Unit 7 Test Review

Darwin drew ideas for his theory from observations of organisms on _________.

• the Samoan Islands
• Manhattan Island
• the Hawaiian Islands
• the Galápagos Islands

Which of the following lists the four main principles of natural selection?

• adaptation, inheritance of acquired characteristics, overproduction of offspring, variation
• adaptation, inheritance of acquired characteristics, heritability, variation
• adaptation, descent with modification, overproduction of offspring, variation
• adaptation, descent with modification, heritability, variation

Consider the model for natural selection. In a population of living things, genetic variation exists. One source of variation is mutation. Which scenario listed here could be a mutation that causes members of a population to die out?

• In a population of fast-running cheetahs, some are born that run slower than most.
• In a populations of birds, mutations result in different beak sizes so the birds do not compete for food in the area.
• In a population of sunflowers, mutations cause some flower heads to produce more seeds.
• In a population of brownish rabbits that live in the tundra, some are born with fur that turns white in the winter.

A trait that allows organisms/populations to be better suited to its environment is called a(n) _________.

• accommodations
• variation
• adaptation
• acclimation

Natural selection could not occur without __________.

• genetic variation in species
• stable environments
• competition for unlimited resources
• gradual warming of the Earth

A bird that can easily out-compete other birds for food & can produce many eggs has a high ____.

• fitness
• mutation rate
• life expectancy
• adaptability

The peppered moth exists in 2 distinct colorations/phenotypes, black and peppered. Prior to the Industrial Revolution, peppered moths outnumber black moths 98% to 2%. The Industrial Revolution spewed coal ash into the air causing a discoloration on the trees on which they lived. The black moth now outnumbered the peppered moths 95% to 5%. In this example, scientists discovered that ________.

• the color of the moths was not important
• birds preferred the flavor of light-colored moths
• coloration was not an inherited trait
• moths whose color matched that of the tree trunks were more likely to survive

Variations in genotype can be caused by all of the following except _________.

• mutations
• recombination of genes during crossing over
• asexual reproduction
• hybridization

When individuals from two populations of squirrels can no longer successfully mate with each other, the chance that speciation will occur _________.

• decreases
• becomes zero
• stays the same
• increases

In any field of sunflowers, the height of the plants vary. Birds first eat the seeds from the tallest plants. If this eating pattern continues season after season, what would happen to sunflowers over time?

• They would get shorter.
• They would become extinct.
• They would begin to reproduce asexually.
• They would stop producing seeds.