Question

Mendel crossed a homozygous pea plant having round seeds (RR) with a homozygous pea plant having wrinkled seeds (rr). He got different results. On the basis of it, answer the following questions:

1. Which character of seed is studied in the experiment?
2. Which of the above two traits is dominant?
3. Write the phenotype and genotype of F₁ offspring.
4. Mention and state Mendel's law as shown in the above cross.
5. Make a Punnett square for F₂ generation when two plants of F₁ offspring are crossed with each other.
6. Write the phenotypic ratio of F₂ progeny.
7. What will be the genotypic ratio of F₂ offspring?
8. What are the two traits of seed colour ? Also mention which is dominant and recessive?
9. Write the scientific name of the garden pea.
10. Write two main features of the pea plant, due to which Mendel selected it for his hybridisation studies.

Answer 1

1. The experiment is looking at the seed's form.
2. Most prevalent is the round-shaped character.
3. Phenotype: All F₁ offspring have round seeds.
   Genotype: All F₁ offspring have the genotype Rr, representing a heterozygous combination of one dominant allele (R) and one recessive allele (r) for seed shape.
4. Mendel's Law of Dominance: Out of a pair of opposing personalities present together, only one is able to express herself while the other stays repressed.
5. 
   

   	R	r
   R	RR	Rr
   r	Rr	rr

6. Phenotypic ratio : 3 : 1
7. Genotypic ratio : 1 : 2 : 1
8. Yellow and green are the colours of seeds. Green is recessive; yellow is dominant.
9. Pisum Sativum
10. Mendel had chosen garden peas for the following purposes:
    1. There were several variants accessible as different forms of a character.
    2. Varieties were accessible in pure forms that bred true, that is, produced the same type generation after generation.
    3. Normally self-pollinated, removal of the relevant reproductive elements (male stamens and female carpels) of the flower could inhibit self-pollination and could as well be cross-pollinated artificially.
    4. A pea plant has a short lifetime; hence, several generations can be obtained and investigated in less time.