In human genetics, how many chromosomes are present in a normal human gamete such as a sperm cell or an egg cell?

Introduction / Context:
Human cells come in two basic chromosome number states: diploid and haploid. Diploid cells have two sets of chromosomes, while haploid cells have one set. Gametes are haploid and are critical for sexual reproduction because they combine to restore the diploid state in the zygote. This question asks you to recall the exact number of chromosomes in a normal human gamete.

Given Data / Assumptions:

• We focus on human gametes, specifically sperm or egg cells.
• We assume a genetically normal human without chromosomal abnormalities.
• Options include 23, 46, 92, 102, and 12 chromosomes.
• We assume knowledge that somatic cells in humans are diploid with 46 chromosomes.

Concept / Approach:
Normal human somatic cells contain 46 chromosomes arranged in 23 pairs, which represents the diploid number. During meiosis, diploid germ cells undergo two divisions to produce haploid gametes. Each gamete receives one chromosome from each pair, resulting in 23 chromosomes total. At fertilisation, when a sperm and egg fuse, their chromosome sets combine, restoring the diploid number of 46 in the zygote. Therefore, a normal human gamete contains 23 chromosomes.

Step-by-Step Solution:
Step 1: Recall that human diploid cells have 46 chromosomes, arranged as 23 pairs. Step 2: Understand that gametes are haploid and must contain half the diploid number. Step 3: Calculate half of 46, which equals 23. Step 4: Recognise that meiosis ensures that each gamete gets one chromosome from each pair, yielding 23 chromosomes in total. Step 5: Confirm that at fertilisation, 23 from the sperm plus 23 from the egg creates a zygote with 46 chromosomes. Step 6: Conclude that 23 chromosomes is the correct number for a normal human gamete.

Verification / Alternative check:
Genetics texts consistently state that humans have 2n equals 46 chromosomes, and n equals 23. They explain that human gametes are haploid with n equals 23. Karyotype diagrams show 22 pairs of autosomes and one pair of sex chromosomes in somatic cells. Gametes carry just one chromosome from each pair, which totals 23 chromosomes. This matches the correct option.

Why Other Options Are Wrong:
46 chromosomes: Represents the diploid number in somatic cells, not the haploid number in gametes. 92 chromosomes: Would imply a temporary state after DNA replication but before division, not a normal gamete. 102 chromosomes: Does not match any standard stage of the human cell cycle. 12 chromosomes: Far below human chromosome counts and not a recognised stage.

Common Pitfalls:
Some students memorise 46 as the human chromosome number but forget that gametes contain only half of this. Others confuse the diploid and haploid symbols 2n and n. A simple strategy is to remember that gametes must carry half the genetic information so that fusion restores the full set. Knowing that humans have 46 chromosomes overall leads directly to 23 in each gamete.

Final Answer:
A normal human gamete contains 23 chromosomes.