Unit 8- Evolution

Question 1

Adaptation

Answer 1

an anatomical, physiological or behavioral inherited trait which enhances or increases survival and/or reproductive rates. This trait can be passed onto their offspring

Question 2

Bottleneck Effect

Answer 2

It occurs when a population experiences a sudden, dramatic decrease that leaves only a few individuals alive. Certain alleles may be overrepresented among the survivors while some may be less represented or absent. This is all by chance.

Question 3

Directional selection

Answer 3

Directional selection shifts overall makeup of the population by acting against individuals at one of the phenotypic extremes. Ex: Insects exposed to pesticides, darker fur color of rats. The environment determines the selectivity of a population

Question 4

Disruptive selection

Answer 4

environmental conditions are varied in a way that favors individuals at BOTH extremes of a phenotypic range. Ex: light and dark fur of rats have the highest population

Question 5

Evolution

Answer 5

species adapt over time in which species adapt over time in response to their changing environment

Question 6

Fitness

Answer 6

the ability for organisms to survive and reproduce in the environment in which they find themselves

Question 7

Gene Flow

Answer 7

Transfer of alleles into or out of a population due to the movement or fertile individuals/ their gametes. Can be positive and negative results. Beneficial alleles can be transferred to new populations.

Question 8

gene pool

Answer 8

all the different alleles and possible genotypes/phenotypes in a certain population

Question 9

genetic drift

Answer 9

A chance event that alters allele frequencies. Chance events will cause allele frequencies to fluctuate unpredictably. This is significant in small populations.

Question 10

Hardy-Weinberg Equilibrium

Answer 10

p^2+2pq+q^2

Question 11

homologous structures

Answer 11

Organs or structures that organisms share which demonstrates descent from a common ancestor, a form of divergent evolution

Question 12

Microevolution

Answer 12

It is a change in allele frequencies in a population over generations

Question 13

natural selection

Answer 13

consistently improves the match between organisms and their environment.

Question 14

Population

Answer 14

all the participants in a certain group

Question 15

stabilizing selection

Answer 15

favors intermediate phenotypes, in relatively stable environment. Conditions tend to reduce phenotypic variations.

Question 16

vestigial structures

Answer 16

organs or structures that no longer have purpose in the current oroganism. Finger bones in whales and aquatic mammals