Genotype and Phenotype

Which one of the following genotypes is homozygous dominant and which one homozygous recessive in regards to tongue rolling:

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.

Distinguish between the following pair:

Homozygous and Heterozygous chromosomes

In a certain species of animals, black fur (B) is dominant over brown fur (b) Predict the genotype and phenotype of the offspring when both parents are ‘Bb’ or have heterozygous
black fur . 

The physical expression of a character is called ______.

A homozygous plant having round (R) and yellow (Y) seeds is crossed with another homozygous plant having wrinkled (r) and green (y) seeds. Answer the following questions:

1. Give the genotype of the F₁ generation.
2. Mention the phenotype of the F₁ offspring.
3. Give the possible combinations of gametes that can be obtained from F₁ hybrids.
4. Give the dihybrid phenotypic ratio and the phenotype of the offspring of the F₂ generation when two plants of F₁ generation are crossed.
5. Name and state the law which explains the dihybrid phenotypic ratio.