Bio 101 Weekly Quizzes Study

In 2010, Dr. Svante Pääbo published research indicating that all modern ethnic groups other than Africans carry traces of Neanderthal DNA in their nuclear genomes. His earlier work indicated no overlap between Neanderthal mitochondrial DNA and that of Homo sapiens. Which of the following is NOT a likely possible hypothesis that could be supported by this information? A. The shared nuclear DNA could be a remnant of DNA from a common ancestor shared by Neanderthals and Homo sapiens. B. The shared nuclear DNA is definitely the result of interbreeding between female Neanderthals and male humans. C. The shared nuclear DNA could be the result of interbreeding between male Neanderthals and female Homo sapiens. D. The shared nuclear DNA could be a remnant of DNA from Homo erectus, one of the most recent species since Australopithecus.

B. The shared nuclear DNA is definitely the result of interbreeding between female Neanderthals and male humans.

When sodium chloride (Na+Cl-) is dissolved in water, the sodium ion is? A. attracted to the hydrogen atoms of water molecules. B. attracted to the oxygen atoms of water molecules. C. attracted to other sodium ions that are being dissolved. D. repelled by the oxygen atoms of water molecules.

B. attracted to the oxygen atoms of water molecules.

Jim is mowing the lawn and accidently runs over a large round object that seems to explode in a cloud of dust. Upon closer examination, he determines that the object was actually the club-shaped reproductive structure of an organism that has cells with cell walls but no chloroplasts, and the dust particles were actually spores. This organism is probably a __________ that belongs to kingdom __________ A. ascomycete; Plantae B. basidiomycete; Fungi C. zygomycete; Fungi D. basidiomycete; Plantae

B. basidiomycete; Fungi

Based on Mendelian inheritance, would it be necessary to have both the genotype and phenotype for an organism when attempting to predict the inheritance pattern for a trait in offspring? A. Yes; individuals with different genotypes often have the same phenotype. B. Yes; individuals with different phenotypes often have the same genotype. C. No; knowing the phenotype will indicate the genotype. D. No; knowing the genotype will indicate the phenotype.

D. No; knowing the genotype will indicate the phenotype.

If a segment of double-stranded DNA has 20 percent adenine (A), how much of it is cytosine (C)? A. 30 percent B. 40 percent C. 20 percent D. 60 percent

A. 30 percent

Gamete formation in human males is different from gamete formation in human females in that human male: A. produce gametes in the gonads, whereas human females produce eggs in the gut. B. make sperm throughout their lives, beginning at puberty, whereas human females are born with all their primary oocytes poised to develop into eggs that may be fertilized. C. make two polar bodies during spermatogenesis, whereas human females do not. D. have a shorter reproductive life span than human females.

B. make sperm throughout their lives, beginning at puberty, whereas human females are born with all their primary oocytes poised to develop into eggs that may be fertilized.

The fossils of organisms that existed when the continents were connected are distributed across __________ continents than the fossils of organisms that evolved after the continents separated. A. fewer B. more C. younger D. older

B. more

A tiny insect known as an aphid obtains nutrition by poking a mouthpart into the stem of a plant. Once the aphid's mouthpart is inserted, fluid from the plant is pushed through the aphid's digestive tract by pressure. The aphid's mouthpart has most likely penetrated the plant's: A. xylem B. pollen C. stomata D. shoot system

B. pollen

A sample of pure water is analyzed for the atoms present. Which of the following would be the correct percentages of atoms present in the sample? A. 50.0 percent oxygen, 50.0 percent hydrogen B. 66.6 percent oxygen, 33.3 percent hydrogen C. 33.3 percent oxygen, 66.6 percent hydrogen D. 25.0 percent oxygen, 75.0 percent hydrogen

C. 33.3 percent oxygen, 66.6 percent hydrogen

Which of the following statements is a basic summary of one of Mendel's laws: A. All beneficial human genetic traits are dominant, and harmful traits are recessive. B. The pattern of inherited characteristics of organisms is not predictable. C. The separation of alleles for one gene does not affect the separation of alleles for other genes. D. Recessive alleles cause the death of a gamete.

C. The separation of alleles for one gene does not affect the separation of alleles for other genes.

Two populations of lizards live in the same area. Which of the following evidence would convince you that they are two distinct species? A. Individuals in one population display a different color pattern than individuals in the second population. B. Individuals in one population are noticeably larger than individuals in the second population. C. The two populations are not capable of interbreeding and producing fertile offspring. D. The two populations are capable of interbreeding and producing fertile hybrid offspring.

C. The two populations are not capable of interbreeding and producing fertile offspring.

The information in a gene is encoded by the: A. rRNA that transfers amino acids to ribosomes. B. amino acids that make up the genes. C. base sequences of the gene's DNA. D. introns of eukaryotic cells.

C. base sequences of the gene's DNA.

If follicle-stimulating hormone (FSH) and luteinizing hormone (LH) stimulate the production of sperm and the release of testosterone in males in a homeostatic negative feedback loop pathway, an increase in which of the following hormones might inhibit the production of sperm? A. FSH and LH B. FSH C. testosterone D. LH

C. testosterone

Dolphin embryos develop hind limb buds, but these buds disappear after a short time. What is one mechanism to explain how this change occurs in the embryo? A. The dolphin does not have the gene for the production of hind limbs. B. The hind limbs are not adaptive, and dolphins with hind limbs do not survive as well. C. The hind limbs are not used and atrophy. D. Genes that control the development of the embryo turn off the development of the hind limb.

