Biology Final exam

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.6. What is the percentage of the population that is homozygous for this allele?

40.0

In gene expression, the enzyme ________________ transcribes a copy of a gene into a ______________ molecule, and then this molecule is translated by a __________________________.

RNA polymerase, DNA, ribosome

The predatory fish rely on visual cues and speed to capture mosquitofish. Mosquitofish rely on speed and visual cues to avoid the predatory fish. Which adaptation(s) might help the predators survive in ponds that are home to faster mosquitofish? 1. directional selection for increased speed 2. stabilizing selection for speed that matches that of the mosquitofish 3. change in hunting behavior that replaces reliance on visual cues with reliance on tactile cues, which can be used to hunt at night 4. change in hunting behavior that eliminates speed in favor of better camouflage, which permits an ambush strategy 1 only 2 only either 1 or 3 1, 3, or 4

1, 3, or 4

The diploid chromosome number of an organism is usually represented as 2n. Humans have a diploid chromosome number of 46. What would be the expected haploid chromosome number in a human?

23

Which two of the following have operated in the past to increase divergence between mosquitofish populations on Andros? 1. improved gene flow 2. bottleneck effect 3. sexual selection 4. natural selection 3 and 4 2 and 3 4 only 1 and 3

3 and 4

In this very large population which is not receiving immigrants, a quantitative trait has the following distribution pattern: If the curve in the figure above becomes more narrow, but does not shift to the left or to the right, which of the following is (are) probably occurring?1. gene flow2. directional selection3. adaptation4. genetic drift5. stabilizing selection 1 only 3 and 5 1, 2, and 3 2 and 3

3 and 5

Approximately how far back in time does the fossil record of living organisms extend? 5.0 million years 3.5 million years 3.5 billion years 5.0 billion years

3.5 billion years

In a population of 100 individuals, where a gene exhibits two alleles M and N, 49% are of the NN genotype . What percentage is expected to be MN assuming Hardy—Weinberg equilibrium conditions? 51% 42% 21% 9% There is insufficient information to answer this question.

51%

In the Blackboard learning module "Great Transitions", you learned that humans and modern chimpanzees shared a common ancestor approximately 7MYA 3MYA 1MYA Humans and modern chimpanzees do not share a common ancestor.

7MYA

In the video "Your Inner Monkey", you learned about the transition in the hominid lineage, from a tree-dwelling ape ancestor to a fully bipedal ape-like hominid. When proposing an evolutionary transition, biologists hypothesize about what intermediate traits the transitional organisms must possess. The fossil species proposed as being transitional at this time point was Ardipithecus ramidus. What traits suggest that this species is the correct choice? Homo erectus lived 1 million years ago, which is the time proposed for the transition. It had short broad hipbones and long legs, indicating it could walk bipedally, but still retained long arms, which are ape-like. It was a a hominid with a small brain that was adapted for living in the mountains. Ardipithecus lived 4.4 million years ago, which is the time proposed for the transition. It had short broad hipbones, indicating it could walk bipedally, but still retained a grasping big toe and long fingers, which are ape-like. It was a mosaic of traits, which suggested it could move on on all fours amid tree branches, but walk upright when it came down to the ground. Dryopithecus lived 30 million years ago, which is the time proposed for the transition. It had a short lumbar back, indicating it could walk bipedally, but still retained long curved fingers, which are ape-like. It was a mosaic of traits, which suggested it could pursue a suspensory lifestyle in the trees, but walk upright when it came down to the ground. Aegyptopithecus lived 40 million years ago, which is the time proposed for the transition. It was a cat-sized ape with long hipbones, indicating it could walk quadripedally, but had a brain almost as big as a human's.

Ardipithecus lived 4.4 million years ago, which is the time proposed for the transition. It had short broad hipbones, indicating it could walk bipedally, but still retained a grasping big toe and long fingers, which are ape-like. It was a mosaic of traits, which suggested it could move on on all fours amid tree branches, but walk upright when it came down to the ground.

Consider the figure below. Which part of the brain is involved in information processing and reasoning?

Cerebrum

Which of the following is true for the trait of living in social groups? Costs of living in social groups are increased transmission of parasites and increased food competition, but benefits are increased likelihood of finding food, coupled with reduced likelihood of being preyed upon. A cost of living in a social group is decreased predation risk. A cost of living in social groups is increased transmission of parasites, but a benefit is increased food competition. Living in a social group cannot be costly, otherwise sociality would never have evolved.

