D4.1 Natural Selection

Question 1

Natural selection causes

Answer 1

Overproduction of offspring, variation, and reproduction between genetically diverse parents

Question 2

Selection pressure

Answer 2

Pressures influencing reproduction

Question 3

Density dependent factors

Answer 3

Factors dependent on the density of a population -> food

Question 4

Density independent factors

Answer 4

Pressures not dependent on the density of a population -> climate

Question 5

Biological fitness

Answer 5

Ability of an organism to reproduce & pass on genetics

Question 6

Intraspecific competition

Answer 6

Same species compete for resources & mates

Question 7

Interspecific competition

Answer 7

Different species compete for resources

Question 8

Sexual dimorphism

Answer 8

When sex’s of the same species look different

Question 9

Gene pool

Answer 9

Sum of all the alleles present in a population

Question 10

Allele frequency

Answer 10

Frequency of allele in a population
Allele freq. = # of copies of x in pop./total # of genes in a pop.

Question 11

Genetic drift

Answer 11

Random event altering gene frequencies.

Question 12

Stabilizing selection

Answer 12

Favors average individuals over extremes -> leads to individuals looking the same

Question 13

Directional selection

Answer 13

One extremes is favored

Question 14

Disruptive selection

Answer 14

Both extremes are favored -> may lead to formation of a new species

Question 15

Hardy Weinberg equation

Answer 15

calculates the genetic variation of a population at equilibrium