How many chromosomes are normally present in the first cell formed after fertilisation in humans?
Answer and explanation
Correct answer: Forty-six
Human gametes are haploid: the egg contributes 23 chromosomes and the sperm contributes another 23. Fertilisation combines these two sets in the zygote, the first cell formed after fertilisation. Therefore, 23 + 23 = 46 chromosomes, arranged in 23 pairs. Option B is correct. Twenty-three is the number in one gamete, while 92 and 11 do not represent the normal human zygote number.
Frequently asked questions
What is the correct answer to this question?
Forty-six
Why is this the correct answer?
Human gametes are haploid: the egg contributes 23 chromosomes and the sperm contributes another 23. Fertilisation combines these two sets in the zygote, the first cell formed after fertilisation. Therefore, 23 + 23 = 46 chromosomes, arranged in 23 pairs. Option B is correct. Twenty-three is the number in one gamete, while 92 and 11 do not represent the normal human zygote number.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Light Reflection and Refraction. Topic: Image formation.
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