Biology Chapter 14

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

a) 1

A new species can arise in a single generation _____. a) through geographic isolation b) in rapidly evolving species such as insects c) if a change in chromosome number creates a reproductive barrier d) if two forms of a species begin to use different habitats or food resources

c) if a change in chromosome number creates a reproductive barrier

The first tetrapods (four-legged animals) were amphibians, which evolved from a specialized group of lobed-fin fish. An unusual fossilized animal (named Tiktaalik) was recently found; this animal possessed a mixture of fish and amphibian characteristics. What is the term used to describe such an intermediate organism? a) homologous b) mutant c) transitional form d) vestigial

c) transitional form

Microevolution is _____. a) dramatic changes that take place over long periods of time speciation b) evolution on a molecular level c) changes in the gene pool of a population from one generation to the next

changes in the gene pool of a population from one generation to the next

_____ is the process by which haploid gametes form a diploid zygote. a) Embryogenesis b) Meiosis c) Gastrulation d) Fertilization e) Mitosis

d) Fertilization

Color is an inherited trait in beetles. If brown beetles move into a population from a nearby island, which of the following statements is correct? a) Natural selection causes the frequency of the green allele to increase. b) Gene flow causes the frequency of the green allele to increase. c) This is an example of genetic drift. d) Natural selection causes the frequency of the brown allele to increase. e) Gene flow causes the frequency of the brown allele to increase.

Gene flow causes the frequency of the brown allele to increase.

In a population with brown and green alleles for color, genetic drift a) causes populations to become better adapted to their environments. b) has more effect on the evolution of a small population. c) has more effect on the evolution of a large population. d) occurs when individuals move into or out of a population, changing the allele frequencies in the population. e) always increases the frequency of brown alleles in the population.

has more effect on the evolution of a small population.

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

hybridization

Two species of clams inhabit the same marine habitat along the Atlantic coast. One releases gametes into the water in early spring, and the second species releases gametes into the water in late summer. Which type of reproductive barrier is at work between these species? a) habitat isolation b) gametic isolation c) reduced hybrid viability d) temporal isolation

temporal isolation

If color is an inherited trait in beetles, and birds are more likely to eat brown beetles than green beetles, a) this causes the population to evolve due to gene flow. b) the frequency of the green allele will increase. c) the frequencies of the brown and green alleles will not change. d) this causes the population to evolve due to genetic drift. the frequency of the brown allele will increase.

the frequency of the green allele will increase.

The number of species on an island remains relatively constant when _____. a) species richness increases b) the rate of successful colonization equals the extinction rate c) the rate of successful colonization is less than the extinction rate d) the rate of successful colonization is greater than the extinction rate e) none of these occur

the rate of successful colonization equals the extinction rate

New branches form on the tree of life through the process of __________. microevolution genetic drift natural selection speciation

speciation

Which of the following list of assumptions was part of Charles Darwin's theory of natural selection? 1. Earth and its life are very old. 2. Populations produce more offspring than their environment can support. 3. Organisms vary in heritable ways. 4. Mutation rates were higher in the past than they are now. 1. Organisms vary in heritable ways. 2. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 3. Some traits improve the survival and reproduction of individuals who possess them. 4. Mutations directly cause the changes in species. 1. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 2. Some traits improve the survival and reproduction of individuals who possess them. 3. There is little genetic variability. 4. Organisms vary in heritable ways. 1. Organisms vary in heritable ways. 2. Some traits improve the survival and reproduction of individuals who possess them. 3. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 4. Earth and its life are very old.

1. Organisms vary in heritable ways. 2. Some traits improve the survival and reproduction of individuals who possess them. 3. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 4. Earth and its life are very old.

Humans are diploid and have 46 chromosomes. How many chromosomes are found in each human gamete? 12 23 36 45 92

23

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. 1 2 3 4 5

4

According to a recent survey of many studies, an average plant or animal lineage might produce a new species approximately once every _____. 50 years 500 years 5 million years 5,000 years

5 million years

Which of the following statements best describes how the process of natural selection works? a) Better-adapted individuals will leave behind more offspring to carry on their genes, producing a dynamic "fit" between a population and its changing environment. b) Natural selection will lead to increasing population size over time. c) Only the strongest survive. d) Beneficial mutations will arise in response to a new environment.

Better-adapted individuals will leave behind more offspring to carry on their genes, producing a dynamic "fit" between a population and its changing environment.

Why is a new island more hospitable to colonizers than an older island is? a) The intensity of both competition and predation is less on the newer island. b) Competition is more intense on the newer island. c) Predation is less of a factor on older islands. d) The extinction rate is higher on the newer island. e) Competition is less intense on the newer island.

The intensity of both competition and predation is less on the newer island.

Remember that color is an inherited trait in beetles. Which of the following is an example of natural selection? a) Green beetles leave more offspring than brown beetles because they are better at finding food. b) Green beetles and brown beetles always leave the same number of offspring. c) Green beetles migrate out of the population, and brown beetles migrate into the population. d) A storm kills more green beetles than brown beetles by chance. e) Green beetles migrate out of the population.

a) Green beetles leave more offspring than brown beetles because they are better at finding food.

