Unit 2: Evolution

Question 1

What is Darwin’s Theory?

Answer 1

Species grow to be more and more different from their ancestors because of their adaptation to their environment.

Question 2

What is Lamarck’s Theory?

Answer 2

Acquired characteristics from an animal can be passed on to their offspring.

Question 3

What is an Adaptation?

Answer 3

An inherited skill of an animal that enhances survival and fitness.

Question 4

What is Natural Selection?

Answer 4

Individuals with more favorable phenotypes are more likely to survive and produce more offspring, thus passing traits to subsequent generations.

Question 5

What is a mutation?

Answer 5

They are always a change in an organism’s DNA.

Question 6

What is Artificial Selection?

Answer 6

Choosing mutations to better accommodate those using it (Humans with crops).

Question 7

What is a Homologous Structure?

Answer 7

A structure that is similar to another due to shared ancestry.

Question 8

What evidence is there to support evolution?

Answer 8

Fossil record, Anatomical record, Molecular record, and Artificial Selection.

Question 9

What is an Analogous Structure?

Answer 9

A characteristic that is similar to another because of convergent evolution.

Question 10

What is Convergent Evolution?

Answer 10

When species evolved independently from different ancestors.

Question 11

What is Divergent Evolution?

Answer 11

When species evolved from a common ancient ancestor.

Question 12

What is a Vestigial Structure?

Answer 12

A body part or function that served a function/purpose in the organism’s ancestry (Appendix).

Question 13

What is a Phenotype?

Answer 13

A trait of an organism.

Question 14

What is a Genotype?

Answer 14

An allele.

Question 15

What is a Gamete?

Answer 15

A sexual cell.

Question 16

What is Meiosis?

Answer 16

Sex cell division.

Question 17

What is Mitosis?

Answer 17

Normal cell division.

Question 18

What is Microevolution?

Answer 18

The smallest scale of evolution, mostly changes in the allele frequencies in a population over generations.

Question 19

What is the Hardy-Weinberg Principle?

Answer 19

The frequencies of genotypes & alleles stay constant in a population from generation to generation.

Question 20

What is Genetic Drift?

Answer 20

A fluctuation of allele frequencies over time RANDOMLY. Occurs most frequently in small populations.

Question 21

What is the Founder Effect?

Answer 21

An isolated population comprised of animals from a larger population. They have their own gene pool.

Question 22

What is the Bottleneck Effect?

Answer 22

Genetic Drift caused caused by a huge chunk of the population being wiped out, like a natural distaster.

Question 23

What is Gene Flow?

Answer 23

Allele transfer from one population to another because of movement of fertile individuals or their gametes.

Question 24

What is Directional Selection?

Answer 24

Natural Selection that allows individuals at one end of the phenotype range to survive or reproduce more successfully then do other individuals.

Question 25

What is Disruptive Selection?

Answer 25

Individuals on both extremes of a phenotype range survive/reproduce better than shorter ranged individuals.

Question 26

What is Stabilizing Selection?

Answer 26

Opposite of Disruptive, closer is better than extreme.

Question 27

What is Sexual Selection?

Answer 27

When a species prefer mates based off of characteristics.

Question 28

What is Heterozygote advantage?

Answer 28

Better reproduction of heterozygotes compared to homozygotes; preserve variation in a gene pool.

Question 29

What 5 conditions that must be met for a population to attain Hardy-Weinberg equilibrium?

Answer 29

1. No mutations 2. Random mating 3. No natural selection 4. Extremely large population size 5. No gene flow

Question 30

What is Macroevolution?

Answer 30

Large changes found in evolution, usually visual changes like a change in color.

Question 31

What is Speciation?

Answer 31

The process of one species splitting into two.

Question 32

What is a Prezygotic Barrier?

Answer 32

A barrier that occurs before the zygotes meet to prevent two different species from having offspring.

Question 33

What is a Postzygotic Barrier?

Answer 33

A barrier that occurs after the zygotes meet to prevent two different species from having offspring.

Question 34

What is Allopatric Speciation?

Answer 34

When a population is geographically isolated into subpopulations.

Question 35

What is Sympatric Speciation?

Answer 35

Speciation occurs in populations that live in the same geographic area.

Question 36

What is Polyploidy?

Answer 36

A condition where a species gains an extra chromosome.

Question 37

What is Habitat Isolation?

Answer 37

A prezygotic barrier that separates species by assigning them a habitat and never giving them a real reason to leave.

Question 38

What is Temporal Isolation?

Answer 38

A prezygotic barrier that separates species by giving them different times of breeding/mating, such as one species being nocturnal or migration.

Question 39

What is Behavioral Isolation?

Answer 39

A prezygotic barrier that separates species by giving them courtship rituals and the ability to recognize their mates.

Question 40

What is Mechanical Isolation?

Answer 40

A prezygotic barrier that prevents successful mating due to morphological differences (physical incompatibility).

Question 41

What is Gametic Isolation?

Answer 41

A prezygotic barrier that prevents successful mating due to gamete incompatibility (sperm cannot fertilize egg, sperm cannot survive female reproductive tract).

Question 42

What is Reduced Hybrid Viability?

Answer 42

A postzygotic barrier that puts the offspring at a disadvantage due to the genes of one or both parents.

Question 43

What is Reduced Hybrid Fertility?

Answer 43

A postzygotic barrier that makes the hybrid offspring sterile, meaning they are unable to have offspring of their own. Example: Mules

Question 44

What is Hybrid Breakdown?

Answer 44

A postzygotic barrier that essentially breaks down the offspring of hybrids over time both physically and genetically to make them eventually too feeble to survive or sterile to prevent more hybrid offspring.

Question 45

What is Punctuated Equilibrium?

Answer 45

Speciation that happens in small periods of sudden change over a long period of time.