evolution

The diagram illustrates an embryonic stage of two organisms.Which of the following can be determined by observing the embryos shown in the diagram? 

• The organisms share a common ancestry.
• The organisms belong to the same genus.
• The organisms are native to the same geographic areas.
• The organisms will grow into anatomically similar adults.

Scientists are studying the evolutionary history of a group of plants in the United States, and they developed an evolutionary tree, as shown below.Which statement can be inferred from the evolutionary tree?

• Species 1 is most closely related to Species 8.
• Species 2 is most closely related to Species 3.
• Species 3 is most closely related to Species 7.
• Species 5 is most closely related to Species 6.

Natural selection is best described as

• a change in an organism in response to a need of that organism
• a process of nearly constant improvement that leads to an organism that is nearly perfect
• differences in survival rates as a result of different inherited characteristics
• inheritance of characteristics acquired during the life of an organism

Which occurrence represents an example of evolution?

•  Exposure to radiation reduces the rate of mutation in leaf cells.
• A mutation in a liver cell causes a person to produce an enzyme that is less efficient.
•  Cells in a zygote eventually change into bone cells or skin cells
• Some antibiotics are almost useless, because pathogens have developed a resistance to these antibiotics.

Natural selection results in change in a population's _____________ traits over time.

• inherited

• acquired

Individuals undergo evolution.

• True

• False

What is speciation?

• combining of two species to form one with different traits

• Intentional breeding designed to maintain a desired trait

• timing of mating that prevents normal sexual selection

• A population splits and accumulates different genes in the new groups

Genetic drift is change in the allele frequency of a population due to...

• random chance
• natural selection
• non-random mating (sexual selection)
• artificial selection

Evolution, gravity, and plate tectonics are all examples of scientific...

• hypotheses

• theories

• laws

How does a species change over time?

• by adapting to the environment

• changes in the gene frequencies in a population

• acquiring new traits

• they do not change