Two genes a and b are linked and show 30% recombination. If
++ / ++ individual married with ab / ab then the types and
proportion of gametes in F1 will be -

Options

A. `++ 35% : ab : 35% : + a 15% : +b 15%`
B. `++ 15% : ab : 15% : + a 35% : +b 35%`
C. `++ 35% : ab : 15% : + a 35% : +b 15%`
D. `++ 15% : ab : 35% : + a 15% : +b 35%`

Answer

To solve the question regarding the types and proportions of gametes in the F1 generation when two linked genes A and B show 30% recombination, we can follow these steps:

### Step 1: Understand the Recombination Frequency
The recombination frequency (RF) is given as 30%. This means that 30% of the gametes will be recombinant types, while the remaining 70% will be parental types.

**Hint:** Recombination frequency helps determine how many offspring will show new combinations of alleles.

### Step 2: Determine Parental and Recombinant Gametes
Since the genes are linked, the parental gametes will be the ones that are not recombined. In this case:
- Parental gametes: ++ and AB
- Recombinant gametes: +A and +B

**Hint:** Parental gametes are those that retain the original combinations of alleles, while recombinant gametes are formed due to crossing over.

### Step 3: Calculate the Proportions of Gametes
Given the recombination frequency of 30%, we can calculate the proportions of the gametes:
- Parental gametes (70% total):
- ++ = 35%
- AB = 35%
- Recombinant gametes (30% total):
- +A = 15%
- +B = 15%

**Hint:** The total percentage of parental gametes must equal 70%, and the total percentage of recombinant gametes must equal 30%.

### Step 4: Summarize the Gamete Types and Proportions
Now we can summarize the types and proportions of gametes in the F1 generation:
- ++ = 35%
- AB = 35%
- +A = 15%
- +B = 15%

**Hint:** Always double-check that the total percentages add up to 100%.

### Final Answer
The types and proportions of gametes in the F1 generation are:
- ++: 35%
- AB: 35%
- +A: 15%
- +B: 15%