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 ____________________ 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 ____________________ 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 ____________________ (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 change in the nucleotide sequence of an organism’s DNA.