D. Genes that control the development of the embryo turn off the development of the hind limb.

A solution with a pH of 4 is __________ acidic than a solution with a pH of 5. The solution with the pH of 4 has a __________ concentration of hydrogen ions than the solution with a pH of 5 A. less; lower B. less; higher C. more; lower D. more; higher

D. more; higher

In the reaction H2O + CO2 + carbonic anhydrase > H+ + HCO3-+ carbonic anhydrase, carbonic anhydrase is a(n): A. reactant B. product C. enzyme D. active cite

c. enzyme

A rapidly dividing cell is exposed to a chemical that converts the bond that forms between adenine and thymine to a stronger covalent bond. Which of the following is most likely to occur? A. DNA replication would not occur because the two nucleotide strands that make up the DNA molecule would not be able to separate. B. DNA replication would be faster because covalent bonds require less energy to break than hydrogen bonds. C. DNA replication would occur more slowly because DNA repair proteins would have to fix the covalent bonds before replication could begin. D. DNA replication would produce two molecules of DNA with mutations at every base that once held an A-T base pair.

A. DNA replication would not occur because the two nucleotide strands that make up the DNA molecule would not be able to separate.

In light of the out-of-Africa hypothesis, which of the following is a probable reason why species such as Homo neanderthalensis, Homo floresinensis, and Homo erectus do not exist today? A. Modern Homo sapiens outcompeted and replaced other hominin species as they migrated around the world. B. Climate change in Africa caused the extinction of all hominin populations except the ones that gave rise to modern Homo sapiens. C. Extensive gene flow between human populations led to a blending of traits that resulted in the evolution of Homo sapiens. D. As modern Homo sapiens developed new and more accurate hunting skills, they were able to hunt other hominin species to extinction.

A. Modern Homo sapiens outcompeted and replaced other hominin species as they migrated around the world.

Which of the following statements about bird evolution is NOT correct? A. Scientific studies have revealed so many errors in the traditional dinosaur-bird evolutionary tree that none of it is considered useful to understanding the evolution of birds and flight. B. Scientific comparisons of Archaeopteryx and Xiaotingia fossils caused scientists to adjust the traditional dinosaur-bird evolutionary tree. C. Scientific studies of the Xiaotingia fossil caused scientists to adjust the traditional dinosaur-bird evolutionary tree. D. It is important to understand the dinosaur-bird evolutionary tree in order to have a better understanding of how flight evolved.

A. Scientific studies have revealed so many errors in the traditional dinosaur-bird evolutionary tree that none of it is considered useful to understanding the evolution of birds and flight.

Astronauts returning from outer space studied samples taken from their lunar landing. They found that one of their samples was coated with organic compounds. Which of the following statements must be correct? A. The samples must contain carbon atoms. B. The specimen must lack water, pesticides, and added hormones. C. The compounds must be covered with ammonia (NH3) and water vapor. D. The samples must lack water but contain DNA.

A. The samples must contain carbon atoms.

Consider that fossils of Homo erectus dating between 1.66 and 1.85 mya have been found scattered across Eastern Europe and through China and Southeast Asia and dating back to 2.4 mya in Africa. The earliest known specimens of anatomically modern Homo sapiens in Africa date back to roughly 200,000 years ago and 40,000 to 60,000 years ago across Europe and Asia, with some dated to 115,000 years ago in India. Additionally, Homo neanderthalensis was present across Europe by 150,000 years ago and then spread into western Asia. Concerning the out-of-Africa hypothesis, this suggests that: A. hominins migrated north from Africa, spreading out across Europe and Asia at least twice. B. there was only one major migration of hominins out of Africa. C. hominins migrated north from Africa, spreading out across Europe and Asia three times. D. there must have been at least seven major migrations of hominins out of Africa.

A. hominins migrated north from Africa, spreading out across Europe and Asia at least twice.

Anthers are typically attached to filaments and elevated within the flower to: A. improve the transfer of pollen to a pollinator. B. improve the transfer of pollen to the adjacent ovary. C. prevent pollen from becoming stuck in the nectar. D. prevent pollen from being blown away from the flower.

A. improve the transfer of pollen to a pollinator.

Hypotheses can be tested through observational studies or experimental studies. Which of the following represents an experimental approach to testing a hypothesis? A. injecting trees with insecticide to determine whether it protects against a certain insect pest B. searching for fossils in a recently exposed outcropping of rock C. predicting migration routes for monarch butterflies in light of anticipated future climate change D. measuring crop yields to better document the impacts of a severe drought

A. injecting trees with insecticide to determine whether it protects against a certain insect pest

If the mitochondria of a cell did not produce an inner membrane, the mitochondria would be unable to: A. maintain the proton gradient required for ATP production. B. capture ATP from the sun. C. perform catabolic reactions. D. perform glycolysis.

