Chapter 4

Question 1

Microevolution

Answer 1

Occurs on gene frequencies, relatively few genes changing from generation to generation. Slow accumulation over time.

Question 2

Macroevolution

Answer 2

Significant physical changes based on many genetic changes.

Question 3

Deme

Answer 3

Local population that interbreeds

Question 4

Gene Pool

Answer 4

All the genetic information in a breeding pop.

Question 5

Reproductive isolation:

Answer 5

mechanism that prevents two populations from interbreeding (diff. continents)

Question 6

Species

Answer 6

groups of reproductively isolated organisms

Question 7

Homologous chromosomes

Answer 7

A pair of chromosomes that carry genes for the same set of traits

Question 8

Gene

Answer 8

A segment of DNA that codes for some trait

Question 9

Allele

Answer 9

A variant of a gene that expresses a trait in different form

Question 10

Homozygous

Answer 10

An individual who inherits two of the same allele for a particular trait.

Question 11

Heterozygous

Answer 11

An individual who inherits two different alleles for a particular trait

Question 12

Dominant Alleles

Answer 12

Always expressed in the phenotype if present. AA, Aa.

Question 13

Recessive Alleles

Answer 13

Only expressed if the genotype is aa (recessive genes).

Question 14

Skin colour

Answer 14

Determined by melanocytes = produce melanin, determines how dark or light someone will be.

Question 15

Random Assortment

Answer 15

The chance distribution of chromosomes to daughter cells during meiosis; along with recombination, a source of genetic variation (but not new alleles) from meiosis

Question 16

Hardy-Weinberg Equilibrium

Answer 16

Predicting genotype frequencies in the next generation, ie. if evolution will take place.

Question 17

Mutation

Answer 17

Molecular alteration in genetic material. Only source of new alleles. Chromosomal duplications: Klinefelter’s syndrome, trisomy.

Question 18

Fitness

Answer 18

Most optimal for that situation, not necessarily large + strong. Could be small.

Question 19

Exogamous vs. Endogamous marriage

Answer 19

Marrying outside (more gene flow) vs. inside (less gene flow) a cultural/genetic group.

Question 20

Founder Effect

Answer 20

Type of genetic drift. Occurs when a small band of “founders”leaves its parent group and forms a colony elsewhere.

Question 21

Recombination

Answer 21

Affects how some genes act, and slight changes of gene function can become material for natural selection to act upon.

Question 22

Sickle-Cell Anemia

Answer 22

severe inherited hemoglobin disorder in which red blood cells collapse when deprived of oxygen. Results from 2 copies of a mutant allele.

Question 23

Mendelian Inheritance

Answer 23

Lots of these traits are considered to be these, ABO blood syst. one of them.

Question 24

What is sickle-cell anemia?

Answer 24

Balanced polymorphism.

Question 25

Huntington Disease

Answer 25

Caused by a dominant mutation on chromosome 4.

Question 26

What makes natural selection?

Answer 26

Survival of the fittest and reproduction of the fittest.

Question 27

What Causes Evolution?

Answer 27

Mutation, Natural Selection, Genetic Drift, and Gene Flow