordinance prohibiting this practice. The council asks that you propose a potential solution to this problem. Which of the actions below would provide the greatest benefit for the local suburban ecosystem?

Collect the lawn clippings and add them to a compost pile, don't collect the clippings and let them decompose into the lawn, or apply composted clippings to the lawn.

The overall reaction for photosynthesis is: 6CO2 + 6H2O + light energy ➞ C6H12O6 + 6O2 If the input water is labeled with a radioactive isotope of oxygen, 18O, then the oxygen gas released as the reaction proceeds is also labeled with 18O. Which of the following is the most likely explanation?

During the light reactions of photosynthesis, water is split, removing electrons and protons, and oxygen gas is released.

The Piney Woods of eastern Texas is home to a wide variety of organisms ranging from the grass Longleaf Oats to coyotes. Which of the following best explains why these varied species can live together in this particular ecosystem?

Each species occupies a different niche.

Experts in white-tailed deer ecology generally agree that population sizes of deer that live in temperate climates are limited by winter snow. The deer congregate in "yarding" areas under evergreen trees because venturing out to feed in winter is energetically too expensive when snowfall depths accumulate to above 40 cm. Deer often stay yarded until the spring thaw. Snow depth over 40 inches for more than 60 days results in high mortality due to starvation.This observation best illustrates which of the following principles about factors that limit distribution of organisms?

Environmental factors are limiting not only in amount but also in longevity.

Epinephrine is a protein hormone found in many animals. Epinephrine stimulates a signaling pathway that results in the breakdown of glycogen to glucose in the liver cells. Which of the following describes the initial steps in the process whereby epinephrine stimulates glycogen breakdown?

Epinephrine binds to a cell-surface receptor; the activated receptor stimulates production of the second messenger, cAMP .

A protein is synthesized in the cytoplasm and then transported to the plasma membrane. Which of the following summarizes the protein's pathway in the cell?

Rough ER ➔ Golgi body ➔ vesicle ➔ plasma membrane

When a cell has a large surface area to volume ratio, what is the effect on its function?

Faster loss of heat

Experimental evidence shows that the process of glycolysis is present and virtually identical in organisms from all three domains, Archaea, Bacteria, and Eukarya. Which of the following hypotheses could be best supported by this evidence?

Glycolysis is a universal energy-releasing process and therefore suggests a common ancestor for all forms of life.

Specialized cells in the adrenal gland produce the hormone epinephrine and store it in vesicles. To release epinephrine these vesicles are carried to the plasma membrane and fuse with it. Which cellular organelles are involved in this process?

Golgi body, cell membrane, vesicle

Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then are herbivores (such as cows and horses) able to obtain an adequate nutrient supply by eating grasses?

Herbivores have mutualistic relationships with microorganisms in their digestive tracts that hydrolyze the cellulose to individual glucose subunits.

A population of birds colonizes an area in which the insects upon which they feed live inside trees. Which of the following events accounts for an observed increase in average beak size in the bird population over time?

Increased fitness of large-beaked birds, leading to natural selection

Enzyme molecules require a specific shape in order for them to perform catalysis of other molecules. Which of the following might alter the shape of an enzymatic protein?

Increasing the temperature of the reaction mixture containing the enzyme

Which of the following is true of mitosis?

It maintains the same chromosome number in the daughter cells as in the parent cell.

What is the value of the alcohol fermentation pathway?

It produces ATP.

Which of the following occurs in both meiosis and mitosis?

Separation of sister chromatids

Currently, two extant elephant species (L. africana and L. cyclotis) are placed in the genus Loxodonta, and a third species (E. maximus) is placed in the genus Elephas. Which of the following conclusions can be drawn based on the information provided?

L. africana and L. cyclotis share a greater number of homologies with each other than they do with E. maximus.

In some organisms such as certain fungi and algae, cells undergo mitosis repeatedly without subsequently undergoing cytokinesis. What would result from this?

Large cells containing many nuclei

The R group or side chain of the amino acid serine is -CH2-OH and is highly polar. The R group or side chain of the amino acid leucine is -CH2-CH(CH3)2 and is highly nonpolar. Where would you expect to find these amino acids in a globular protein in aqueous solution?

