Unit3_Evolution_TestReview2

What makes up a population's gene pool?

• All the alleles carried by members of the population

• All the favorable alleles carried by members of the population

• All the alleles expressed in members of the population

• All the dominant alleles carried by members of the population

Which of these is required for natural selection?

• All individuals of a population must be identical

• There must be a small number of individuals in a population

• There must be variation among members of a population

• A population of individuals must be forced out of their natural habitat

A certain mammal population contains two alleles for claw length. Some members of the population have long claws that enable them to climb trees, while most members do not. When a new predator that feeds on these mammals is introduced into this environment, some long-clawed mammals climb up trees to escape.

Which statement describes the MOST LIKELY impact of natural selection on the population over the coming generations?

• The alleles for long claws will increase in the population

• The alleles for long claws will decrease in the population

• The alleles for short claws will disappear from the population

• The alleles for short claws will increase in the population

Why do some strains of bacteria become resistant to antibiotics?

• The bacteria grow in habitats protected from antibiotics

• The bacteria develop a method of surviving without energy

• Some bacteria that live in host organisms are not affected by antibiotics

• Some bacteria develop an adaptation that enables them to survive in the presence of antibiotics

What is a factor required for a population to be in Hardy-Weinberg equilibrium

• nonrandom mating

• absence of genetics drift

• small population size

• presence of inheritable mutations

Two closely related forms of the fruit fly Drosophila mate at different times of the day. One type mates only in the morning, while the other mates only in the afternoon. Which statement MOST LIKELY describes the two forms of Drosophila?

• They share the same gene pool

• They belong to the same species

• They make up two separate species

• They are part of populations in genetic equilibrium

A population of 50 land animals has a small number of alleles for one trait. After being attacked by a pack of predators, only one-half of the population remains. Which term BEST describes the change in allele frequencies for this trait in the population?

• Gene flow

• Mutation

• Nonrandom mating

• Genetic drift

A single population of lizards living on an island in the Pacific Ocean becomes separated into two populations due to volcanic activity. Which statement describes the MOST likely outcome of this event after several generations?

• Different traits will appear in each population

• One population will become extinct

• The two populations will maintain the same genotypes

• Each population will begin to breed at a different time

Which term describes parts of an organism that have similar structure but a different function?

• Analogous structures

• Embryological structures

• Fossilized structures

• Homologous structures

Fossils of an animal called Ichthyostega show that it had lungs and legs. It also had gills, teeth, and a tail similar to that of a fish. Ichthyostega is considered to be one of the first amphibians. Other fossils show that amphibians lost these fishlike features.

How might scientists interpret the fossil Ichthyostega?

• It was an early type of primitive fish

• It might be an animal that could live on land and water

• It was the last example of an amphibian with lungs

• It might be a connection to birds that were also efficient swimmers