A. maintain the proton gradient required for ATP production.

Based upon the evolutionary traits visible in blooming rose bushes in a garden, a reasonable deduction would be that the: A. presence of flowers means they are angiosperms. B. lack of an extensive vascular system means they are bryophytes. C. presence of seeds means they are gymnosperms. D. lack of visible fruit means they are ferns.

A. presence of flowers means they are angiosperms.

Prokaryotes lack membrane-enclosed organelles and thus do not have nuclei. Therefore, prokaryotic: A. transcription and translation both take place in the cytoplasm. B. cells do not need to undergo transcription. C. cells do not need to undergo translation. D. cells are unable to undergo transcription and translation.

A. transcription and translation both take place in the cytoplasm.

The coat color in a Siamese cat is determined by a temperature-sensitive allele that allows the pigment melanin to be produced in extremities of the body. What might explain this phenomenon A. Melanin appears darker in extremities because less light is reflected. B. Alleles produce proteins that function best in specific temperature ranges. C. Siamese cats evolved in warm climates and did not need melanin. D. Extremities in a cat are more prone to damage from sunlight.

B. Alleles produce proteins that function best in specific temperature ranges.

When making sourdough bread, bakers use a combination of microorganisms to produce the sour flavor and to leaven the dough before baking. The organisms typically used to produce the lactic acid that give sourdough its distinctive flavor are very small rod-shaped prokaryotic organisms known generally as Lactobacilli. These microorganisms are from the kingdom __________. The other organisms that produce the leavening effect are nonphotosynthetic eukaryotes, have cell walls, absorb their nutrients from their environment, and (in this case) are very tolerant of acidic environments. These microorganisms are from the kingdom __________ A. Plantae; Bacteria B. Bacteria; Fungi C. Plantae; Fungi D. Animalia; Bacteria

B. Bacteria; Fungi

Scientists use existing fossils to predict what the transitional forms between organisms might look like. Why might it be so hard for scientists to find fossils of these transitional forms? A. Scientists have no way to determine how deep in a rock to look for a transitional fossil, so they just have to dig and dig until they find the right fossil. B. Fossils of transitional species may have never formed due to environmental conditions, or if they did form, natural processes like erosion may have destroyed them. C. Because of continental drift, the exact location of where a transitional fossil should be found cannot be determined. Looking for a particular fossil that could be anywhere on the planet is like looking for a needle in a haystack. D. The transitional form of any organism is only hypothetical in nature; it never truly existed on the planet and, therefore, could never become a fossil.

B. Fossils of transitional species may have never formed due to environmental conditions, or if they did form, natural processes like erosion may have destroyed them.

Two organisms that are true-breeding for a certain genetic characteristic are mated and their offspring analyzed. Which of the following statements about this situation is true? A. Both parents are heterozygotes. B. The offspring are either 100 percent homozygotes or 100 percent heterozygotes. C. The offspring represent the P generation. D. The gametes produced by the offspring will carry two alleles for this gene.

B. The offspring are either 100 percent homozygotes or 100 percent heterozygotes.

The polymerase chain reaction (PCR) technique could be developed only after the discovery of bacterial enzymes that were able to withstand high temperatures. Why was it necessary to use such enzymes? A. Bacterial enzymes can bind to DNA outside of a cell. B. The temperature required to separate DNA strands during PCR degrades other enzymes. C. DNA can be cut into fragments only at high temperatures. D. Only bacterial DNA can be copied using the PCR method, so bacterial enzymes were necessary.

B. The temperature required to separate DNA strands during PCR degrades other enzymes.

Why would hydrophilic substances such as sodium ions (Na+), hydrogen ions (H+), sugars, and amino acids be unable to simply diffuse across a plasma membrane? A. They do not readily mix with the hydrophobic tails forming the core of the phospholipid bilayer; therefore, the only way they can move into the cell is by endocytosis. B. They do not readily mix with the hydrophobic tails forming the core of the phospholipid bilayer; therefore, they must move across by facilitated diffusion. C. They are repelled by the hydrophilic heads of the phospholipids that form the phospholipid bilayer. D. They readily mix with the hydrophobic tails that form the core of the phospholipid bilayer.

B. They do not readily mix with the hydrophobic tails forming the core of the phospholipid bilayer; therefore, they must move across by facilitated diffusion.

In the late spring, Miles moves into a new house with a small tree growing in the yard. The flowers on this tree have five white petals tinged with pink. Later in the summer, he notices a small fruit where each of the flowers had bloomed. Miles does not take long to realize this is an apple tree, Malus pumila. This apple tree is a(n) __________ from kingdom Plantae A. bryophyte B. angiosperm C. gymnosperm D. cycad

B. angiosperm

Basil will produce tiny flowers if it is not kept trimmed back. After these tiny flowers are pollinated, they produce tiny seeds encased in a papery covering. Basil is an example of a(n): A. fungus. B. angiosperm. C. gymnosperm. D. bryophyte.

