Question

question 19 of 25

how does fertilization produce cells with genetic variation?

a. through a reduction in the total number of chromosomes
b. through independent assortment and crossing over
c. through the combination of gametes from two different parents
d. through the process of chromosome replication

Explanation:

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<reasoning>

Define fertilization and its role

Using the Sexual Reproduction knowledge point, fertilization is the process where two haploid gametes (sperm and egg) fuse to form a single diploid zygote. This process combines genetic material from two distinct individuals.

Analyze sources of genetic variation

Using the Genetic Variation knowledge point, we evaluate how different processes contribute to diversity:

• Independent assortment and crossing over occur during meiosis (gamete formation), not during fertilization itself.
• Chromosome replication copies DNA but does not generate new genetic combinations.
• Fertilization creates variation by randomly combining unique gametes from two different parents, resulting in a genetically unique offspring.

Evaluate the given options

• A is incorrect because fertilization restores the diploid number rather than reducing chromosomes.
• B is incorrect because independent assortment and crossing over are meiotic processes.
• C is correct because combining gametes from two parents creates a unique genetic combination.
• D is incorrect because replication simply duplicates existing DNA.

</reasoning>

<answer>
<mcq-option>A. Through a reduction in the total number of chromosomes</mcq-option>
<mcq-option>B. Through independent assortment and crossing over</mcq-option>
<mcq-correct>C. Through the combination of gametes from two different parents</mcq-correct>
<mcq-option>D. Through the process of chromosome replication</mcq-option>
</answer>

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Answer:

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<reasoning>

Define fertilization and its role

Using the Sexual Reproduction knowledge point, fertilization is the process where two haploid gametes (sperm and egg) fuse to form a single diploid zygote. This process combines genetic material from two distinct individuals.

Analyze sources of genetic variation

Using the Genetic Variation knowledge point, we evaluate how different processes contribute to diversity:

• Independent assortment and crossing over occur during meiosis (gamete formation), not during fertilization itself.
• Chromosome replication copies DNA but does not generate new genetic combinations.
• Fertilization creates variation by randomly combining unique gametes from two different parents, resulting in a genetically unique offspring.

Evaluate the given options

• A is incorrect because fertilization restores the diploid number rather than reducing chromosomes.
• B is incorrect because independent assortment and crossing over are meiotic processes.
• C is correct because combining gametes from two parents creates a unique genetic combination.
• D is incorrect because replication simply duplicates existing DNA.

</reasoning>

<answer>
<mcq-option>A. Through a reduction in the total number of chromosomes</mcq-option>
<mcq-option>B. Through independent assortment and crossing over</mcq-option>
<mcq-correct>C. Through the combination of gametes from two different parents</mcq-correct>
<mcq-option>D. Through the process of chromosome replication</mcq-option>
</answer>

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"knowledge_point": [
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"Sexual Reproduction and Genetics"
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