Biology chapter 13 hw q's

Humans are diploid and have 46 chromosomes (or two sets). How many sets of chromosomes are found in each human gamete? 1 2 3 4 5

1

A particular diploid plant species has 48 chromosomes, or two sets. A mutation occurs and gametes with 48 chromosomes are produced. If self-fertilization occurs, the zygote will have _____ set(s) of chromosomes.

4 -If self-fertilization occurs, and two gametes (each having 48 chromosomes) unite, the zygote will have 96 chromosomes (or 4 sets).

Of the 59 matings in the experimental groups, how many were between like-adapted flies (flies adapted to the same medium)?

42

Environmental change example:

A drought causes a habitat to turn dry and brown

Humans are diploid and have 46 chromosomes. How many chromosomes are found in each human gamete?

23- its half of 46

Natural selection is best described as __________. A. A creative force that efficiently develops the best and simplest solutions for all problems in nature. B. A forward-looking process that anticipates future problems and designs the necessary tools to solve them through mutation. C. A filtering process that fine- tunes the traits of populations by sorting among existing, randomly produced variations. D. A completely random and unpredictable process of change, or evolution

C. A filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations.

Which of the following is a true statement about charles Darwin? A. He was the first to discover that living things can change, or evolve. B. He worked out the principles of population genetics. C. He proposed natural selection as the mechanisms of evolution. D. He based his theory on the inheritance of acquired characteristics.

C. He proposed natural selection as the mechanism of evolution

Mass extinctions create conditions that promote _____.

adaptive radiation

Most polyploid plants arise as a result of _____. self-fertilization a mutation of gamete formation meiosis mitosis hybridization

hybridization -Most polyploid plants are the result of the hybridization of two different parental species.

two key observations underlying natural selection are that memebers of a population vary in their __________ and that all species can produce more offspring that the environment can support.

inherited traits

adaptive radiation

rapid speciation under conditions in which there is little competition

As proposed by Darwin, what sorts of traits are favored by natural selection? A. Any traits that are produced by mutation and can be inherited. B. Traits that reduce the number of offspring an individual produces, thus helping to reduce the struggle for existence in the next generation. C. Traits that reduce the mutation rate and cut down on unnecessary variation within populations. D. Heritable traits that help individuals survive and reproduce more successfully than other in the same population.

D. Heritable traits that help individuals survive and reproduce more successfully than others in the same population.

_____ is the process by which haploid gametes form a diploid zygote.

Fertilization

Selective pressure example:

Green beetles are more visible to birds than brown beetles, so birds eat more green beetles.

The human immune system cannot effectively suppress the HIV virus on its own. What key feature of HIV makes it so hard beat? A. The HIV virus can survive harsh conditions for years as a dormant particle. B. The HIV virus has an extremely high rate of mutation. C. the HIV virus has a special protein coat that protects it from attack by all known human immune defenses. D. The HIV virus replicates its genome with a great deal of precision (i.e. has a low mutation rate)

The HIV virus has san extremely high rate of mutation

This unequal reproduction in a population leads to the gradual accumulation of __________ to the environment

adaptations

Biologists have found more than 500 species of fruit flies on the various Hawaiian islands, all apparently descended from a single ancestor species. When this ancestor colonized the island chain, it found few competitors: Many insect and fly families present in other regions are absent from the isolated Hawaiian Islands. This example illustrates _____. sympatric speciation allopatric speciation temporal isolation adaptive radiation

adaptive radiation

The phrase Darwin used to describe his broad theory of evolution is "descent with _________"

modification

The _____ species concept is the most applicable to classifying species from the fossil record.

morphological

Darwin proposed a mechanism for how evolution occurs, which he called ___________

natural selection

Darwin inferred that those organisms with traits best suited to the environment tend to leave _______ than other members of a population

offspring

Which of these terms applies to an organism with extra sets of chromosomes? monosomy haploid trisomy polyploid diploid

polypoid-Polyploid individuals have more than two complete sets of chromosomes.

Darwin thought that significant evolution was much too slow to be witnessed in a human lifetime. Recent experiments by biologists have _____.

shown that some populations can evolve quite rapidly, with important changes occurring over several generations in the laboratory

biological species concept

species is a population of organisms that under natural conditions are able to mate and produce fertile offspring - doesn't work for asexual organisms, prokaryotes, extinct fossil organisms

The ______ of life arises from the adaptiation of species to different habitats over long spans of time.