B. angiosperm.

Therapeutic touch (TT) is a type of "energy" medicine that involves the practitioner moving his or her hands over the energy field of the patient, without actually touching the patient, to redirect the energy field and heal the patient. Which of the following would be the first concept to investigate to help evaluate the claims of TT practitioners: A. documentable and repeatable evidence that TT practitioners can, without seeing or touching their subjects, actually feel the energy field of a patient B. documentable and repeatable evidence that an external energy field actually exists for humans C. documentable claims by TT practitioners and their patients that the patients thought they felt better after being treated by the TT practitioner even though there was no change in their diseases D. documentable and repeatable evidence that any existing energy field can be manipulated by merely passing hands over it

B. documentable and repeatable evidence that an external energy field actually exists for humans

The organism Entamoeba histolytica is one of the causes of amoebic dysentery. Infection occurs when cysts of this organism are swallowed and enter the patient's digestive tract. These cysts each have four nuclei, and once in the digestive tract the cysts divide into four cells, each with its own nucleus. Each new cell can invade the mucosal lining of the digestive tract by pushing its pseudopodia into the lining. This organism is a __________ that belongs to the __________ A. eukaryote; domain Bacteria B. eukaryote; group protists C. prokaryote; domain Bacteria D. prokaryote; group protists

B. eukaryote; group protists

Some finches on the Galápagos Islands eat insects, an unusual food for finches to eat. These finches: A. learned their habits from local birds. B. fill roles that birds other than finches would fill in other places. C. switched to insects because they tasted better than their usual food. D. evolved from a lineage of birds other than finches that ate insects.

B. fill roles that birds other than finches would fill in other places.

Pignoli are pine nuts that have lent themselves to culinary uses as far back as the Roman Empire. Pignoli are "naked seeds" harvested from the scales of the cones produced by the Italian Stone Pine tree. The Italian Stone Pine and other pine nut-producing trees are __________ from kingdom Plantae A. bryophytes B. gymnosperms C. angiosperms D. cycads

B. gymnosperms

Dialysis tubing is a selectively permeable membrane that can be filled with a solution to simulate a cell. A piece of dialysis tubing has been filled with a cloudy white solution of 5 percent starch, 5 percent egg albumin (protein), and 5 percent glucose (a small sugar) dissolved in water to simulate a cell. This simulated cell is weighed and then placed in a beaker of pure water. After soaking in the beaker solution for one hour, the simulated cell is once again weighed. Over time, the weight of the simulated cell can be expected to? A. decrease because the cell is hypertonic to the beaker solution and water will leave the simulated cell through osmosis. B. increase because the solution in the beaker is hypotonic to the simulated cell and water will enter the simulated cell through osmosis. C. increase because the cell is hypotonic to the beaker solution and water will enter the simulated cell through osmosis. D. decrease because the solution in the beaker is hypertonic to the simulated cell and water will leave the simulated cell through osmosis.

B. increase because the solution in the beaker is hypotonic to the simulated cell and water will enter the simulated cell through osmosis.

Neighboring water molecules are held together with hydrogen bonds because: A. ionic interactions repel water molecules from hydrophobic oils that may be present in a solution. B. partially negatively charged oxygen atoms and partially positively charged hydrogen atoms on separate water molecules are attracted to one another. C. the hydrogen and oxygen atoms within a single water molecule share electrons equally. D. the oxygen and hydrogen atoms that participate in hydrogen bonding share electrons within a single valence shell.

B. partially negatively charged oxygen atoms and partially positively charged hydrogen atoms on separate water molecules are attracted to one another.

In bacteria, the antibiotic tetracycline blocks the site where tRNA molecules enter the ribosome. The most likely reason that bacteria die from treatment with tetracycline is because the antibiotic: A. inhibits the cell from producing the mRNA. B. prevents the bacteria from assembling essential proteins. C. causes tRNA rather than mRNA to be made into proteins. D. causes the tRNA molecules to randomly arrange into proteins that do not function.

B. prevents the bacteria from assembling essential proteins.

Mendel's manuscript discussing his pea-breeding results is considered one of the two most important scientific papers of the nineteenth century because he was the first to explain how: A. mutations produced the variety of alleles displayed by individuals of the same species. B. traits are passed from one generation to the next. C. meiosis controls the distribution of alleles to each gamete. D. genes are arranged on chromosomes in the cell.

B. traits are passed from one generation to the next.

Why might many new species form in the aftermath of a mass extinction? A. Gene flow among the remaining species would be increased, giving rise to many new genetic re-combinations. B. New environments would increase mutation rates. C. Changed environments and reduced competition would provide opportunities for new adaptations. D. Populations of remaining species would expand rapidly and reduce geographic isolation.

C. Changed environments and reduced competition would provide opportunities for new adaptations.

When researchers found a fossilized jawbone from a late (about 43,000-45,000 years ago) Italian Neanderthal, they noted that the shape of the jawbone suggested that the individual had an intermediate chin instead of no chin like most Neanderthals. This would provide evidence supporting which of the following hypotheses A. Homo habilis and Homo neanderthalensis successfully bred with each other while they were present on the Italian peninsula of Europe. B. Homo habilis and Homo neanderthalensis successfully bred with each other while they were present in central Africa. C. Modern Homo sapiens and Homo neanderthalensis successfully bred with each other while they were present on the Italian peninsula of Europe. D. Modern Homo sapiens and Homo neanderthalensis successfully bred with each other while they were present in central Africa.

C. Modern Homo sapiens and Homo neanderthalensis successfully bred with each other while they were present on the Italian peninsula of Europe.

