Genetics and Evolution

Question 1

Alleles

Answer 1

Alternative forms of a gene. Dominant allele only
requires 1 copy in order to be expressed. Recessive
allele requires two copies in order to be expressed.

P + q = 1

P^2 +2Pq + q^2 = 1

Question 2

Genotype:

Answer 2

The combination of alleles one has at a given locus.
Homozygous: Having two of the same allele.
Heterozygous: Having two different alleles.

Question 3

Penetrance:

Answer 3

The proportion of individuals carrying a particular
allele that also express an associated phenotype.

Question 4

Expressivity:

Answer 4

The varying phenotypic outcomes of a genotype

Question 5

Genetic Leakage

Answer 5

: Flow of genes between species via hybrid offspring

Question 6

Genetic Drift:

Answer 6

When the composition of the gene pool changes as a
result of chance.

Question 7

Founder Effect:

Answer 7

Bottlenecks that suddenly isolate a small population;
inbreeding.

Question 8

Taxonomic

Answer 8

Kingdom, phylum, class, order, family, genus, species.
“King Phillip Came Over From Great Spain”

Question 9

Law of Segregation

Answer 9

: An organism has two alleles for each gene, which
segregate during Anaphase I. Because of this,
gametes carry only one allele for a trait.

Question 10

Law of Independent
Assortment

Answer 10

The inheritance of one allele does not influence the
probability of inheriting a given allele for a different
trait (except for linked genes).

Question 11

Griffith:

Answer 11

Demonstrated transformation. Heat-killed smooth
(virulent) strain of bacteria still transformed rough strain
into smooth.

Question 12

Avery-MacLeod-McCarty

Answer 12

Degradation of DNA led to a cessation of bacterial
transformation. Degradation of proteins did not

Question 13

Hershey-Chase:

Answer 13

Confirmed DNA is the genetic material because only
radiolabeled DNA could be found in bacteriophage-infected bacteria

Question 14

Point Mutations:

Answer 14

The substituting of one nucleotide for another.

Question 15

Frameshift Mutations:

Answer 15

Moving the 3 letter reading frame.

Question 16

Recombination
Frequency:

Answer 16

The likelihood of two alleles being separated during
crossing over in meiosis.

Question 17

Hardy-Weinberg
Principle:

Answer 17

If a population meets certain criteria (aimed at a lack
of evolution), then the allele frequencies will remain
constant

Question 18

Hardy-Weinberg
Equation:

Answer 18

P + q = 1

p^2 + 2Pq + q^2 = 1

Question 19

Modern Synthesis Model

Answer 19

Neo-Darwinism. Mutation and recombination are mechanisms of variation. Differential reproduction

Question 20

Inclusive Fitness

Answer 20

If a population meets certain criteria (aimed at a lack of evolution), then the allele frequencies will remain constant.

Question 21

Punctuated Equilibrium

Answer 21

Considers evolution to be a very slow process with intermittent rapid bursts of evolutionary activity.

Question 22

Mode of Natural Selection:

Answer 22

Stabilizing selection

Directional selection

Disruptive selection

Adaptive radiation

Question 23

Stabilizing Selection:

Answer 23

: Keeps phenotypes in a narrow range, excluding extremes.

Question 24

Directional Selection:

Answer 24

Moves the average phenotype toward an extreme.

Question 25

Disruptive Selection:

Answer 25

Moves toward two different phenotypes at the extremes, can lead to speciation

Question 26

Adaptive Radiation

Answer 26

Rapid emergence of multiple species from a common ancestor, each has a niche.

Question 27

Molecular Clock Model:

Answer 27

The degree of difference in the genome between two species is related to the amount of time since the two species broke off from a common ancestor.