Leucine would be on the interior, and serine would be on the exterior of the protein.

Which of the following statements regarding the mitochondria is correct?

Mitochondria contain their own ribosomes and thus produce some of their own proteins.

Monarch butterflies are protected from birds and other predators because of cardiac glycosides they incorporate into their tissues from eating milkweed when they were in their caterpillar stage. The wings of a different species of butterfly, the Viceroy, look nearly identical to the Monarch so predators that have learned not to eat the bad-tasting Monarch avoid Viceroys as well. Scientists have recently discovered that Viceroy butterflies too are bad-tasting due to the metabolites in their tissues from the consumption of willows. This example best describes

Mullerian mimicry

Substances classified as hydrophobic, such as the fatty acid tails of a phospholipid are

Nonpolar substances that are repelled by water and do not form hydrogen bonds with it

A biologist wants to use a radioactive isotope of nitrogen to radiolabel certain molecules in a culture of cells she is growing. If the biologist uses 15N, which of the following groups of macromolecules will be labeled in the culture of cells?

Nucleic acids and proteins

Membrane-bound organelles have been an important component in the evolution of complex, multicellular organisms. Which of the following best summarizes an advantage of eukaryotic cells having internal membranes?

Organelles isolate specific reactions, increasing metabolic efficiency.

What is the purpose of oxygen in Aerobic Respiration?

Oxygen accepts electrons at the end of the electron transport chain.

A researcher examining a root tip observes a plant cell with condensed sister chromatids, kinetochores with attached microtubules, and individual chromosomes that are aligned at the equatorial plate of the cell. Which of the following best describes what the next process will be in the cell?

Paired chromatids will separate, and the new daughter chromosomes will move toward opposite poles of the cell.

A large assemblage of land snails is subdivided into two populations (A and B) by a river that effectively isolates the two populations for an indefinitely long period of time. From an evolutionary standpoint, which of the following is least likely to occur in the two populations?

Population A may undergo instantaneous speciation by the doubling of its chromosome numbers (polyploidy).

During mitosis, which of the following normally occurs?

Replicated chromosomes line up on the equatorial plate.

Epinephrine binds as a ligand molecule to receptors on the outside of liver cells, causing a cascade of chemical reactions to occur on the inside of the cell. Which pathway correctly describes what occurs after the ligand has bonded with the extracellular receptor protein?

Signal activates receptor's protein kinase ➔ G protein changes shape and transmits signal through phosphorylation ➔ protein kinases amplify signal through phosphorylation

Cell communication is critical for the function of both unicellular and multicellular eukaryotes. Which of the following is likely true of cell signaling?

Similar cell signaling pathways in diverse eukaryotes are evidence of conserved evolutionary processes.

The Miller-Urey abiotic synthesis experiment, among other similar experiments, provided evidence that

Simple organic molecules could form spontaneously under conditions such as those thought to be those of early Earth

In 1959, doctors began using the powerful antibiotic methicillin to treat infections of Staphylococcus aureus, but within two years, methicillin-resistant strains of S. aureus (MRSA) appeared. How did the resistant strains of S. aureus emerge?

Staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common.

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. Which of the following statements below is supported by the evidence provided above?

Succinate is the substrate, and fumarate is the product.

Which of the following best describes the role of cyclin in a dividing cell?

The accumulation of sand in an hourglass.

A biologist spent many years researching the rate of evolutionary change in the finch populations of a group of islands. It was determined that the average beak size (both length and mass) of finches in a certain population increased dramatically during an intense drought between 1981 and 1987. During the drought, there was a reduction in the number of plants producing thin-walled seeds. Which of the following procedures was most likely followed to determine the change in beak size?

The beak size in a large number of finches was measured every year from 1981 to 1987.

A culture of Amoeba proteus, a single-celled protistan that moves using pseudopodia, is exposed to a drug that inhibits the formation of microtubules. Which of the following choices correctly predicts what will occur?

The cells will move in place and will be unable to move from their location.

A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask.

The dissolved oxygen in the flask with algae will always be higher.