A mutation in a gene produces the identical protein to the original gene and, therefore, an identical trait. Will evolution act upon this mutation? A. Yes, because mutations contribute to evolution. B. No, because mutations do not contribute to evolution. C. No, because evolution acts upon phenotypes. D. Yes, because evolution acts upon phenotypes.

C. No, because evolution acts upon phenotypes.

A fisherman catches and removes one trout from each of two ponds. Pond A contains 100 trout and pond B contains 1,000 trout. Which population is more affected by the fisherman? A. Pond B; the fisherman is more likely to catch a fish that is undergoing evolution in a bigger population. B. Pond B; the process of evolution occurs more slowly in large populations and removing a fish speeds up the process. C. Pond A; the fisherman has a greater likelihood of completely removing alleles from the gene pool by taking a fish from the smaller population. D. Pond A; fewer fish are able to move into a small pond and find mates.

C. Pond A; the fisherman has a greater likelihood of completely removing alleles from the gene pool by taking a fish from the smaller population.

Plants and animals use different energy storage molecules, yet they both use the same mechanism to metabolize their stored energy. How can plants and animals both be successful, even though they use different energy storage molecules? A. The internal components of plant and animal cells are identical. B. The first law of thermodynamics says that all cells have the same energy transfer system. C. The breaking of chemical bonds in a storage molecule results in the transfer of energy, regardless of the molecule that is stored. D. All organisms have the same enzymes to catalyze their energy-producing reactions.

C. The breaking of chemical bonds in a storage molecule results in the transfer of energy, regardless of the molecule that is stored.

A lizard is attacked by a bird. The lizard escapes and survives without his hind legs. Fortunately for this lizard, the loss of his hind limbs allows him to live within a smaller crevice than other lizards of the same species, so he experiences less competition. Which of the following is true for this lizard? A. A lack of hind limbs should become more common in this population. B. The loss of his hind legs would be considered an adaptive trait. C. The loss of his legs provided an overall advantage within his environment. D. This lizard will be unable to reproduce.

C. The loss of his legs provided an overall advantage within his environment.

If a recessive allele causes a fatal disease that kills the affected individual before he or she can reproduce, why doesn't that allele quickly become extinct in the population: A. The homozygous dominant individuals protect the recessive allele in their genomes. B. The homozygous recessive individuals give their alleles to other individuals before they die from the disease. C. The recessive allele is carried in the genome of heterozygotes, who do not suffer from the disease. D. Alleles are never lost from a population.

C. The recessive allele is carried in the genome of heterozygotes, who do not suffer from the disease.

A research team publishes a study that demonstrates a longer life span for rats fed a low-caloric diet compared to rats with a normal diet. An independent research team repeats the experiment using the same experimental conditions and finds no significant effect of caloric intake on life span. Select the appropriate conclusion for these findings: A. The results of the follow-up study are flawed. B. The results of the first study failed to complete peer-review publication. C. The results of the follow-up study reject the hypothesis. D. The results of the first study are group biased.

C. The results of the follow-up study reject the hypothesis.

A rain forest is a highly complex habitat with organisms living at various levels in the trees, on the ground, and underground. Is it possible to consider two populations of insects living in the same tree to be geographically isolated? A. No, because if they are in the same tree, they are in the same geographic area. B. No, because if they are in the same square acre, they cannot be considered geographically isolated. C. Yes, because there are so many habitats in one tree that the populations may never interact. D. Yes, because insects only undergo allopatric speciation, and there are many species of insects.

C. Yes, because there are so many habitats in one tree that the populations may never interact.

Which of the following prokaryotes would be most likely to survive a full year in a freezing arctic tundra? A. an aerobic bacterium B. a nitrogen-fixing bacterium C. a bacterium capable of sporulation D. an anaerobic bacterium

C. a bacterium capable of sporulation

The processes of mitosis, meiosis, and binary fission all: A. generate offspring cells through asexual reproduction. B. occur in both eukaryotic and prokaryotic cells. C. are used to produce daughter cells. D. generate clones

C. are used to produce daughter cells.

Some organisms switch from male to female or vice versa. The most likely reason for the change is the: A. loss of chromosomes from one year to the next. B. loss of reproductive ability. C. availability of environmental resources. D. ability to reproduce asexually versus sexually.

C. availability of environmental resources.

A researcher is recording the process of bacterial cell division using time-lapse microscopy. Which of the following processes would be observed: A. meiosis B. mitosis C. binary fission D. either meiosis or mitosis, depending on the growth conditions

C. binary fission

The fact that the onset of autism symptoms typically occurs at about the same age children receive many of their vaccinations, including the MMR, is an example of an observed: A. cause-effect relationship but not necessarily a correlation. B. correlation and strong evidence of a cause-effect relationship. C. correlation but not necessarily evidence of a cause-effect relationship. D. cause-effect relationship supported by empirical evidence.

