Chapter 17/18 Evolution

Question 0

Is genetic drift caused by chance or does it occur to help a species survival and reproduction rates?

Answer 0

It is random

Question 1

Does natural selection improve or worsen chances of survival and reproduction?

Answer 1

Improves

Question 2

Homologous

Answer 2

a characteristic shared by two groups of organisms because of their descent from a common ancestor.

Question 3

Convergent evolution

Answer 3

occurs when natural selection causes distantly related organisms to evolve similar structures in response to similar environmental challenges.

Question 4

How is the theory of evolution of supported?

Answer 4

6 lines of evidence:

fossils
traces of evolutionary history existing in organisms
similarities and divergences in DNA
direct observations of genetic change in populations
continental drift
the present-day formation of new species.

Question 5

Analogous

Answer 5

a characteristic shared by two groups of organisms because of convergent evolution, not common descent.

Question 6

Artificial selection

Answer 6

a process in which only individuals that possess certain characteristics are allowed to breed. (Crop plants, animals)

Question 7

three types of natural selection

Answer 7

Directional
Stabilizing
Disruptive

Question 8

Directional selection

Answer 8

individuals with one extreme of an inherited characteristic have an advantage over other individuals in the population

Question 9

Example of directional selection

Answer 9

large individuals produce more offspring than do small and medium-sized individuals.

Question 10

Stabilizing selection

Answer 10

individuals with intermediate values of an inherited characteristic have an advantage over other individuals in the population

Question 11

Example of stabilizing selection

Answer 11

medium-sized individuals produce offspring at a higher rate than do small or large individuals.

Question 12

Disruptive selection

Answer 12

individuals with either extreme of an inherited characteristic have an advantage over individuals with an intermediate phenotype (physical characteristic)

Question 13

Example of disruptive selection

Answer 13

both small and large individuals produce more offspring than do medium-sized individuals.

Question 14

What are the four mechanisms that cause populations to evolve?

Answer 14

Mutation
Gene flow
Genetic drift
Natural selection

Question 15

how are new alleles generated?

Answer 15

through mutation

Question 16

Mutation

Answer 16

Change in the sequence of any segment of DNA

Question 17

Gene flow

Answer 17

Exchange of alleles between different populations

Question 18

Genetic drift

Answer 18

natural process in which chance events cause certain alleles to increase or decrease in a population. The genetic makeup of a population undergoing genetic drift changes at random over time

Question 19

Natural selection

Answer 19

evolutionary mechs in which individuals in a population that possess certain inherited characteristics survive and reproduce at a higher rate than other individuals in the population because those characteristics enable the individuals to function optimally in their particular habitat.

Question 20

Shared inherited characteristics

Answer 20

homologous (similar) structures

vestigial organs

Question 21

Shared noninherited characteristics

Answer 21

features on two different organisms with similar function, but no common ancestor

convergent evolution

Question 22

genetic bottleneck

Answer 22

drop in population that causes low genetic variation or a harmful alleles to reach a frequency of 100%

Question 23

Founder effect

Answer 23

drop in size of population from when a small group from a larger population establishes a new population far from its original population