The possibility of a female becoming haemophilic is extremely rare because mother of such a female has to be at least `overset("(i)") "____"` and father should be `overset("(ii)") "____"`

Options

A. (i) haemophilic, (ii) carrier
B. (i) carrier, (ii) haemophilic
C. (i) haemophilic, (ii) normal
D. (i) haemophilic, (ii) haemophilic

Explanation

To solve the question regarding the rarity of a female becoming hemophilic, we need to understand the genetics behind hemophilia, which is an X-linked recessive disorder. Here’s a step-by-step breakdown of the solution:

### Step 1: Understanding Hemophilia
Hemophilia is a genetic disorder caused by the deficiency of clotting factors in the blood, leading to excessive bleeding. It is primarily inherited in an X-linked recessive manner.

**Hint:** Recall that X-linked recessive disorders predominantly affect males, as they have only one X chromosome.

### Step 2: Genetic Composition of Males and Females
- Males have one X and one Y chromosome (XY).
- Females have two X chromosomes (XX).

**Hint:** Remember that males express the trait if their single X chromosome carries the hemophilia gene, while females need both X chromosomes to carry the gene to express the disorder.

### Step 3: Conditions for a Female to be Hemophilic
For a female to be hemophilic, she must inherit two copies of the hemophilia allele (one from each parent). This means:
- The mother must contribute one X chromosome with the hemophilia gene.
- The father must provide the other X chromosome, which will also carry the hemophilia gene since he has only one X chromosome.

**Hint:** Think about how traits are inherited from both parents and the necessity of receiving the same trait from both sides for females.

### Step 4: Determining the Mother's Genotype
For the mother to pass on the hemophilia gene, she must be at least a carrier (X^hX), where X^h represents the X chromosome with the hemophilia allele. If she were normal (XX), she could not pass on the hemophilia allele.

**Hint:** A carrier has one normal X chromosome and one affected X chromosome, allowing her to pass on the disorder without being affected herself.

### Step 5: Determining the Father's Genotype
The father must be hemophilic (X^hY) because he has only one X chromosome. If he were normal (XY), he would not be able to pass on the hemophilia allele.

**Hint:** Since males have only one X chromosome, if that X carries the hemophilia gene, they will express the disorder.

### Final Answer
Thus, the answers to fill in the blanks are:
- (i) **carrier** (the mother must be a carrier)
- (ii) **hemophilic** (the father must be hemophilic)

### Summary
The possibility of a female becoming hemophilic is extremely rare because the mother of such a female has to be at least **carrier** and the father should be **hemophilic**.