Read the following statements w.r.t. outbreeding devices.
Discourage self pollination.
Prevent loss in genetic variation. Different placement of anther and stigma which prevents autogamy is referred as dichogamy.
Failure of pollen grain`s germinatioin in bisexual or monoecious plants is a genetically controlled mechanism.
select the correct option.

Options

A. a, b & c
B. a, b, c & d
C. b, c & d
D. a, b & d

Answer

To solve the question regarding outbreeding devices, we need to analyze each statement provided and determine if they are correct or not. Here's a step-by-step breakdown:

### Step 1: Analyze Statement 1
**Statement:** "Discourage self-pollination."
**Analysis:** Outbreeding devices are mechanisms that plants have evolved to prevent self-pollination, thus promoting cross-pollination. This statement is correct.

### Step 2: Analyze Statement 2
**Statement:** "Prevent loss in genetic variation."
**Analysis:** By discouraging self-pollination, outbreeding devices help maintain genetic diversity within a population. This statement is also correct.

### Step 3: Analyze Statement 3
**Statement:** "Different placement of anther and stigma which prevents autogamy is referred to as dichogamy."
**Analysis:** The term "dichogamy" refers to the timing of maturation of anthers and stigmas to prevent self-fertilization, not merely their placement. Therefore, this statement is incorrect.

### Step 4: Analyze Statement 4
**Statement:** "Failure of pollen grain's germination in bisexual or monoecious plants is a genetically controlled mechanism."
**Analysis:** This statement is correct. In certain plants, the failure of pollen germination can be a genetically controlled mechanism to prevent self-fertilization.

### Conclusion
Based on the analysis:
- Statement 1: Correct
- Statement 2: Correct
- Statement 3: Incorrect
- Statement 4: Correct

Thus, the correct statements are 1, 2, and 4. The correct option is A, B, and D.

### Final Answer
The correct option is A, B, and D.

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