evolution of life d4.1(natural selection)

Question 1

how does natural selection link to evolution?

Answer 1

variation occurs within a population -overproduction, struggle for resources, survival of the fittest(traits are advantageous) - frequency with favourable variation increases

Question 2

what causes genetic variation?

Answer 2

mutations, sexual reproduction

Question 3

what causes mutations?

Answer 3

errors in copying genes during dna replication

Question 4

how does sexual reproduction introduce genetic variation into a population?

Answer 4

gametes crossover + assortment of homologous chromosomes

Question 5

and what does this lead to?

Answer 5

unique allele arrangements/combinations

Question 6

what are the five limiting factors?

Answer 6

food, water, shelter, space, mates

Question 7

what is differential reproduction?

Answer 7

some organisms have favourable traits compared to others; they create more offspring to pass on the traits

Question 8

what are selection pressures?

Answer 8

factors that lead to differential survival or reproduction, thus causing a change in genetic composition

Question 9

what are density dependent factors?

Answer 9

factors that affect population size and are dependent on population density

Question 10

what are the factors that determine biological fitness?

Answer 10

environment, fitness of individual, survival value, reproductive potential, capacity to produce offspring

Question 11

what is intraspecific competition, and what are some examples?

Answer 11

competition within a species; two trees competing for sunlight, and water

Question 12

what is sexual selection?

Answer 12

preferences for finding a mate

Question 13

what are the differences between intrasexual and intersexual selection?

Answer 13

intrasexual selection refers to competition between the same sex, while intersexual is competiton between different sexes