According to island biogeography, what is the relationship between an island's distance from the mainland and the number of species present on the island? a) The farther an island is from the mainland, the fewer the number of species found on the island. b) There is no relationship between the distance from the mainland and the number of species found on an island. c) The farther an island is from the mainland, the larger the number of species found on the island. d) The closer an island is to the mainland, the fewer the number of species found on the island. e) The closer an island is to the mainland, the fewer the number of species found on the island; and the farther an island is from the mainland, the larger the number of species found on the island.

a) The farther an island is from the mainland, the fewer the number of species found on the island.

Scientists estimate that _____% of plant species are polyploids, mostly generated through _____. a) over 75 ... hybridization between two species b) less than 10 ... hybridization between two species c) 50 ... tetraploids arising from a single diploid parent species d) 25 ... hybridization between two species

a) over 75 ... hybridization between two species

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 is located near the equator; therefore, it has great biodiversity, like the rainforests in South America. b) A typical value of diversity for a lake the size of Lake Victoria is 500 fish species. c) Lake Victoria has a variety of environments such as rocky shores and muddy bottoms; this environment heterogeneity promotes speciation. d) Lake Victoria is a very ancient lake; therefore, there has been more time for a variety of species to evolve.

c) Lake Victoria has a variety of environments such as rocky shores and muddy bottoms; this environment heterogeneity promotes speciation.

Which population would be most likely to undergo relatively rapid allopatric speciation? a) 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. 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 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. 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) 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.

In which of the following situations is adaptive radiation least likely to occur? a) A species has flexible morphological structures that lend themselves to specialization. b) A species with inflexible morphological traits finds itself in a species-rich, highly competitive environment. c) The dominant organisms in an area become extinct. d) A new island chain forms far from shore and is reached by a few groups of long-distance colonists.

b) A species with inflexible morphological traits finds itself in a species-rich, highly competitive environment.

Why was Darwin's acceptance of an ancient, continuously changing Earth so important in his development of his ideas about evolution? a) Darwin hypothesized that as Earth changed due to volcanic eruptions, new species would appear from deep within the Earth. b) Darwin hypothesized that species changed gradually, over long spans of time, in response to diverse and changing habitats. c) He had to accept that Earth could change in order to also accept that organisms can change. d) Darwin hypothesized that as Earth changed, a divine force replaced the existing species with new species that were perfectly suited to the new environment.

b) Darwin hypothesized that species changed gradually, over long spans of time, in response to diverse and changing habitats.

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) Two dragonfly species regularly mate, but their gametes are incompatible.

The main focus of Charles Darwin's studies was on the gradual process of adaptation within populations. In other words, microevolution occurs by means of natural selection. Although critical to evolution this form of change, __________. a) occurs mainly in small, isolated populations b) cannot account by itself for the increase in species diversity over time c) is the main means by which new species arise d) explains all important forms of evolutionary change

b) cannot account by itself for the increase in species diversity over time

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

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

What is shown in the figure below a) directional selection b) punctuated equilibrium c) gradualism d) stabilizing selection

b) punctuated equilibrium

Speciation is likely to occur between a parent population and a population that has become allopatric if _____. a) there is a lot of gene flow between the two populations b) the allopatric population is small and is isolated from the parent population by a formidable barrier to dispersal c) both populations are large and exhibit a sufficient diversity of alleles d) it is in a similar environment to the "parent" population

b) the allopatric population is small and is isolated from the parent population by a formidable barrier to dispersal

When a horse and a donkey mate, they produce infertile hybrids called mules. According to the _____ species concept, horses and donkeys are ____ biological ... the same species biological ... different species ecological ... the same species ecological ... different species

biological ... different species

Which of the following statements about reproductive barriers and speciation is true? a) Reproductive barriers can arise only when populations are geographically separated. b) Reproductive barriers can arise in the absence of geographic isolation, but the process of speciation would be slow and take many generations. c) Populations can split into separate species even in the absence of reproductive barriers. d) Speciation can occur with even a single gene mutation if that mutation involves reproductive barriers.

d) Speciation can occur with even a single gene mutation if that mutation involves reproductive barriers.

Why is the morphological species concept still used to define and describe species? a) If two organisms look alike, they must be the same biological species. b) The morphological species concept defines a species in terms of its reproductive behavior, which is the most direct way to identify biological species. c) Physical traits clearly define unique branches on the tree of life. d) This is the most convenient way of identifying species, and it is one of the few ways to identify fossil or asexual species.

d) This is the most convenient way of identifying species, and it is one of the few ways to identify fossil or asexual species.

Mutant tetraploid plants _____. a) are usually sickly b) are able to interbreed with their parents c) have an odd number of chromosomes d) are unable to interbreed with a diploid plant e) unable to self-fertilize

d) are unable to interbreed with a diploid plant

The evolution of populations due to chance is a) has more effect in large populations than in small populations. b) genetic variation. c) natural selection. d) genetic drift. e) gene flow.

d) genetic drift

Genetic drift is _____. a) an important microevolutionary mechanism in large populations b) adaptive c) the mechanism by which new alleles originate d) more likely to have an impact on small populations

d) more likely to have an impact on small populations

What is the relationship between colonizing success and the number of species already established on an island? a) As the number of established species on an island increases, colonizing success also increases. b) As the number of established species on an island decreases, colonizing success also decreases; and as the number of established species on an island increases, colonizing success also increases. c) There is no relationship between the number of established species on an island and colonizing success. d) As the number of established species on an island decreases, colonizing success also decreases. e) As the number of established species on an island increases, colonizing success also decreases.

e) As the number of established species on an island increases, colonizing success also decreases.

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

polyploid