genetic variation and diversity

Question 1

define genetic variation

Answer 1

the differences between individuals in a population - due to different allele combinations producing different phenotype traits

Question 2

what environmental factors increase genetic variation

Answer 2

• intensity of light
• availability of food and water
• climate

Question 3

what genetic factors produce and increase genetic variation

Answer 3

mutations and gene flow

Question 4

describe how mutations increase genetic variation

Answer 4

changes to the DNA base sequence can produce new versions of genes, alleles which can be passed down to offspring

Question 5

describe how gene flow increases genetic variation

Answer 5

this is the movement of alleles between populations which introduces new alleles leading to a wider range of traits cc r4r

Question 6

how can meiosis increase genetic variation

Answer 6

• crossing over
• independent segregation
• random fertilisation

Question 7

what happens during random fertilisation and how does this increase genetic variation

Answer 7

sexual reproduction is the fusion of gametes, any two gametes can fuse and therefore different chromosome combinations are created

Question 8

explain crossing over and how it increases genetic variation

Answer 8

chromatids on a homologous pair of chromosomes twist around each other during prophase I to form chiasmata

they break off during anaphase I as the homologous chromosomes split

this creates different allele combinations

Question 9

explain independent segregation and how it increases genetic variation

Answer 9

when the second nuclear division occurs, the chromatids are seperated into random combinations to form 4 haploid daughter cells which are genetically different