Which of the following is not a direct conclusion that can be drawn from Mendel's Experiment ?
a) Only one parental trait is expressed
b) Two copies of each trait is inherited in sexually reproducing organism
c) For recessive trait to be expressed, both copies should be identical
d) Natural selection can alter frequency of an inherited trait.

Options

A. Only one parental trait is expressed
B. Two copies of each trait is inherited in sexually reproducing organism
C. For recessive trait to be expressed, both copies should be identical
D. Natural selection can alter frequency of an inherited trait.

Explanation

To determine which of the options is not a direct conclusion from Mendel's experiments, we can analyze each option based on Mendel's findings.

### Step-by-Step Solution:

1. **Option A: Only one parental trait is expressed.**
- Mendel's Law of Dominance states that in a heterozygous condition, one trait (dominant) will mask the expression of the other trait (recessive). This is a direct conclusion from Mendel's experiments.
- **Conclusion:** This option is correct according to Mendel's findings.

2. **Option B: Two copies of each trait are inherited in sexually reproducing organisms.**
- Mendel's Law of Segregation indicates that organisms inherit two alleles for each trait, one from each parent. This is also a direct conclusion drawn from his experiments.
- **Conclusion:** This option is also correct according to Mendel's findings.

3. **Option C: For a recessive trait to be expressed, both copies should be identical.**
- Mendel observed that a recessive trait is only expressed when both alleles are recessive (homozygous). This is a direct conclusion from his experiments.
- **Conclusion:** This option is correct as well.

4. **Option D: Natural selection can alter the frequency of an inherited trait.**
- This statement relates to the theory of evolution proposed by Charles Darwin, which discusses how natural selection affects traits over generations. It is not a conclusion drawn from Mendel's experiments, which focused on inheritance patterns rather than evolutionary processes.
- **Conclusion:** This option is not a direct conclusion from Mendel's experiments.

### Final Answer:
The option that is not a direct conclusion from Mendel's experiments is **D) Natural selection can alter the frequency of an inherited trait.**

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