dihybrid inheritance

Question 1

what is dony dihybrid inheritance?

Answer 1

inheritance of two characteristics that are controlled by awperate genes e.g
G= green coloured seeds g=yellow coloured seeds R= allele for round shaped seeds r= wrinkled shaped seeds

Question 2

example of dihybrid inheritance

Answer 2

mendel investigated inheritance of two characteristics of a pea plant at the same time. These were:
• seed shape- round dominant
• seed colour yellow dominant

Question 3

what two pure breeding types did mendel cross?

Answer 3

•one always producing round shaped yellow coloured seeds RRGG
• one always producing wrinkled shapes green coloured seeds rrgg

Question 4

what were the characteristics of the F1 generation

Answer 4

• 100% heterozygous
• genotypes RrGg
• phenotypes round and yellow

Question 5

what types of gamete can be produced from the F1 generation and why?

Answer 5

• RG, Rg, rG, rg
• the gene for seed colour and the gene for seed shape are on separate chromosomes
• as chromosomes arrange themselves at random on the equator during meiosis and one of the two alleles of the gene for seed colour can combine with any one of the alleles for seed shape
• fertilisation also random so any of the 4 gametes of one plant can combine with any of the 4 of another plant

Question 6

what are the offspring’s phenotypes (F2)

Answer 6

9 round yellow seeds
3 round green seeds
3 wrinkled yellow seeds
1 stinker green seed

Question 7

law of independent assortment

Answer 7

each member of a pair of alleles may combine randomly with either of another pair