C. correlation but not necessarily evidence of a cause-effect relationship.

It could help meet transplant needs to use a patient's own stem cells to grow a human liver in a pig embryo modified by CRISPR. As an additional and essential step in the process to ensure the liver is safe for the patient, CRISPR should be used to: A. insert human hemoglobin DNA into the pig embryo to make it possible for the growing pig to support the human liver. B. insert human immune cell DNA into the pig embryo to make it more similar to the patient. C. knock out all of the porcine endogenous retrovirus (PERV) genes to prevent infection of the human patient with porcine endogenous retroviruses. D. knock out all of the pig brain genes to prevent the pig brain cells from infecting the patient.

C. knock out all of the porcine endogenous retrovirus (PERV) genes to prevent infection of the human patient with porcine endogenous retroviruses.

For two populations to accumulate enough genetic differences to cause speciation, the factors that promote these differences: A. need to be combined with the forces of genetic drift. B. must operate in populations that are not physically separated. C. must have a greater effect than does the amount of ongoing gene flow. D. should include polyploidy.

C. must have a greater effect than does the amount of ongoing gene flow.

In general, geographical isolation occurs when: A. populations migrate to new environments. B. gene flow is reduced by more than 75 percent due to climate change. C. populations are separated by a distance or land formation that is great enough to limit gene flow. D. mutations overcome genetic drift across physical barriers.

C. populations are separated by a distance or land formation that is great enough to limit gene flow.

As Charlotte snorkels near the shoreline, she notices large masses of something green swaying with the surf. She suspects this to be a large plant in the ocean. She collects a sample. Upon closer examination, she discovers that there are no vascular structures to absorb and transport water and nutrients throughout the organism, but there are chloroplasts present in the cells. This organism most likely belongs to: A. kingdom Fungi. B. kingdom Plantae. C. protists. D. kingdom Animalia.

C. protists.

If a female's mitochondrial DNA were sequenced and compared to the sequence of mitochondrial DNA isolated from her mother's paternal grandmother (the mom of her mom's dad), she likely __________be a significant match because __________ A. would; a person inherits her mitochondrial DNA from her dad who inherited it from his mom B. would; a person inherits her mitochondrial DNA from her mom who inherited from her dad C. would not; a person's mitochondrial DNA is inherited from her mom who inherited it from her mom D. would not; a person's mitochondrial DNA is inherited from her dad who inherited it from his mom

C. would not; a person's mitochondrial DNA is inherited from her mom who inherited it from her mom

The faster a cheetah can run, the more likely it is to capture its prey. Cheetahs with longer legs are able to run faster than those with shorter legs. Although the existing cheetah population shows a variety of leg lengths, cheetah legs are not continuing to increase in length from one generation to the next. Which of the following is a possible explanation? A. Natural selection does not act on traits involved in predation. B. Cheetahs with long legs are reproductively isolated from cheetahs with short legs. C. The genes that are involved in cheetah leg length do not undergo mutation. D. Longer cheetah leg bones are more likely to break.

D. Longer cheetah leg bones are more likely to break.

When Lori was diagnosed with breast cancer, the doctor recommended a lumpectomy followed by radiation therapy. Lori underwent the prescribed treatment recommended by the doctor. However, she also continued to eat lots of fruits and vegetables, walk three miles every day, and practice daily yoga. Within about three months, Lori was cancer-free. Afterward, Lori told everyone that her healthy lifestyle had helped to cure her. Is this conclusion reasonable given the circumstances? A. Yes, this evidence very strongly supports the hypothesis that a healthy diet and exercise regimen probably helped to cure her. B. No, a healthy diet and exercise regimen can never help cure cancer. C. Yes, the healthy diet and exercise regimen definitely helped to cure her. D. No, there are too many confounding factors to know exactly what happened.

D. No, there are too many confounding factors to know exactly what happened.

Mass extinctions cause the loss of many species, no matter how well adapted those species were before the extinction. Why might previous adaptations NOT help a species survive a mass extinction? A. Ongoing continental drift allows more species to interbreed, which lowers the genetic variability available for adaptation. B. Adaptive radiations are stronger than adaptations. C. Well-adapted organisms will not be affected by mass extinction; these are the groups that will survive. D. The rapid environmental changes that cause mass extinctions do not leave the organisms time to adapt.

D. The rapid environmental changes that cause mass extinctions do not leave the organisms time to adapt.

Patricia Hunt determined that bisphenol A (BPA) was hindering the process of meiosis in the ovaries of the mice in her experiment. BPA disrupted the ability of the chromosomes to separate into four haploid cells. Which of the following statements describes possible outcome(s) of this disruption: A. All four resulting cells will have exactly half the number of chromosomes found in the parent cell. B. Three of the resulting cells will have exactly half the number of chromosomes found in the parent cell. The fourth cell will have double the chromosome number found in the parent cell. C. Two of the resulting cells will have exactly half the number of chromosomes found in the parent cell. The other two cells will have exactly triple the chromosome number found in the parent cell. D. Two of the resulting cells will have exactly half the number of chromosomes found in the parent cell. A third cell will have one more than half and a fourth cell will have one fewer than half the number of chromosomes found in the parent cell.

D. Two of the resulting cells will have exactly half the number of chromosomes found in the parent cell. A third cell will have one more than half and a fourth cell will have one fewer than half the number of chromosomes found in the parent cell.

