In ant lions the gene for dull teeth is dominant D. The recessive gene d produces sharp teeth . Another gene T, when homozygous , produces dark-brown coats . Its allele t, when homozygous , produces albino coats. The heterozygote Tt is chocolate coloured . If a chocolate coloured , dull toothed male whose father was sharp toothed is mated to a chocolate , sharp -toothed female , what is the probability that an albino , sharp - toothed offspring will be produced ?

Options

A. `8//16`
B. `12//16`
C. `4//16`
D. `2//16`

Explanation

To solve the problem step by step, we will analyze the genetic traits and perform a Punnett square analysis to determine the probability of producing an albino, sharp-toothed offspring.

### Step 1: Identify the Genotypes of the Parents
1. **Male Parent**: The male is chocolate-colored and dull-toothed. Since his father was sharp-toothed (genotype dd), the male must have inherited a recessive allele (d) from his father. Therefore, his genotype for teeth is:
- Dull teeth (dominant D) means he can be either DD or Dd. Since he has a sharp-toothed father, he must be Dd.
- For coat color, being chocolate-colored means he is Tt (heterozygous).
- **Genotype of Male**: Dd Tt

2. **Female Parent**: The female is chocolate-colored and sharp-toothed. Since she is sharp-toothed, her genotype for teeth must be:
- Sharp teeth means she is dd (homozygous recessive).
- For coat color, being chocolate-colored means she is also Tt (heterozygous).
- **Genotype of Female**: dd Tt

### Step 2: Determine the Gametes of Each Parent
- **Male (Dd Tt)** can produce the following gametes:
- DT, Dt, dT, dt

- **Female (dd Tt)** can produce the following gametes:
- dT, dt

### Step 3: Set Up the Punnett Square
We will set up a Punnett square to combine the gametes from both parents.

| | dT | dt |
|---------|----------|----------|
| **DT** | DdTt | Ddtt |
| **Dt** | DdTt | Ddtt |
| **dT** | ddTt | ddtt |
| **dt** | ddTt | ddtt |

### Step 4: Analyze the Offspring Genotypes
From the Punnett square, we can identify the possible genotypes of the offspring:
1. DdTt (chocolate, dull)
2. Ddtt (albino, dull)
3. ddTt (chocolate, sharp)
4. ddtt (albino, sharp)

### Step 5: Determine the Desired Phenotype
We are looking for the probability of producing an albino, sharp-toothed offspring, which corresponds to the genotype:
- **Albino**: tt (homozygous recessive)
- **Sharp-toothed**: dd (homozygous recessive)

From our Punnett square, we see that:
- The genotype ddtt (albino, sharp) appears once.

### Step 6: Calculate the Probability
Out of the total 8 possible offspring genotypes from the Punnett square:
- Only 1 genotype (ddtt) corresponds to the desired phenotype (albino, sharp-toothed).

Thus, the probability of producing an albino, sharp-toothed offspring is:
- **Probability = Number of desired outcomes / Total outcomes = 1/8**

### Final Answer
The probability that an albino, sharp-toothed offspring will be produced is **1/8**.

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