inheritance

Question 1

when would you use a monohybrid cross

Answer 1

when looking at one characteristic determined by one gene e.g breeding of a tall plant and dwarf plant (tt v TT)

Question 2

what is codominance

Answer 2

• allele of a gene interact so complete dominance is lacking
• both alleles are expressed
• heterozyg phentotype is diff from homo dom and recc
• e.g homo will be red or white flower and het will be pink
• use capital letter and supscript to represent alleles

Question 3

what is sex linked inheritance

Answer 3

• when a gene is located on one of the sex chromosomes (normally x)

Question 4

when would you use a dihybrid cross

Answer 4

• a characteristic determined by two genes

Question 5

what is epistasis

Answer 5

• the interaction of 2 diff genes in terms of producing a phentotype
• e.g colourless compound one gene codes for enz w causing yellow compound one codes for enzyme y causing orange compond

Question 6

what is autosomal linkage

Answer 6

• if 2 genes occur on same chromosome are linked and so alleles are limited
• only one homologous pair is needed if all alleles are to be present