Vocabulary

Question 1

Genes

Answer 1

A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses) that controls a .

Question 2

Allele

Answer 2

Any of the alternative versions of a gene occupying a specific locus on that may produce distinguishable phenotypic effects.

Question 3

Genotype

Answer 3

The genetic makeup, constitution, or set of alleles, of an organism.

Question 4

Phenotype

Answer 4

The observable physical and physiological traits of an organism, which are determined by its genetic makeup.

Question 5

Fitness

Answer 5

Reproductive success and reflects how well an organism is adapted to its environment.

Question 6

Adaptation

Answer 6

Inherited characteristic of an organism that enhances its survival and reproduction in a specific environment.

Question 7

Homologous Structures

Answer 7

A similarity in biological structures due to common ancestry.

Question 8

Artificial Selection

Answer 8

Selection in breeding exercises, carried
out deliberately, by humans to encourage the propogate of desirable genetic traits.

Question 9

Typological thinking vs population thinking

Answer 9

For the typologist, the type (eidos) is real and the variation an illusion, while for the populationist the type (average) is an abstraction and only the variation is real. Typological thinking porpogated the idea that all animals were created perfectly.

Question 10

Acclimation

Answer 10

Acclimation refers to a physiological change in an individual stimulated by exposure to a different, often stressful, environment.

Question 11

Vestigial

Answer 11

A feature of an organism that is a historical remnant of a structure that served a function in the organism’s ancestors.

Question 12

Trade-offs

Question 13

Genetic variation

Answer 13

Differences among individuals in the composition of their genes (frequency of alleles) or other DNA segments.

Question 14

Fixed allele vs lost allele

Question 15

Homozygous vs heterozygous

Answer 15

Heterozygous: having two different alleles of a gene

Homozygous: having two identical alleles of a gene

Question 16

Positive vs negative selection

Answer 16

Positive Selection: Natural selection that increases the frequency of an advantageous allele is called positive selection (sometimes referred to Darwinian selection)

Negative Selection: Natural selection that decreases the frequency of a deleterious allele is called negative selection (also called purifying selection)

Question 17

Directional, stabilizing, disruptive, and balancing selection

Answer 17

Question 18

What is Genetic Drift?

Answer 18

Genetic drift is any change in allele frequencies in a population due to chance.

It Generally affects smaller populations because smaller sample sizes are not likely to produce results similar to those that follow the law of large counts.

Question 19

What is the founder effect, and how does it relate to genetic drift?

Answer 19

A founder effect occurs when a group of individuals establishes a new population in a new area. Allele frequencies likely differ from the source population if the new population is small enough.

Founder effects are especially common in the colonization of isolated habitats like islands.

Question 20

What is a population bottleneck, and how does it relate to genetic drift?

Answer 20

A sudden decrease in population size in a large population is called a population bottleneck.

Population bottlenecks lead to genetic bottlenecks—a sudden reduction in the number of alleles in a population
Genetic drift occurs during genetic bottlenecks and causes a change in allele frequencies.

Question 21

Gene Flow

Answer 21

Gene Flow is the movement of alleles between populations

• occurs when individuals leave one population, join another, and breed.
• Gene flow equalizes allele frequencies between the source and recipient populations.
  • Gene flow homogenized allele frequencies or reduces genetic differences between populations.