Before the cultivation of the apple tree, apple maggot flies laid their eggs exclusively on the fruit of Hawthorne trees. As apple orchards became more prominent, apple maggot flies began to lay their eggs on both the fruit of the Hawthorne tree and the fruit of cultivated apple trees. Now, apple maggot flies that live on apple trees mate and lay their eggs at different times of the year than apple maggot flies that live on Hawthorne trees. Is this an example of reproductive isolation? A. Yes; these two fly populations exhibit a postzygotic barrier that prevents hybrid individuals from developing properly. B. No; this is an example of speciation rather than reproductive isolation. C. No; although these two fly populations do not mate in nature, they can be forced to mate in a laboratory because their DNA sequences are still the same. D. Yes; these two fly populations exhibit a behavioral prezygotic barrier that prevents their gametes from encountering each other.

D. Yes; these two fly populations exhibit a behavioral prezygotic barrier that prevents their gametes from encountering each other.

On a hike, Cheryl notices some flat green plants clinging to the side of a damp rock. She brings a few of these flat but leaf-shaped plants back to the lab to examine under the microscope and determines that these plants are only a few cells thick and have no vascular tissues. They appear to be absorbing water directly through their surfaces. These little plants are probably: A. angiosperms. B. gymnosperms. C. aquatic algae. D. bryophytes.

D. bryophytes.

In humans the tRNA with the anticodon AAU carries the amino acid leucine. In plants, this tRNA would: A. not carry an amino acid. B. carry a different amino acid. C. not have an anticodon. D. carry the same amino acid.

D. carry the same amino acid.

You are given an unknown substance and asked to determine whether it is polar or nonpolar. The easiest way to do this would be to: A. mix the compound with an ionic substance to see whether its bonds can withstand the pressure. B. determine whether the compound is held together by hydrogen bonds. C. determine the number of electrons in the compound's outer shell. D. determine whether the compound dissolves in water.

D. determine whether the compound dissolves in water.

The infamous American outlaw Jesse Woodson James died April 3, 1882. His body was originally interred on the James's farm but was later moved to Mt. Olivet Cemetery in Kearney, Nebraska. Some people have hypothesized that his death was staged. Researchers have exhumed the body and analyzed mitochondrial DNA found in the teeth with that of mitochondrial DNA from hair samples from the burial site on the James farm—and they matched. These samples were then compared to the mitochondrial DNA of Jesse's sister Susan's great-grandson and her great-great-grandson. The hypothesis that the body buried in Mt. Olivet Cemetery is not Jesse James would be supported if the mitochondrial DNA from the grave: A. matches not only the mitochondrial DNA obtained from Susan's great-grandson and her great-great-grandson but also the mitochondrial DNA from Susan's daughter. B. matches the mitochondrial DNA obtained from Susan's great-grandson and great-great-grandson. C. matches Susan's mitochondrial DNA. D. does not match the mitochondrial DNA obtained from Susan's great-grandson and great-great-grandson.

D. does not match the mitochondrial DNA obtained from Susan's great-grandson and great-great-grandson.

DNA from a fossil is found, and it is hypothesized that the mother was a Neanderthal and the father was a human. Which of the following would support this hypothesis? A. finding discernible amounts of nuclear Neanderthal and human DNA but no mitochondrial Neanderthal DNA B. finding significant amounts of human mitochondrial and nuclear DNA along with some nuclear Neanderthal DNA C. finding all the nuclear DNA to be Neanderthal and all the mitochondrial DNA to be human D. finding discernible amounts of mitochondrial and nuclear Neanderthal DNA along with nuclear human DNA

D. finding discernible amounts of mitochondrial and nuclear Neanderthal DNA along with nuclear human DNA

Although it seems contradictory, real science does not intend to "prove" a hypothesis to be true. This is because: A. all true hypotheses will be rejected by the scientific method because they can be proven false. B. science is a human endeavor, and like all human endeavors, it is limited by human understanding. C. the scientific method is limited to examination of the natural world. D. future experiments or discoveries may provide data that refute the hypothesis.

D. future experiments or discoveries may provide data that refute the hypothesis.

A patient often experiences numbness and pain in the thumb and first two fingers on his right hand. He goes to his doctor, who suspects that carpal tunnel syndrome is the reason for the numbness and pain. The doctor then orders a simple test to see how fast nerve impulses move up and down the patient's arm. The doctor's preliminary diagnosis of carpal tunnel syndrome is a(n)? A. facts B. theory C. experiment D. hypothesis

D. hypothesis

A scientist has assembled 1.0 gram of protein, lipid, carbohydrate, and nucleic acids in separate tubes. They add each of these samples to a calorimeter, a device that determines the amount of energy present in the sample. Based on the role of these molecules in the body, predict which test tube will produce the most energy A. carbohydrates B. proteins C. nucleic acids D. lipids

D. lipids

Liposomes form spontaneously from __________ and are important because __________ A. DNA; they provide a rigid structure to support the cell B. phospholipid monolayers; these phospholipid monolayers provide a stable barrier between the internal and external environments C. rigid cell walls; they provide support for the living cell and a barrier between the external and internal environments D. phospholipids and water; they provide a barrier between an external environment and an internal environment

D. phospholipids and water; they provide a barrier between an external environment and an internal environment

One of the earliest prokaryotes on Earth, the cyanobacteria, played an important role in the evolution of multicellular eukaryotes. These early prokaryotes changed Earth's chemistry when they began: A. existing in oxygen-free environments. B. capturing energy from inorganic iron ore. C. recycling nutrients locked in organic matter. D. producing oxygen as a by-product of photosynthesis.