A biologist spent many years researching the rate of evolutionary change in the finch populations of a group of islands. It was determined that the average beak size (both length and mass) of finches in a certain population increased dramatically during an intense drought between 1981 and 1987. During the drought, there was a reduction in the number of plants producing thin-walled seeds.The biologist discovered that from 1988 to 1993, the average beak size declined to pre-1981 levels. The reversal in beak size from 1988 to 1993 was most likely related to which of the following events?

The end of the drought

Thermophilic bacteria such as Thermus aquaticus live in places like the geysers of Yellowstone National Park as well as the hot springs found in Hot Springs, Arkansas. T. aquaticus cells produce enzymes that function optimally at temperatures of 70°C or higher. At a temperature of 50°C, how will the enzymes in these bacterial cells most likely be affected?

The enzymes will not increase the rate of reactions as much as they would at 70°C.

The rough-skinned newt produces a toxin that can kill predators. Scientists have observed that some garter snakes can feed on the newts because they have a natural resistance to the toxin. In areas where populations of rough-skinned newts and garter snakes interact, which of the following predictions is best supported by evolutionary theory?

The garter snakes with resistance to the toxin will successfully reproduce and pass the trait on to their offspring.

A gene in cattle controls whether horns develop or not. When cattle without horns are mated together, none of the offspring ever has horns. A male with horns is mated with females without horns. If half of the offspring have horns and half do not, what is the conclusion?

The male is heterozygous.

By discharging electric sparks into a laboratory chamber atmosphere that consisted of water vapor, hydrogen gas, methane, and ammonia, Stanley Miller obtained data that showed that a number of organic molecules, including many amino acids, could be synthesized. Miller was attempting to model early Earth conditions as understood in the 1950s. The results of Miller's experiments best support which of the following hypotheses?

The molecules essential to life today could have formed under early Earth conditions.

Mammalian blood contains the equivalent of 0.15M NaCl. Seawater contains the equivalent of 0.45M NaCl. What will happen if red blood cells are transferred to seawater?

Water will leave the cells, causing them to shrivel and collapse.

The functionality of a protein is determined by its shape when it is in its native conformation. The native conformation of a protein is determined by the set of amino acids that compose the protein's sequence. A certain protein consists of 325 amino acids. What would be the result if one of the amino acids in this protein were changed?

The primary structure, tertiary structure and the biological function would all be altered.

A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 49 percent of the animals display a recessive trait (bb), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What is the most reasonable conclusion that can be drawn from the fact that the frequency of allele b has not changed over time?

The two phenotypes are equally adaptive under laboratory conditions.

Prairie dogs once covered the expanses of the Great Plains. Their grazing made the grass more nutritious for the huge herds of bison, and they were preyed upon by a variety of snakes, raptors, and mammals. In fact, the black-footed ferret (now endangered) specialized in prairie dog predation. Today, increases in housing and agricultural developments have eradicated many prairie dog towns. Which of the following statements about prairie dogs is true?

Their fundamental niche has been compromised.

About 13 different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the 13 species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction?

Their genomes should be more similar to each other than are the genomes of the five tree finch species.

The observation that chloroplasts and mitochondria each contain their own DNA and synthesize some of the proteins that function in these organelles suggests what?

These organelles must divide each time the cell containing them divides.

Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?

Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.

Areas along the coastal regions of continents have more moderate climates than their inland counterparts. What property of water allows this to be possible?

Water has a high specific heat.

Populations of Caribbean coral have decreased by nearly 80 percent over the past 30 years due to brown band disease caused by a group of protists called ciliates. Which of the following is most likely a major factor leading to the increased amount of brown band disease in the coral?

Water temperatures have increased and favored the growth of harmful ciliate populations.

Adaptive radiation is thought to be the process by which the diversification of mammals occurs, such as at the end of the Cretaceous Period, when dinosaurs became extinct and mammals became more prevalent. Rates of adaptive radiation typically are at their highest in which of the following situations?

When new niches become available.

Normal hemoglobin is a tetramer, consisting of two molecules of β-hemoglobin and two molecules of α-hemoglobin. In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits

altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.

Which kind of metabolic poison would most directly interfere with glycolysis?

an agent that closely mimics the structure of glucose but is not metabolized

Polysaccharides, triglycerides, and proteins are similar in that they

are synthesized from subunits by dehydration reactions.

