132017 Genetics Problems 1 Round shape is dominant to wrinkl

1/3/2017 Genetics Problems 1. Round shape is dominant to wrinkled. Yellow pea color is dominant to green. Purple flowers are dominant to white. If Mendel crossed a round green pea plant with purple flowers to a wrinkled yellow pea plant with white flowers and got at least some of each possible genotype, what were the genotypes of each parent and if he counted 1000 progeny, how many round yellow peas should he expect? How many wrinkled green peas with purple flowers? 2. In an individual with Aa BB Cc dd Ee alleles, assuming independent assortment, how many different gametes are possible?

Solution

Dominant: Round (R) shape, yellow (Y) color, purple (P) flower

Recessive: wrinkled (r), green (y) pea color, white(p) flower

Cross between

Round green purple RryyPp      x rrYypp wrinkled yellow white

Gametes

rYp

ryp

RyP

RrYyPp   Round Yellow Purple

RryyPp    Round Green Purple

Ryp

RrYypp   Round Yellow White

Rryypp   Round Green White

ryP

rrYyPp    Wrinkled Yellow Purple

rryyPp   Wrinkled Green Purple

ryp

rrYypp    Wrinkled Yellow White

rryypp Wrinkled Green White

Round yellow genotypes are = 2 in 8 genotypes so percentage of having the trait is =

2/8 x 100 =25%; so the number of progenies are 1000 x 25% = 250

Wrinkled Green Purple genotypes are = 1 in 8 so percentage of having the trait is =

1/8 x 100 = 12.5%; so the number of progenies are 1000 x 12.5%; = 125

Number of gametes depends upon heterozygous alleles. This is calculated by the formula (number of heterozygote)²

For AaBBCcddEe ; total number of heterozygote alleles= 3

so the Number of gametes are = 3² = 9

Gametes	rYp	ryp
RyP	RrYyPp   Round Yellow Purple	RryyPp    Round Green Purple
Ryp	RrYypp   Round Yellow White	Rryypp   Round Green White
ryP	rrYyPp    Wrinkled Yellow Purple	rryyPp   Wrinkled Green Purple
ryp	rrYypp    Wrinkled Yellow White	rryypp Wrinkled Green White