Test 1: Evolutionary Change In Populations (Microevolution)

Front 1

Microevolution:
1. Where does it occur?
2. Where is the impact?
3. When does it occur?
4. What is the result?

Back 1

1. At the genetic level
2. frequency of alleles in population change
3. occurs generation to generation
4. Hardy-Weinberg principle not met

Front 2

What processes lead to microevolution?

Back 2

mutations, crossing over, nonrandom mating, gene flow, genetic drift, natural selection

Front 3

Describe mutations (occurrence, results, effect on allele frequency)

Back 3

1. spontaneous
2. permanent, heritable changes in DNA; increases variation
3. small alterations on allele frequency

Front 4

Describe crossing over(occurrence, results, effect on allele frequency)

Back 4

1. meiosis
2. generation variation

Front 5

Describe nonrandom mating

Back 5

1. mate selection - based on phenotypes
2. inbreeding alters variation in gene pool (decreases it)
3. allele frequencies tend to be the same
4. heterzygotes decrease, whie homozygotes increase
5. genetic fitness decreases
6. selective breeding (animals tend to breed with similar animals ex: chihuahuas and Great Danes)

Front 6

Describe gene flow

Back 6

1. provides genetic variability by introducing new genes
2. helps maintain diversity
3. counteracts the effect on natural selection and gene drft

Front 7

Describe genetic drift

Back 7

1. random occurrence
2. these events effect allele frequency
3. Decreases variation, may cause harmful alleles to become fixed
4. Bottle nose and Founder effects

Front 8

Describe the bottle neck effect

Back 8

1. caused by natural disasters or overhunting
2. causes rapid decline in population
3. alters allele frequency, increase genetic homogeneity

Front 9

Describe the Founder effect.

Back 9

1. small number of individuals found a new colony
2. have to be an isolated population
3. loss of genetic variation
4. may be distinctly different from parent population

Front 10

What are the types of natural selection/

Back 10

stabilizing selection, directional selection, disruptive selection

Front 11

What is stabilizing selection?

Back 11

1. influenced by stabilizing forces most of the time
2. favored phenotypes: average
3. bell curve narrows
4. not much variation

Front 12

What is directional selection?

Back 12

1. Environment changes over time
2. favored phenotypes: one of the extremes
3. one of phenotypes gradually replaces another

Front 13

What is disruptive selection?

Back 13

1. Extreme environmental changes
2. favored phenotypes: two or more phenotypes
3. trend in several directions

Front 14

Maintenance of genetic variation

Back 14

1. balanced genetic polymorphism
2. Neutral variation
3. Heterozygote advantage
4. Frequency dependent selection
5. Cline

Front 15

Describe genetic polymorphism

Back 15

maintaining 2 or more alleles for at traits

Front 16

Describe neutral variation

Back 16

mutation has not ultimate impact of on survival and reproduction; way to maintain genetic variability

Front 17

Describe heterozygote advantage

Back 17

has a higher degree of fitness

Front 18

What is frequency dependent selection?

Back 18

fitness depends on how frequently it appears in the populations; lose advantage as it becomes more common

Front 19

What is cline?

Back 19

Gradual change in phenotype and genotype frequencies through a series of geographically separate populations as result of population gradient