Diversity

Imagine that four people are infected with HIV from a common source (an infected blood sample). Initially, the patients' HIV populations are genetically identical. By the time they develop full-blown AIDS, how would the viral populations of the fourpatients compare? A. Each patient's viral population would be unique, specifically adapted to deal with- and overcome- his or her unique immune system responses. B. The viral populations would still be genetically identical to each other and would be unchanged from the time of infection. C. The viral populations would have evolved to a new and more dangerous strain, but that strain would be identical across all four patients. This is the strain of virus found in every person suffering full blown AIDS

A. Each patients viral population would be unique, specifically adapted to deal with- and overcome- his or her unique immune system responses.

HIV has become an important source of mortality for humans. if AIDS presists as a major factor for humans for many generations in the future, natural selection theory predicts that __________. A. any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time B. AIDS should gradually become less variable with a lower mutation rate. C. Humans will develop weaker immune systems as an evolutionary response to natural selection. D. Individual humans evolve to become immune to AIDS as long as they are exposed to it as young children.

A. any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time.

How did the medium ground finch population on Daphne Major change following the 1977 drought? A.Average beak depth increased as a result of the selective pressure of the drought. B. Individual birds with small beaks experienced rapid beak growth in response to the altered availability of food. C. These finches switched from primarily eating seeds to primarily eating cactus fruits D. These medium ground finches evolved into large ground finches.

A. average beak depth increased as a result of the selective pressure of the drought

Scientists have found as many as 500 species of fish in the African Lake Victoria. What can account for this high level of diversity in a single habitat? A. Lake Victoria has a variety of environments such as rocky shores and muddy bottoms; this environment heterogeneity promotes speciation. B. Lake Victoria is a very ancient lake; therefore, there has been more time for a variety of species to evolve. C. A typical value of diversity for a lake the size of Lake Victoria is 500 fish species. D. Lake Victoria is located near the equator; therefore, it has great biodiversity, like the rainforests in South America.

A. lake victoria has a variety of environments such as rocky shores and muddy bottoms; this environment heterogeneity promotes speciation

A similar control experiment was performed with flies adapted to maltose, and similar results were obtained. What were these control experiments testing? A.These control experiments tested whether flies were more likely to choose mates from their own population than from another population adapted to the same medium. B.These control experiments tested whether the starch-adapted flies had a greater preference for like-adapted flies than did the maltose-adapted flies. C.These control experiments tested whether in the process of becoming adapted to different food sources, the flies had lost the ability to reproduce.

A. these control experiments teste whether flies were more likely to choose mates from their own population that from another population adapted to the same medium.

organisms that possess homologous structures probably ___________ A. use these homologous structures for the same purpose. B. Live in a similar environemnt C. Share a common ancestor that also had this structure D. By chance had similar mutations in the past

C. Share a common ancestor that also had this structure.

The following options are all reproductive barriers. Which one is an example of a prezygotic barrier in which the two different species do mate? A.Hybrid mules produced by mating donkeys and horses are sterile. B.Two dragonfly species regularly mate, but their gametes are incompatible. C.One bird species lives in wetlands, the other in dry forests; hence, they do not encounter each other. D.Two crayfish species cannot interbreed because their genitalia do not engage properly with each other.

B. 2 dragonfly species regularly mate, but their gametes are incompatible

In natural selection ________ determine which phenotypes are successful. A. future (anticipated) environmental conditions. B. Current conditions in the local environment C. Catastrophes that reduce the population to a very small number of suvivors D. chance of events

B. current conditions in the local environment

Which of the following examples uses the biological species concept to describe different species? A.Researchers use fossil evidence to define different dinosaur species. B.Female horses and male donkeys are able to mate, but their offspring (mules) are infertile. C.Two populations of birds mate and produce offspring that subsequently mate with one another and produce offspring. D. Researchers use DNA sequence data to conclude that two populations of bacteria are different species.

