natural & artificial selection (7.2)

Question 1

natural selection- what is it? & more about it.

Answer 1

it is… the process that results when the characteristics of a population of organisms changes over many generations.
change happens because individuals survive environmental conditions and pass their allels on to their offspring.
for natural selection to occur, there must be diversity within a species.

Question 2

selective pressure- what is it?

Answer 2

it is… environmental conditions that select for certain characteristics of individuals and select against other characteristics

Question 3

natural selection is situational

Answer 3

this selection has no purpose, no direction.
traits that at one time, seem to have no advantage to survival, may become beneficial as the environment changes

Question 4

artificial selection- what is it?

Answer 4

it is… selective pressure exerted by humans on populations in order to improve or modify particular desirable traits. not only in food- all crops have been artificially selected for high yield.

Question 5

food crops

Answer 5

food crops that form most of our diets (rice, corn, wheat) are the result of artifiical selection.
ex: wild mustard has been bred to create many common food crops such as…
-kale
-broccoli
-brussel sprouts

Question 6

concequences of artificial selection

Answer 6

there are some negative concequences to this selection.
ex: English bull dogs…
-bred for flat faces, have severe respiratory problems