Which of the following will not result in variations among siblings ?

Options

A. Independent assortment of genes.
B. Crossing over
C. Linkage .
D. Both (A) and (B)

Answer

To determine which of the following will not result in variations among siblings, we need to analyze the mechanisms of genetic variation. Here’s a step-by-step breakdown of the reasoning:

### Step 1: Understand Genetic Variation
Genetic variation among siblings primarily arises from two processes during meiosis: independent assortment and crossing over.

### Step 2: Independent Assortment
Independent assortment refers to the way chromosomes are distributed into gametes independently of one another. This means that the combination of chromosomes that each gamete receives can vary, leading to different genetic makeups in siblings.

### Step 3: Crossing Over
Crossing over occurs during prophase I of meiosis, where homologous chromosomes exchange segments of their genetic material. This process creates new combinations of alleles on each chromosome, contributing to genetic diversity among siblings.

### Step 4: Mutations
Mutations are changes in the DNA sequence that can also lead to variations. These can occur spontaneously or due to environmental factors and can be inherited if they occur in germ cells.

### Step 5: Genetic Linkage
Genetic linkage refers to genes that are located close to each other on the same chromosome and tend to be inherited together. Because linked genes do not assort independently, they do not contribute to variation among siblings in the same way that independent assortment and crossing over do.

### Conclusion
Based on the above analysis, the correct answer to the question "Which of the following will not result in variations among siblings?" is **linkage**. Linkage does not promote genetic variation because it keeps certain genes together during inheritance.

### Final Answer
**Linkage** is the factor that will not result in variations among siblings.

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