B11.4

Question 1

Define variation

Answer 1

differences between individuals of the same species

Question 2

what is the difference between phenoypic variation and genetic variation?

Answer 2

phenotypic variation - affected by genetics and environment
genetic variation - all result of mutation

Question 3

describe continuous variation

Answer 3

range of phenotypes between two extremes

Question 4

describe discontinuous variation

Answer 4

-limited number of phenotypes with no intermediates
-mostly caused by genes alone

Question 5

define mutation

Answer 5

a change in a gene or chromosome

Question 6

what increases the rate of mutation?

Answer 6

-ionising radiation
-some chemicals

Question 7

describe natural selection [6]

Answer 7

-variation
-production of offspring
-competition for resource
-struggle for survival
-reproduction by better adapted individuals to the environment
-passing of of their alleles to the next generation

Question 8

describe evolution

Answer 8

the change in adaptive features of a population over time as the result of natural selection

Question 9

define adaptation

Answer 9

-the process resulting from natural selection
-populations become more suited to their environment over many generations

Question 10

describe an example of evolution by natural selection

Answer 10

development of strains of antibiotic resistant bacteria

Question 11

describe selective breeding

Answer 11

-choosing individuals with desirable characteristics
-crossing of these individuals
-choosing offsprings with desirable characteristics and breeding them
-repitition until most of the population has the desirable characteristics

Question 12

what is the difference between natural and artificial selection

Answer 12

natural - to adapt to its surroundings and increase chance of survivability
artificial - imposed by an external entity to enhance the frequency of desirable features