Costs of living in social groups are increased transmission of parasites and increased food competition, but benefits are increased likelihood of finding food, coupled with reduced likelihood of being preyed upon.

A deletion mutation within the first exon of the gene is unlikely to influence the phenotype of the mutant.

False

Bipedalism evolved in the hominid lineage before a big brain evolved.

False

In the learning module "Things You May Not Know About Evolution", you learned that bacteria, plants and humans do not share any similar DNA sequences, because the do not share common ancestry.

False

If a speciation event occurred on Sao Tomé, where island D. santomea diverged from an island colony of D. yakuba, then which terms apply? I. genetic differentiation II allopatric speciation III. sympatric speciation

I and III

We have discussed the evolution of whales in many chapters. How many of the following statements concerning the loss of hind limbs during whale evolution are true? 1. It is well documented by a series of transitional fossils. 2. It explains why modern whales have vestigial pelvic girdles. 3. It involved changes in the sequence or expression of Hox genes. 4. It is an example of adaptation to the environment. Only one statement is true. Two statements are true. Three statements are true. Four statements are true.

Four statements are true.

With which of the following statements would a biologist be most inclined to agree? Humans and apes represent divergent lines of evolution from a common ancestor. Humans evolved from chimpanzees. Humans and apes are the result of disruptive selection in a species of chimpanzee. Humans represent the pinnacle of evolution and have escaped from being affected by natural selection.

Humans and apes represent divergent lines of evolution from a common ancestor.

What is true of the fossil record of mammalian origins? It shows that mammals and birds evolved from the same kind of dinosaur. It includes transitional forms with progressively specialized teeth. It includes a series that shows the gradual change of scales into fur. It is a good example of punctuated equilibrium. It indicates that mammals and dinosaurs did not overlap in geologic time.

It includes transitional forms with progressively specialized teeth.

Which of the following statements about evolution of behavior is correct? Instinctive behaviors can never be altered by natural selection. If a behavior is less than optimal, it will eventually become perfectly optimal through natural selection. Natural selection will favor behavior that enhances survival and reproduction. All of the statements are correct.

Natural selection will favor behavior that enhances survival and reproduction.

Co-evolution of host plant and animal pollinators is common. The host plants needs the animal to nestle deeply into the flower to get covered with pollen to carry to other flowers, but the animal benefits from quickly sipping nectar and then leaving. The graph below illustrates the relationship between traits important for this relationship: flower depth and tongue length for two species of fly pollinators. What can you infer from these data ? Table https://gyazo.com/ea33cc310e0f853719d7d66e3311a078 Fly tongue length cannot co-evolve with plant flower shape, because these are traits found in two different species. There is no clear co-evolutionary relationship between fly tongue length and flower depth. Plants constantly evolve more shallow flowers to force flies to nestle into the flower, but flies adapt by evolving shorter tongues so they can sip and fly away. Plants constantly evolve deeper flowers to force flies to nestle into the flower, but flies adapt by evolving longer tongues so they can sip and fly away.

Plants constantly evolve deeper flowers to force flies to nestle into the flower, but flies adapt by evolving longer tongues so they can sip and fly away.

Which of these evolutionary trees represents the situation described here ( Note: Yakuba ( I) represents the island population, and yakuba ( M) represents the mainland population)?

Santomea (longest line), yakua (I) (shortest line), yakuba (M) (no line); straight line that extends up and to the right

In the online learning module "Evolution in action: Salamanders", you learned that California salamander populations may look very different, even though they are not yet different species. This can be explained by their evolutionary history, in which Central Valley populations adapted to live in ground squirrel burrows. Northern forest populations moved south, but stayed in forested mountain areas on the coast and in the Sierra Nevada mountains, avoiding the Central Valley. Southern populations evolved to live in deserts, but Norther populations evolved to live in forests. Central Valley and coastal populations adapted to different amounts of sunlight.

Southern populations evolved to live in deserts, but Norther populations evolved to live in forests.

When male horses (stallions) and female donkeys (jennets) mate, they produce a sterile hybrid called a hinny. Hinnies occur much less frequently than do mules, but are just as healthy and robust as mules. Logically, which of the following best accounts for the relative rarity of hinnies, and what kind of prezygotic isolating mechanism is at work here? Most hinnies die during fetal development; reduced hybrid viability. Stallions and jennets are choosier about their mating partners than are mares and jacks; behavioral isolation. Stallions and jennets are choosier about their mating partners than are mares and jacks; gametic isolation. Most hinnies are reproductively sterile; reduced hybrid fertility.