D. producing oxygen as a by-product of photosynthesis.

It is particularly important for pregnant women to carefully wash their hands and take other precautions if they have a pet cat and are changing the litter box. An organism occasionally carried by cats, pigs, and sheep can infect humans and pass from mother to child in utero, resulting in severe symptoms in the growing child. Microscopic examination of this single-celled organism shows a nucleus and other visible cellular organelles. This pathogenic organism is the: A. protist Plasmodium vivax. B. bacterium Toxoplasma gondii. C. bacterium Plasmodium vivax. D. protist Toxoplama gondii.

D. protist Toxoplama gondii.

The energy carriers NADPH and NADH differ structurally. Functionally they are: A. quite similar; each is produced in catabolic pathways and used in anabolic pathways. B. quite similar; each is produced in anabolic pathways and used in catabolic pathways. C. somewhat different; NADPH is produced from catabolic processes, whereas NADH is used in anabolic processes. D. somewhat different; NADH is produced from catabolic processes, whereas NADPH is used in anabolic processes.

D. somewhat different; NADH is produced from catabolic processes, whereas NADPH is used in anabolic processes.

Most plants have indeterminate growth. This means that plant growth can respond to environmental conditions and that: A. they are perennials. B. they may complete their life cycles in one, two, or three years. C. they reach maturity at variable times based on external signals. D. the final form of the plant is not entirely predictable.

D. the final form of the plant is not entirely predictable.

Fiddlehead greens are the curled, young fronds of a fern. Harvested very early and trimmed close to the ground, they provide a tasty addition to salads. These multicellular, photosynthetic, vascularized organisms that do not produce seeds belong to: A. protists. B. the domain Archaea. C. the kingdom Fungi. D. the kingdom Plantae.

D. the kingdom Plantae.

Which of the following statements about sexual reproduction in humans is true? A. Both parents contribute genes to the offspring. B. The offspring are identical to their parents. C. Only one parent contributes genes to the offspring. D. Only one parent is needed to produce offspring.

A. Both parents contribute genes to the offspring.

What information cannot be determined by a karyotype? A. allele versions B. the number of autosomes C. the individual's sex D. chromosomal deletions

A. allele versions

A worker is paid every two weeks. She uses some of this money to pay for essentials and puts the remainder of her money in a savings account at a bank. The money the worker saves is analogous to the: A. conversion of ADP and free phosphate into ATP. B. conversion of ATP into ADP and free phosphate. C. way electrons are used to pump protons across a membrane D. way enzymes catalyze chemical reactions in a cell.

A. conversion of ADP and free phosphate into ATP.

The number of chromosomes in secondary spermatocytes is fewer than in primary spermatocytes because __________ are separated during meiosis __________ A. homologous pairs; I B. sister chromatids; I C. homologous pairs; II D. sister chromatids; II

A. homologous pairs; I

Which is the most dominant and diverse plant group on Earth? A. gymnosperms B. angiosperms C. ferns D. bryophytes

B. angiosperms

Asexual and sexual reproduction in animals is similar in that both: A. increase genetic variation in the offspring. B. generate offspring that carry parental genes. C. rely on parental chromosomes to mix in new ways. D. produce offspring that have double the amount of genetic information of the parent(s).

B. generate offspring that carry parental genes.

Horticulturists often remove the anthers from flowers. The purpose of this technique is to: A. promote branching B. prevent self-fertilization C. increase egg production. D. attract pollinators.

B. prevent self-fertilization

Which of the following must occur for a mismatch error to be repaired? A. DNA-eating enzymes within the nucleus destroy entire strands of damaged DNA. B. The sequence of nucleotides in the damaged DNA sequence guides the synthesis of the correct DNA sequence. C. DNA repair proteins identify damaged DNA. D. The damaged DNA undergoes DNA replication one more time.

C. DNA repair proteins identify damaged DNA.

Which of the following would explain two chromosomes in an individual cell that contain some, but not all, of the same genes at the same loci: A. Both of the chromosomes are maternal. B. Both of the chromosomes are paternal. C. The chromosomes are from a common ancestor. D. A chromosomal alteration has occurred.

D. A chromosomal alteration has occurred.

A scientist notices that a population of birds has decreased dramatically within one year and suspects that a newly introduced snail population may be affecting the bird population. Some individuals within the bird population eat snails primarily, while other individuals avoid eating snails. Which of the following statements represents a prediction based on a well-constructed hypothesis for this observation? A. If birds consume snails, then they will have a higher body mass index than birds that do not eat snails. B. If snails that are sick leave their shells, which allows birds to consume them, then snail populations will be protected from illness. C. If snails live in moist habitats, then snails will be eaten more frequently by birds. D. If the birds are affected by eating snails, then there will be a difference in the survival rate of birds that eat snails and those that avoid snails.

D. If the birds are affected by eating snails, then there will be a difference in the survival rate of birds that eat snails and those that avoid snails.