Free SAT Biology Genetics & Evolution Questions and Answers

Question 1

What is the primary mechanism of evolution?

Accepted Answer

Natural selection

Answer

Natural selection is the primary mechanism driving evolution, as proposed by Charles Darwin. It describes the process where organisms better adapted to their environment tend to survive and produce more offspring. Over time, this leads to changes in the genetic makeup of populations, favoring advantageous traits and leading to the development of new species.

Question 2

Which structure carries genetic information?

Accepted Answer

DNA

Answer

Deoxyribonucleic acid (DNA) is the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses. It contains the hereditary material that is passed from parents to offspring. DNA's double helix structure allows it to store vast amounts of information in a stable form.

Question 3

What term describes a change in DNA sequence?

Accepted Answer

Mutation

Answer

A mutation is a permanent alteration in the DNA sequence that makes up a gene or chromosome. These changes can range from a single nucleotide substitution to large-scale chromosomal rearrangements. Mutations are the ultimate source of genetic variation, which is essential for evolution, though they can also be harmful.

Question 4

What is genetic drift?

Accepted Answer

Genetic drift

Answer

Genetic drift is a random change in the frequency of alleles (gene variants) in a population over generations. Unlike natural selection, which is driven by adaptation, genetic drift is purely by chance, especially significant in small populations. It can lead to the loss of some alleles and the fixation of others, regardless of their adaptive value.

Question 5

What is a phenotype?

Accepted Answer

Observable traits

Answer

A phenotype refers to the observable physical or biochemical characteristics of an organism, resulting from the interaction of its genotype with the environment. Examples include hair color, height, or the presence of a disease. While primarily determined by genes, environmental factors can also influence the final expression of the phenotype.

SAT - Biology Subject Test Practice Test

SAT - Biology Subject Test Practice Test

Free SAT Biology Genetics & Evolution Questions and Answers