**Q.5. Work out the probabilities of the off-springs in a case when heterozygous tall hybrids of F1 generation are self-fertilized.**

When heterozygous tall hybrids of the F1 generation are self-fertilized, the offspring will have a mixture of both homozygous tall and heterozygous tall plants. This is because the heterozygous tall hybrids have one dominant allele for tallness (T) and one recessive allele for shortness (t).

To determine the probabilities of the offspring, we can use a Punnett square. In this case, we will use the following genotypes:

- Homozygous tall (TT)
- Heterozygous tall (Tt)
- Homozygous short (tt)

The Punnett square for the self-fertilization of heterozygous tall hybrids would look like this:

```
T t
T TT Tt
t Tt tt
```

From the Punnett square, we can see that there are three possible genotypes in the offspring: TT, Tt, and tt.

The probability of getting a homozygous tall plant (TT) is 1/4 or 25% because there is only one TT genotype out of the four possible combinations.

The probability of getting a heterozygous tall plant (Tt) is also 1/4 or 25% because there is one Tt genotype.

The probability of getting a homozygous short plant (tt) is 1/4 or 25% because there is one tt genotype.

Therefore, the probabilities of the offspring in this case are:

- Homozygous tall (TT): 25%
- Heterozygous tall (Tt): 25%
- Homozygous short (tt): 25%

**Q.6. What will be the result in F1 generation when a homozygous white male rabbit is crossed with a homozygous black female rabbit?**

When a homozygous white male rabbit (WW) is crossed with a homozygous black female rabbit (BB), the result in the F1 generation will be hybrid offspring with a genotype of WwBb.

In this case, the white color (W) and black color (B) are both dominant traits, while the lowercase letters represent the recessive alleles.

Since both parents are homozygous for their respective traits, all the offspring in the F1 generation will be heterozygous for both traits.

Therefore, all the offspring in the F1 generation will have a genotype of WwBb.

**Q.7. How can we produce such seeds which, when sown, yield pink-colored Four O’ clock plants? Explain in detail.**

To produce seeds that yield pink-colored Four O'clock plants, we need to understand the principles of genetic inheritance and the traits that determine flower color in Four O'clock plants.

Four O'clock plants have two alleles for flower color: red (R) and white (r). The red color is dominant, while the white color is recessive. To produce pink-colored flowers, we need to create a hybrid plant that carries one red allele and one white allele.

Here is a step-by-step explanation of how we can achieve this:

1. Select a red