Chapter 23 & 13

Question 1

Genetic Variation

Answer 1

Variation in heritable traits, a prerequisite to natural selection

Question 2

Gene

Answer 2

Unit of heredity

Question 3

Allele

Answer 3

A form of genes

Question 4

Homozygote

Answer 4

Possessing two of the same alleleH

Question 5

Heterozygote

Answer 5

Possessing different alleles (Dd, Bb)

Question 6

How does mutation influence genetic variation

Answer 6

Mutation is a difference in DNA, which when replicated causes a change in the alleles

Question 7

Asexual reproduction

Answer 7

Reproduction without fusion of gametes, based on mitosis

Question 8

Homologous Chromosomes

Answer 8

A pair of chromosomes with the same genes, one copy from each parent.

Question 9

Independent Assortment

Answer 9

Random distribution of homologous chromosomes during meiosis

Question 10

Mitosis

Answer 10

The division of cells in a way where two genetically identical diploid cells are made

Question 11

Meiosis

Answer 11

Two divisions of a cell where four genetically unique haploid cells are made.

Question 12

What phases of Meiosis does Independent Assortment happen in

Answer 12

Metaphase I & II

Question 13

Crossing Over

Answer 13

Homologous chromosomes exchanging reciprocal portions of themselves

Question 14

Random Fertilization

Answer 14

The random mating of subjects in a population.

Question 15

Species vs Population

Answer 15

Populations are a localized group of interbreeding individuals, species are groups capable of sharing alleles with oneanother

Question 16

Directional Natural Selection

Answer 16

Average phenotype of a population changes in one direction

Question 17

Disruptive

Answer 17

Eliminates phenotypes near the average value

Question 18

Stabilizing NS

Answer 18

Reduces both extremes in the population, and no change in the average value (genetic variation is reduced)

Question 19

Genetic Drift

Answer 19

Random changes in allele frequency; may cause fitness to decrease

Question 20

Founder Effect

Answer 20

Change in allele frequencies occuring when a new population is established

Question 21

Bottleneck Effect

Answer 21

A reaction to the number of alleles present in a population; certain alleles overrepresented among survivors.

Question 22

Gene flow

Answer 22

Movement of alleles into or out of a population due to the movement of fertile individuals.

Question 23

Frequency-Dependent selection

Answer 23

Oscillation of two averaged phenotypes

Question 24

Heterozygote Advantage

Answer 24

when individuals with two different alleles (heterozygotes) for a particular gene have a higher fitness than those with two identical alleles