variations

Question 1

what is continuous variation?

Answer 1

-represented by histogram
-influenced by environment
-controlled by many genes

Question 2

what is discontinuous variation?

Answer 2

-represented by bar chart
-not influenced by environment
-controlled by a single pair of genes

Question 3

what is mutations?

Answer 3

-spontaneous change in either gene structure or change in chromosome number
-may be inheritable, if in gametes
-may be lethal/harmful
-may be beneficial

Question 4

what is mutagens?

Answer 4

-agents that cause mutations
-caused by mustard gas

Question 5

what are chromosomal mutations caused by?

Answer 5

-nondisjunction during gamete formation
-homologous chromosomes pair fail to separate during meiosis
-higher age of mother, higher risk

Question 5

what is chromosomal mutations?

Answer 5

-change in chromosome number
-e.g. down syndrome, extra cope of chromosome 21

Question 6

what is gene mutations?

Answer 6

• change in nucleotide base in gene sequence to produce different protein
  -dominant mutations easily detected
  -recessive mutations not detectable
  -e.g. albinism

Question 7

what is the format for natural selection?

Answer 7

-spontaneous mutations result in variation in the population, some have…..others have…..
-due to selection pressure, organisms that have….are at selective advantage as they can….
-hence, they survive and reproduce, passing on the beneficial gene to the offspring, while the other organisms die
-overtime, population of organisms with…..increases.