Stallions and jennets are choosier about their mating partners than are mares and jacks; behavioral isolation.

Consider the graph below, which plots the parental value for tameness in silver fox against the offspring value for tameness. What do these data suggest?

Tameness is not heritable, because the trait values exhibited by the parents perfectly predict the trait values for the offspring.

An organism has a relatively large number of Hox genes in its genome. Which of the following is true of this organism? Most of its Hox genes owe their existence to gene fusion events. The organism has the genetic potential to have a relatively complex anatomy. The organism must have multiple paired appendages along the length of its body. These genes are fundamental, and are expressed in all cells of the organism. Its Hox genes cooperate to bring about sexual maturity at the proper stage of development.

The organism has the genetic potential to have a relatively complex anatomy.

In the video "Your Inner Monkey", you learned that most mammals have clawed digits that point the same way, like a squirrel. Primates are unique in the possession of longer fingers and an opposable thumb, and nails instead of claws. These traits were exhibited by one of the first primates, Notharctus tenebrosus, which lived 50 million years ago. What is the hypothesized explanation for why the primate lineage evolved these unique traits?

These traits provide the ability to grasp tree branches, specifically the slender terminal branches where high quality foods (such as flowers and fruit) are located.

Which of the following is true of instinctive behaviors? They occur in invertebrates and some vertebrates but not mammals. Their expression is only weakly influenced by genes. They are expressed identically by most individuals in a population, in response to a particular environmental stimulus. They occur in the absence of environmental stimuli.

They are expressed identically by most individuals in a population, in response to a particular environmental stimulus.

"Adaptive radiation" occurs when a few ancestral species undergo an intense period of divergence and speciation . This typically occurs when species adapt to follow new ways of life, and fill previously empty ecological niches (such as when the mammals diversified to fill niches opened when the dinosaurs went extinct).

True

A co-evolutionary relationship may evolve between two species that is mutualistic, yet there still may be a conflict of interest between the species which could drive the evolution of traits associated with their interaction.

True

Animal behaviorists have concluded that all organisms which exhibit complex behavior are intelligent, because complex behavior can only be exhibited by organisms with a central nervous system.

True

In the online learning module "The Nurture of Nature", you learned that mating behavior in vole species is influenced by a hormone receptorgene, and by a second regulatory gene. Prairie voles are monogamous, and montane voles are polygynous. The regulatory gene sequence is longer in the prairie vole. When scientists transferred the full prairie vole gene for the hormone receptor, including the regulatory sequence, into male montane voles, the males became monogamous.

True

Marsupials evolved in North America and colonized Australia via an Antarctic land bridge approximately 20MYA.

True

In the online learning module "What is a species?", you learned that polar bears and grizzly bears are considered different species, because they live in different places. they never hybridize. they look very different. although they hybridize, genetic evidence indicates that they are genetically distinct.

although they hybridize, genetic evidence indicates that they are genetically distinct.

On the Bahamian island of Andros, mosquitofish populations live in isolated freshwater ponds that were once united. Some ponds have many predators, some have few predators. Predator-rich ponds have mosquitofish that can swim in short, fast bursts. 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; they only want to mate with males that have a swimming physiology like their own. 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? mechanical isolation temporal isolation habitat isolation behavioral isolation

behavioral isolation

The evolution of the animal nervous system involved the recruitment of ancient genes for other functions to form neural synapses. These genes originally coded for proteins involved in

cell signaling

Which of the following was not an underlying factor driving the burst of speciation which occurred in the late Ediacaran and early Cambrian? changing oxygen levelsin the atmoshpere the evolution of genes which code for the embryonic body plan in bisymmetrical animals the evolution of appendages, which allow animals to interact with the environment in a more complex way the evolution of metabolism

changing oxygen levelsin the atmoshpere

The 13 species of Galápagos finch are thought to have arisen by

colonization of the islands by a parental population of South American finches, which later diverged.

Which of the following is most likely to produce a plant population whose members exhibit one of two very different flower shapes? disruptive selection stabilizing selection directional selection artificial selection

disruptive selection

Hox genes encode proteins that are responsible for rate of cell division in bacteria. are found only in plants. encode proteins that act as signaling receptors in the cell. build specific anatomical structures during embryonic development.

encode proteins that act as signaling receptors in the cell.

