Chapter 7: Evolution and Adaptation

Question 1

The process of evolution depends on ___________ ___________________

Answer 1

Genetic variation

Question 2

Can evolution occur without genetic variation?

Answer 2

No

Question 3

_________________ ________ is a molecule composed of two strands of nucleotides that are wound together into a shape known as a double helix

Answer 3

Deoxyribonucleic acid

Question 4

________________ are compact structures consisting of long strands of DNA wound around proteins

Answer 4

Chromosomes

Question 5

In a ___________ _________ or ____________ distribution, there is a symmetrical distribution of values around the mean

Answer 5

Bell curve

Normal distribution

Question 6

__________________ are alternate forms of a particular gene

Answer 6

Alleles

Question 7

How do new alleles develop?

Answer 7

Via mutation

Question 8

________________ refers to a single trait affects by several genes

Answer 8

Polygenic

Question 9

What is pleiotropy?

Answer 9

When a single gene affects multiple traits

Question 10

________________ refers to a process wherein the expression of one gene controls that of another gene

Answer 10

Epistasis

Question 11

What are three examples of epistasis in humans?

Answer 11

(1) Red hair
(2) Albinism
(3) Alzheimer’s disease

Question 12

________________ refers to an individual who has two different alleles of a particular gene

Answer 12

Heterozygous

Question 13

_______________ refers to an individual who has two identical alleles of a particular gene

Answer 13

Homozygous

Question 14

_____________ arises when two alleles both contribute to a third or blended phenotype

Answer 14

Codominance

Question 15

What’s a common example of codominance?

Answer 15

Pink snapdragons

Question 16

What is a dominant allele?

Answer 16

An allele that masks the expression of the other allele of a given gene

Question 17

What is a recessive allele?

Answer 17

An allele whose expression is masked by the presence of another allele

Question 18

What is a gene pool?

Answer 18

The collection of alleles from all individuals in a population

Question 19

_____________ _______________ is the combination of alleles of those possessed by the diploid parent in a given gamete

Answer 19

Random assortment

Question 20

What is a mutation?

Answer 20

A random change in the sequence of nucleotides in regions of DNA that either comprise a gene or control the expression of a gene

Question 21

__________________ refers to the reshuffling of genes that can occur as DNA is copied during meiosis and chromosomes exchange genetic material

Answer 21

Recombination

Question 22

Recombination can lead to ____________ _____________, which is required for evolution to occur

Answer 22

Genetic variation

Question 23

Evolution can occur at _______________ or through _______________

Answer 23

Random

Selection

Question 24

________________ _____________ is a process that occurs when genetic variation is lost because of random variation in mating, mortality, fecundity, and inheritance

Answer 24

Genetic drift

Question 25

Genetic drift is also called ______________ ______________

Answer 25

Neutral selection

Question 26

Does genetic drift act more strongly on a small or large population?

Answer 26

A small population

Question 27

What is a deme?

Answer 27

A subpopulation, a smaller group within a population, that can freely interbreed

Question 28

What is the bottleneck effect?

Answer 28

A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population and thus a loss of genetic variation due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts or human activities such as genocide and human population planning.

Question 29

What are two ways in which genetic drift may occur?

Answer 29

Bottleneck effect | Founder effect

Question 30

The ____________ _____________ is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population

Answer 30

Founder effect

Question 31

What plant discussed in class spread in the United States as a result of the founder effect?

Answer 31

Eichhornia crassipes | The water hyacinth