Unit 4 Exam

How does the biological species concept define a species?

A species is a population whose members can breed and produce fertile offspring.

Use the geologic time scale (Figure 15-18) to estimate how long prokaryotes inhabited Earth before eukaryotes evolved.

About 1.3 Billion Years.

9. How is evidence from DNA useful in understanding the evolution of species?

Comparing the DNA among species indicates if they share a recent common ancestor. The greater the DNA difference, the less closely related the species.

Describe conditions that make it possible for a species to undergo adaptive radiation.

Conditions favoring adaptive radiation may include geographic isolation, diverse habitats, and environments not densely inhabited.

10. How are pesticide-resistant insects an example of natural selection?

Pesticides in the environment select in favor of those in a population that have resistance to that pesticide.

How does descent with modification explain the diversity of life?

Species accumulate adaptations to diverse environments. They become modified from previous ancestors in various ways.

Which of the following provides clues about the size and structure of once-living organisms? a. fossils b. DNA and proteins from the organisms c. vestigial structures d. development of embryos

a) fossils

Mass extinctions that occurred in the past a. were followed by diversification of some of the survivors. b. occurred roughly every million years. c. cut the number of species to the few left today. d. wiped out land animals but had little effect on marine life.

a) were followed by diversification of some of the survivors.

What process most likely could account for the diversity of finch species on the Galápagos Islands? a. convergent evolution b. adaptive radiation c. punctuated equilibrium d. continental drift

b

What statement is not an observation or inference on which Darwin's theory of natural selection is based? a. Variations among individuals exist in a population. b. Poorly adapted individuals never produce offspring. c. Individuals whose inherited characteristics give them advantages in their environment will generally produce more offspring. d. Species living today descended with modification from earlier species.

b) Poorly adapted individuals never produce offspring.

Which of the following is not an example of a reproductive barrier? a. Mallard ducks and pintail ducks mate at different times of the year. b. Two species of flowers are pollinated by different insects. c. Two populations of oak trees grow on opposite banks of a river. d. Two species of leopard frogs have different mating calls.

c) Two populations of oak trees grow on opposite banks of a river.

Divisions on the geologic time scale are marked by a. gradual disappearance of species. b. regular intervals of time. c. distinct changes in the types of fossilized life. d. radioactive dating.

c) distinct changes in the types of fossilized life.

What genotype is the most beneficial for individuals living in regions where malaria is common? a. homozygous dominant (no sickle cell alleles) b. homozygous recessive (two sickle cell alleles) c. heterozygous (one sickle cell allele) d. no difference among the genotypes

c) heterozygous (one sickle cell allele)

Organisms in the same clade must a. belong to the same genus. b. belong to the same species. c. share a common ancestor that belongs to the same clade. d. not share a common ancestor.

c) share a common ancestor that belongs to the same clade.

Which of the following is an incorrect match? a. Lyell—suggested physical changes to Earth result from geologic processes occurring over long periods of time. b. Lamarck—proposed that organisms adapt to their environment. c. Darwin—developed the theory of natural selection as a mechanism of change in species. d. Malthus—thought that characteristics acquired during an organism's lifetime can be passed on to the next generation.

d) Malthus—thought that characteristics acquired during an organism's lifetime can be passed on to the next generation.

Artificial selection is similar to natural selection in that both processes a. were suggested by Darwin. b. adapt species to their environments. c. occur over many millions of years. d. depend on variation among individuals.

d) depend on variation among individuals.

Two worms in the same class must also be grouped in the same a. order. b. genus. c. family. d. phylum.

d) phylum

What is microevolution?

A change in frequency of alleles in a population from generation to generation.

8. Give an example in which differences in behavior prevent similar species from interbreeding.

Example Answer - Two species of birds with different mating songs will not attract mates from one another.

How does punctuated equilibrium account for the relatively rare number of fossils that link newer species to older ones?

Fossils from newly evolving species are rare because the populations are small and changes are concentrated in a short time span relative to the geologic time scale.

8. Explain how the formation of fossils provides a chronological record of past life forms.

Fossils often form when organisms become trapped in sedimentary rock. New Layers form over Old Layers.

6. How did Darwin's experiences during his voyage later affect his views about species?

He realized species changed, and searched for a mechanism to explain how...

How much of the classification in Figure 15-24 do humans share with the leopard?

Humans are in same kingdom, phylum Chordates, and class mammals as leopards.

In what ways can evolution be termed a "remodeling process"? Give an example

In general, new structures do not suddenly appear; existing structures become modified, or become adapted to new functions.

How does continental drift contribute to macroevolution?

It can produce changes in climate and habitat, possibly causing extinctions or conditions that favor surviving species to undergo adaptive radiation.

13. How does natural selection lead to adaptation?

It favors survival of individuals with helpful variations. These individuals intern reproduce in greater numbers changing the population.

12. How is developmental biology helpful to biologists who study?

It reveals how genetic can effect the form of organisms.

11. Describe what can happen to a gene pool as a result of the bottleneck effect.

The bottleneck effect greatly reduces the number of individuals in a population, by chance can also change the frequency of certain alleles.

What are derived characters, and how are they used in taxonomy?

They are Homologous characteristics that unite a group of organisms into one clade.