BIO-1407 Practice Final Exam

Which of the following mechanisms directly increases genetic variation in a population?

• Stabilizing selection
• Directional selection
• Mutation
• Genetic drift

Answer explanation

Mutations introduce new alleles into a population, increasing genetic variation. Selection and drift alter existing variation, but only mutation generates new alleles.

Tags

NGSS.HS-LS3-2

A population of insects develops resistance to a pesticide over several generations. Which evolutionary mechanism is primarily responsible for this adaptation?

• Gene flow
• Natural selection
• Mutation
• Genetic drift

Answer explanation

Natural selection favors individuals with traits that confer resistance, leading to an increased frequency of those alleles.

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

Microevolution involves:

• Changes in allele frequencies within a population
• The origin of new animal phyla
• Large-scale changes above the species level
• Extinction events

Answer explanation

Microevolution refers to changes in allele frequencies within a population.

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

Two closely related frog species breed in the same pond but mate at different times of year. What type of reproductive barrier is this?

• Temporal isolation
• Mechanical isolation
• Behavioral isolation
• Gametic isolation

Answer explanation

Temporal isolation occurs when species breed at different times.

Which of the following best illustrates the biological species concept?

• Birds with similar coloration are considered the same species
• Wolves and dogs can mate and produce fertile offspring
• Organisms that live in the same environment
• Two populations are separated by a river

Answer explanation

The biological species concept is based on the ability to interbreed and produce fertile offspring.

Which method is commonly used to determine the absolute age of fossils?

• Phylogenetic analysis
• Comparative anatomy
• Radiometric dating
• Carbon copying

Answer explanation

Radiometric dating measures the decay of radioactive isotopes.

Which of the following provides the strongest evidence for the endosymbiotic origin of mitochondria?

• Cell wall structure
• Nucleus containing chromosomes
• Double membranes and their own DNA
• Presence of chlorophyll

Answer explanation

Mitochondria have double membranes and their own circular DNA.

Which of the following events led to the extinction of many species at the end of the Cretaceous period?

• Ice age
• Asteroid impact
• Formation of the ozone layer
• Continental drift

Answer explanation

An asteroid impact is widely accepted as the cause of the mass extinction at the end of the Cretaceous period.

Tags

NGSS.HS-ESS2-2

NGSS.HS-LS4-5

Which of the following is NOT one of the three domains of life?

• Plantae
• Archaea
• Bacteria
• Eukarya

Answer explanation

The three domains are Bacteria, Archaea, and Eukarya.

A group that consists of an ancestral species and all its descendants is called a:

• Paraphyletic group
• Family
• Clade
• Polyphyletic group

Answer explanation

A clade, or monophyletic group, includes an ancestor and all of its descendants.