On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. Which type of reproductive isolation operates to keep the mosquitofish isolated, even when fish from different ponds are reunited in the same body of water?

behavioral isolation

Which activity would reduce biodiversity in a forest ecosystem?

clearing a large area and planting one species of hardwood tree that can be used for lumber

If chemical signals in the cytoplasm control the progression of a cell to the M phase of the cell cycle, then fusion of a cell in G1 with a cell in early M phase would most likely result in the

condensation of chromatin in preparation of nuclear division in both cells

Blacktip sharks normally reproduce sexually. In 2008, researchers at an aquarium in Virginia discovered that a blacktip female shark in their collection reproduced asexually through the process of parthenogenesis, in which no sperm is required to fertilize the egg. One disadvantage to this method of reproduction is:

decreased genetic diversity within the species

DNA replication occurs

during the S phase of the cell cycle

During aerobic respiration, electrons travel downhill in which sequence?

food → NADH → electron transport chain → oxygen

Although identical twins inherit exact copies of the same genes, the twins may look and act differently from each other because

gene expression may be affected by epigenetic factors that influence protein production

After strenuous exercise, a muscle cell would contain increased amounts of all of the following EXCEPT:

glucose

A molecule that is phosphorylated

has an increased chemical potential energy; it is primed to do cellular work.

All of the following processes produce ATP EXCEPT:

lactic acid fermentation

Recently, scientists noted that stained chromosomes from rapidly dividing cells, such as human cancer cells, contain numerous dark, dotlike structures. Chromosomes from older human cells that have stopped dividing have very few, if any, dotlike structures. The best generalization regarding these dotlike structures is that they

may increase the rate of mitosis in human cells

Where are the proteins of the electron transport chain in aerobic respirations located?

mitochondrial inner membrane

According to the data, the crickets at 25°C have greater oxygen consumption per gram of tissue than do the crickets at 10°C. This trend in oxygen consumption is the opposite of that in the mice. The difference in trends in oxygen consumption among crickets and mice is due to their

mode of internal temperature regulation

Cladograms (a type of phylogenetic tree) constructed from evidence from physical characteristics are based on similarities in

morphology

A human cell in prophase of mitosis can be distinguished from a human cell in prophase I of meiosis by the presence of

paired homologous chromosomes in the meiotic cell

When planting crops, farmers rotate the types of plants that are planted for harvest in order to prevent the soil from being leached of essential minerals. If a farmer plants a crop that leaches the soil of phosphorus, which of the following biomolecules will subsequent plants be unable to synthesize?

phospholipids

The volume enclosed by the plasma membrane of plant cells is often much larger than the corresponding volume in animal cells. The most reasonable explanation for this observation is that

plant cells contain a large vacuole that reduces the volume of the cytoplasm.

Sickle-cell anemia results from a point mutation in the HBB gene. The mutation results in the replacement of an amino acid that has a hydrophilic R-group with an amino acid that has a hydrophobic R-group on the exterior of the hemoglobin protein. Such a mutation would most likely result in altered

protein secondary structure as a result of abnormal hydrophobic interactions between R-groups in the backbone of the protein

Antibiotics have many mechanisms of action. Some antibiotics such as azithromycin act to inhibit the small subunit of bacterial ribosomes. If a person is being administered azithromycin for a bacterial sinus infection, which of the following biologically important compounds will the bacteria be unable to produce?

proteins

Glandular organs such as the pancreas and salivary gland produce a large quantity of enzymes used by the body on a daily basis. Cells of these organs would be expected to contain a large quantity of which organelle?

ribosome

Mutations in a gene sequence would have the most direct effect on the

sequence of building blocks of a protein found in a cell

Many scientists suggest that billions of years ago, life on Earth began with

simple, single-celled organisms

Liver cells are specialized cells that carry out a multitude of tasks, including the synthesis of cholesterol and the breakdown of protein metabolites. These cells would be expected to contain a large proportion of which organelle relative to all others?

smooth ER

Succinylcholine is structurally almost identical to acetylcholine, but if combined with the enzyme that normally hydrolyzes acetylcholine, the enzyme is no longer able to hydrolyze acetylcholine. This suggests that

succinylcholine must be a competitive inhibitor with acetylcholine