In the in-class videos "Your Inner Fish" and "Great Transformations", you learned about the first tetrapods to colonize land. Which of the following characteristics did it not possess? an egg encapsulated by a hard shell a lobe-finned fish ancestor forelimbs which could support its weight dependence on water for part of its life cycle

forelimbs which could support its weight

In small isolated populations, gene frequencies can fluctuate as a result of statistical sampling effects. The term that applies to this circumstance is ________. genetic isolation stabilizing selection natural selection genetic drift

genetic drift

On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (both species are diploid, with 4 chromosomes in total). Sao Tomé rose from the Atlantic Ocean about 14 million years ago.Which of the following limits gene flow between the two species on Sao Tomé, despite the existence of hybrids?

hybrid sterility

The the most simple type of centralized nervous system includes a brain and one (or more) nerve cords. In which of the following lineages do we see this trait evolving?

it evolved first in annelids, and was retained in chordates and arthropods

If one builds a canal linking a predator-rich pond to a predator-poor pond, then what type(s) of selection should subsequently be most expected among the mosquitofish in the original predator-rich pond, and what type(s) should be most expected among the mosquitofish in the formerly predator-poor pond? Assume only predators are using the canal. stabilizing selection; directional selection stabilizing selection; stabilizing selection less-intense disruptive selection; more-intense disruptive selection less-intense directional selection; more-intense directional selection

less-intense directional selection; more-intense directional selection

A common method for testing if two species are actually species (rather than two divergent populations of the same species) is to look for hybridization between the two groups; the more hybridization, the more likely they are completely different species. look for where the two groups are distributed biogeograpically; the farther away from each other they live, the more likely they are different species. look for hybridization between the two groups; the more hybridization, the more likely they are different populations of the same species. look for morphological differences between the two groups; the more differences, the more likely they are different species.

look for hybridization between the two groups; the more hybridization, the more likely they are different populations of the same species.

A mass extinction event occurs when _____ of the species on Earth go extinct within a short period of time. less than 50% more than 50% exactly 50% None of the above are true, because mass extinction events are not supported by any evidence.

more than 50%

In the online learning module "The Nurture of Nature", you learned that a gene which influences foraging behavior in fruit flies may also influence human behavior, and may explain why some people experience intermittent esplosive disorder seasonal affective disorder (SAD) senile dementia heart disease

seasonal affective disorder (SAD)

The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of

sympatric speciation.

In the video Why sex?, you learned that mate choice is a type of sexual selection which can favor the evolution of traits in the opposite sex which cause communication to be limited. that improve the fitness of the chosen sex. that are honest signals of genetic quality. that increase aggression toward the choosy sex.

that increase aggression toward the choosy sex.

Although many chimpanzees live in environments containing oil palm nuts, members of only a few populations use stones to crack open the nuts. The likely explanation is that members of different populations differ in manual dexterity. the behavioral difference is caused by genetic differences between populations. members of different populations have different nutritional requirements. the learned behavior of using stones to crack nuts has arisen in only some populations.

the learned behavior of using stones to crack nuts has arisen in only some populations.

In the Blackboard learning module "Great Transitions", you learned that adapations to the pelvis occurred in the hominid lineage, to facilitate bipedalism. Which of the following in not one of these physical changes? the pelvis became broader the pelvic bones shifted to accommodate a longer spine the pelvic bones shifted to accommodate bigger gluteal muscles the pelvis became shorter

the pelvis became broader

Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate?

the postzygotic barrier called hybrid inviability

Radiometric dating involves comparison of the ratio of carbon to nitrogen in plants the ratio of three types of daughter isotopes the ratio of daughter isotopes to parent isotopes the accumulation of the daughter isotope in contrast to surrounding sea levels

the ratio of daughter isotopes to parent isotopes

Fossil evidence indicates that several kinds of flightless dinosaurs possessed feathers. If some of these feather-bearing dinosaurs incubated clutches of eggs in carefully constructed nests, this might be evidence supporting the claim that

their FEATHERS originally served as INSULATION, and only later became flight surfaces.

In the online learning module "Tree Diagrams", you learned that if two modern organisms share a recent common ancestor they should not share any characteristics in common. they must live in the same habitat. they should share more homologous traits than two less closely related organisms. they will not have similar DNA sequences.

they should share more homologous traits than two less closely related organisms.