Question

A plant with green coloured (yy) and round-shaped (RR) seeds was crossed
with another plant having yellow coloured (YY) and wrinkled (rr) seeds. In
F1, all the progenies were round-shaped and yellow coloured. Answer the
following questions with respect to Mendelian principles of inheritance:
If a total of 320 progenies are obtained in F2 generation, how many of them
will have yellow coloured and round shaped seeds?
A. 20
B. 60
C. 140
D. 180​

Answer 1

Answer:

Explanation:

i) Pisum sativum is the scientific name of a pea plant.

ii) The genotype of the F  

1

​  

 generation is RrYy.

iii) The phenotypic ratio of F  

2

​  

 generation is 9:3:3:1 where phenotypes of offsprings are - Round and Yellow, Round and green, Wrinkled and yellow and Wrinkled and green.

iv) According to Mendel's law of independent assortment, during the inheritance of two or more characters, the assortment of individual traits takes place independently during gamete formation. Thus each allele of a pair segregates independently and each gamete formed contains one allele of that trait.  

v) F  

1

​  

 genotype is RrYy. So, the possible gamete combinations are

1. RY= Round yellow

2. rY = Wrinkled yellow

3. Ry= Round green

4. ry = Wrinkled green

c)140