How many genotypes are represented only once in the Mendelian dihybrid F2 generation?

Question

How many genotypes are represented only once in the Mendelian dihybrid F2 generation? (A) 2 (B) 3 (C) 6 (D) 4

Tardigrade Admin · Accepted Answer

In Mendelian dihybrid cross homozygous dominant pea plant (Yellow, Round seeds) is crossed with homozygous recessive pea plant (green, wrinkled).
Parental genotype-

(YY RR) \times (yyrr)

The

F_{1}

generation of this cross produces Yellow, Round phenotype pea plant having genotype-

(Y y R r)

In

F_{2}

generation number of progeny formed

= 16

The genotypic ratio of dihybrid cross is -

1 : 2 : 1 : 2 : 4 : 2 : 1 : 2 : 1.

Hence, the genotype which appears only once is -

4

Q. How many genotypes are represented only once in the Mendelian dihybrid $F_{2}$ generation?

$2$

$3$

$6$

$4$

Q. How many genotypes are represented only once in the Mendelian dihybrid F2​ generation?

2

3

6

4

Q. How many genotypes are represented only once in the Mendelian dihybrid $F_{2}$ generation?

$2$

$3$

$6$

$4$