AP Biology Assessment: Evolution of Populations

There are three main mechanisms that can cause allele frequency change: 1) Natural Selection 2) ____________________ (chance events that alter allele frequencies)

• Genetic Drift

• Gene Flow

• Mutation

• Artificial Selection

In The Origin of Species, Darwin provided abundant evidence that life on Earth has evolved over time, and he proposed (a)   as the primary mechanism for that change.

Darwin proposed that natural selection could not cause evolutionary change unless individuals differed in their ____________________ characteristics.

• inherited

• physical

• behavioral

• environmental

Mendel presented his findings on plant hybridization experiments in a paper titled “Experiments on Plant Hybrids”. What was the main focus of Mendel's experiments?

• Animal hybridization

• Plant hybridization

• Soil composition

• Weather patterns

Phenotype is the product of an inherited (a)   and many environmental influences. In a human example, bodybuilders alter their phenotypes dramatically but do not pass their huge muscles on to the next generation.

__________ characters, such as the purple or white flower colors of Mendel’s pea plants can be classified on an either-or basis (each plant has flowers that are either purple or white).

• discrete

• continuous

• variable

• random

A heterozygous individual has two different alleles for a given locus, whereas a homozygous individual has two ________________ alleles for that locus.

• identical

• different

• mutated

• recessive

Gene variability (that is, average heterozygosity) tends to be greater than nucleotide variability for the following reason: A gene can consist of thousands of (a)   (the basic building blocks of nucleic acids). A difference at only one of these nucleotides can be sufficient to make two alleles of that gene different and thereby increase gene variability.

In addition to variation observed within a population, species also exhibit ____________________ variation, differences in the genetic composition of separate populations.

• geographic

• temporal

• behavioral

• physiological

The ultimate source of new alleles is (a)   , a change in the nucleotide sequence of an organism’s DNA.