B. female horses and male donkeys are able to mate, but their offspring (mules) are infertile

Which population would be most likely to undergo relatively rapid allopatric speciation? A. A population of flowering plants lives along the shore of a pond about one kilometer from the nearest neighboring population. Hummingbirds regularly fly back and forth across this distance and transport pollen between the two populations. B. A group of wild horses is transported from Wyoming to a small desert island, previously without horses, off the coast of California. No additional horses reach the island thereafter. C. A group of birds develops a unique set of mating preferences so that they are unlikely to mate with other birds of the same species in the same geographic area. D. A population of snakes becomes separated from other populations on a very large island that is formed by rising sea levels. Occasionally, a snake or two swims from the mainland to the island or from the island to the mainland.

B. group of wild horses

For which of the following groups would the biological definition of species be useful? A.asexually reproducing plant and animal species that live in the present B.oaks and other sexually reproducing, extant (currently living) trees C.fossil bacteria, which are known to have reproduced asexually D.fossil dinosaurs, which are known to have reproduced sexually

B. oaks and other sexually reproducing, extant (currently living) trees

Sympatric speciation typically occurs through __________ and __________. A.polyploidy in plants; geographic barriers to dispersal in animals B.polyploidy in plants; habitat differentiation in animals C. genetic drift in plants; sexual selection in animals D.polyploidy in animals; habitat differentiation in plants

B. polyploidy in plants; habitat differentiation in animals

Which of the following statements about reinforcement is true? A.Reinforcement increases the number of intermediate phenotypes. B.Reinforcement is a type of natural selection. C.Reinforcement is also called dispersive selection. D.Reinforcement decreases the morphological difference between two new species.

B. reinforcement is a type of natural selection

Which of these is an example of temporal isolation? A.The average weight of the individuals in one species is 100 pounds; in the other species the average is 640 pounds. B.One species is diurnal (day active) and mates at high noon; the other is nocturnal (night active) and mates at midnight. C.One species can't dance; the other does not respond to species that can't dance. D. One species is found only in North America, the other only in Europe.

B.One species is diurnal (day active) and mates at high noon; the other is nocturnal (night active) and mates at midnight.

Change in population example:

Brown beetles survive to reproduce more than green beetles do. The brown allele increases in frequency.

Which of the following statements is supported by the data from the control group matings? A.Female starch flies from population #2 were more likely to mate with male flies from their own population than with flies from a different starch population. B.Male starch-adapted flies were less likely to mate with female starch-adapted flies than with female maltose-adapted flies. C. Flies were about as likely to mate with flies from different starch-adapted populations as with flies from their own starch-adapted population.

C. flies were about as likely to mate with flies from different starch-adapted populations as with flies from their own starch-adapted population

What is the major evidence for the punctuated equilibrium model of evolution? A.Transitional fossils are increasingly common as paleontologists continue to unearth new fossils. B. Populations do not adapt to the environment gradually. C. Many fossil species appear suddenly in the fossil record, persist unchanged for long periods, and then disappear without transitional forms. D. Big changes could never occur by a steady accumulation of smaller ones.

C. many fossil species appear suddenly in the fossil record, persist unchanged for long periods, and then disappear without transitional forms

In the mountains of the southeastern United States, there are many similar but distinct salamander species that are restricted to particular mountaintops or ridge systems. They are found in patches of suitable high-elevation habitat, separated by unsuitable lowland areas. This distribution pattern indicates __________. A.numerous sympatric speciation events B. a barrier based on temperature isolation C. numerous allopatric speciation events D. adaptive radiation

C. numerous allopatric speciation events

A subset of a population of birds leaves its habitat and colonizes a nearby island. After many generations, the island sinks and the population of birds living on the island returns to its original habitat. Which of the following statements most accurately describes the two bird populations? A.The populations will be able to interbreed even though they are different species. B.The populations were sympatric while they diverged. C.The birds were separated by dispersal. D.The populations will not be able to interbreed because they are different species.

C. the birds were separated by dispersal - meaning that one population migrated to an isolated location

Which of the following statements is best supported by the data on matings in the experimental groups? A.The starch-adapted flies and maltose-adapted flies appear to now be separate species as defined by the biological species concept. B.There is no evidence of reproductive isolation between the starch-adapted flies and maltose-adapted flies. C.The starch-adapted flies and maltose-adapted flies are not different species, but a reproductive barrier is forming between the populations.

C. the starch-adapted flies and maltose-adapted flies are not different species, but a reproductive barrier is forming between the populations

What was signifcant to Darwin about the fauna and flora of the Galapagos Islands? A. The organisms there were similar to fossils found elsewhere, indicating that the galapagos chain held many ancient species. B. The organisms there were teh same as those seen on similar island environments around the world C. The species on the Galapagos Islands were not similar to those anywhere else, indicating that they had been createdd specifically to inhavit this environment. D.The species were similar to South American species, indicating common descent, but they had been extensively modified and were well-adapted to island life.

D. The species were similar to south American Species, indicating common descent, but theyhad been extensively modified and were well-adapted to island life.

The different types of structures built by males of different populations of bowerbirds are likely the result of __________. A.artificial selection B.speciation C.cichlid diversification D.differences in female choice of preferred male courtship displays

D. differences in female choice of preferred male courtship displays.

Lake Victoria is home to a group of related fishes known as cichlids. Hundreds of forms are present, differing slightly in their color patterns, habitat use, and feeding behavior. What is the best method for scientists to determine conclusively whether the fish are members of a population that has a lot of variation or whether they are members of entirely different species? A.Conduct studies on comparative anatomy to find morphological differences between the species. B.Scientists compare DNA sequences because the DNA of members of the same species should be identical. C.Keep them together in aquariums to see if they will interbreed and produce fertile offspring. D.Observe them together under natural conditions to see if they interbreed to produce fertile offspring.

D. observe them together under natural conditions to see if they interbreed to produce fertile offspring

A diploid cell in a plant undergoes chromosome duplication but fails to divide properly, initiating a tetraploid (4n) branch. This branch produces a 4n flower. What can happen next? A. The 4n flower produces 4n (tetraploid) gametes, which then self-fertilize to produce fertile offspring. B. The 4n flower produces 1n (haploid) gametes, which then cross-fertilize with gametes from the original diploid parent species to produce fertile offspring. C.The 4n flower produces 2n gametes, which then cross-fertilize with gametes from the original diploid parent species to produce fertile offspring.T D. The tetraploid (4n) flower produces 2n gametes and may then be able to self-pollinate to produce fertile 4n offspring.

D. the tetraploid (4n) flower produces 2n gametes and may then be able to self-pollinate to produce fertile 4n offspring -This is the fastest route to a new species through polyploid sympatric speciation. The tetraploid offspring are fertile because they have pairs of homologous chromosomes that can match up properly and separate in meiosis to complete the life cycle.

When populations of closely related pied flycatchers and collared flycatchers live in different geographic areas, the males of both species look a lot alike. However, when populations of the two species share a common geographic area, there are significant differences in the appearance of the two species. What conclusions might you draw from this situation? A.Even though the colors of the males of the two species are very similar in the geographically isolated populations, you would expect that when researchers performed mate-choice experiments, females would never chose males from the wrong species. B. This is a case of random variation within the population. C. Hybrid offspring of the two species are more fit than either of the parent species. Eventually the two hybridizing species will fuse into one. D. This is a case where hybrid offspring of the two species are less fit than either of the parent species. In the geographic areas where the populations overlap, natural selection has reinforced color differences that serve as reproductive barriers between the two species.

D. this is a case where hybrid offspring of the two species are less fit than either of the parent species. In the geographic areas where the populations overlap, natural selection has reinforced color differences that serve as reproductive barriers between the two species.

which best describes the fossil record? A. the fossil record is a sequence of fossils arranged from oldest (top layers of rock) to youngest (bottom layers of rock). B. The fossil record is the sequence in which fossils are found in layers of sedimentary rock. It is chaotic (jumbled), making it difficult to find any consistent patterns in life's evolution. C. The fossil record is a database in which fossil names and dates are collected. D. The fossils record is the highly ordered sequence in which fossils are found in layers of sedimentary rock.

D.the fossil record is the highly ordered sequence in which fossils are found in layers of sedimentary rock.

A biologist spends her summer break collecting frogs from a remote jungle in Peru. She discovers two distinct color forms that could be variants of a single species or two different species. What would be the most direct test of their species statusunder the biological species concept?

Observe mating in the natural environment of the two groups. If the two forms do not mate with each other, they are different species.

All of life is related through common ancestry, accounting for the _______ of life.

Unity

Mutant tetraploid plants _____.

are unable to interbreed with a diploid plant-This is why polyploidy is a mechanisms of plant speciation.