Which of the Following Statements About Meiosis Is True?

Meiosis is a specialized type of cell division that produces gametes — sperm and egg cells — each with half the normal chromosome number. If you’re asking which of the following statements about meiosis is true, the direct answer is this: meiosis produces four genetically unique haploid cells from one starting diploid cell, and it involves two rounds of division (meiosis I and meiosis II) after only one round of DNA replication.

That single sentence captures the most commonly tested idea. Most wrong answers on quizzes confuse meiosis with mitosis, mix up the chromosome numbers, or assume the daughter cells are identical. Let’s break down the details so the correct statement stands out clearly.

Two Divisions, One Replication

The defining feature of meiosis is that it uses two nuclear divisions to halve the chromosome number. Before meiosis begins, the cell replicates its DNA once during the S phase of interphase. Then it divides twice in a row, without another round of replication in between. The National Human Genome Research Institute describes meiosis as the process that reduces a diploid cell to haploid cells, which is exactly what gametes need.

Meiosis I vs. Meiosis II

• Meiosis I is the reductional division. Homologous chromosomes pair up and separate, so each resulting cell gets one chromosome from each pair. The chromosome number drops from diploid (2n) to haploid (n).
• Meiosis II is the equational division. It looks much like mitosis: sister chromatids separate. Because there’s no new DNA replication, each of the four final cells ends with half the original chromosome number.

This single-replication, double-division pattern is why one diploid cell yields four haploid cells rather than two. In humans, that means a starting cell with 46 chromosomes gives rise to gametes with 23 chromosomes each.

Genetic Variation Is the Whole Point

A statement that ignores genetic diversity is usually the false one. Meiosis has two built-in mechanisms for shuffling genes, and this is the core reason sexual reproduction generates variation.

During prophase I, homologous chromosomes pair tightly and exchange segments at points called chiasmata. This process, called crossing over (or recombination), swaps DNA between maternal and paternal chromosomes. The result is chromosomes that carry a mix of both parents’ alleles — combinations that existed in neither parent.

The way homologues line up at the metaphase I plate is also random. Each pair orients independently of the others, so the maternal and paternal chromosomes are distributed into gametes in many possible combinations. The NCBI Bookshelf covers how this assortment, combined with crossing over, produces enormous genetic variety.

A quick example makes it concrete: humans have 23 chromosome pairs, so independent assortment alone can produce over 8 million different combinations of chromosomes in gametes. Crossing over multiplies that number far higher. Two siblings from the same parents are therefore almost never genetically identical.

How Meiosis Differs From Mitosis

Many quiz questions hinge on contrasting these two processes. The table below separates them cleanly.

The single most reliable shortcut: if a statement says meiosis makes identical cells or keeps the chromosome number the same, it’s false. If it says meiosis makes four unique haploid cells, it’s true.

Common True-or-False Traps

Test writers reuse a small set of misleading statements. Knowing the traps helps you spot the correct option fast.

• “Meiosis occurs in all body cells.” False. It happens only in germ cells of reproductive tissue. Khan Academy notes that body (somatic) cells divide by mitosis.
• “Meiosis produces two daughter cells.” False — that’s mitosis. Meiosis produces four.
• “The daughter cells are identical to the parent.” False. Crossing over and independent assortment guarantee they aren’t, even before fertilization.
• “Sister chromatids separate in meiosis I.” False. Homologues separate in meiosis I; sister chromatids separate in meiosis II.
• “Meiosis halves the chromosome number.” True. This is the reductional outcome of meiosis I.

One more distinction worth remembering: homologous chromosomes are similar but not identical — one came from each parent and they carry the same genes in the same order. Sister chromatids are exact copies of a single chromosome, joined at the centromere until they separate. Mixing these two up is behind many incorrect answers.

Meiosis in Human Reproduction

The haploid gametes that meiosis produces meet at fertilization to restore the diploid number. A sperm with 23 chromosomes and an egg with 23 chromosomes combine to form a zygote with 46 — 23 pairs. Half of those pairs come from each parent, which is why traits can skip generations or reappear in later offspring.

Errors in meiosis — such as a pair of homologues or sister chromatids failing to separate, called nondisjunction — produce gametes with an abnormal chromosome number. Fertilization involving such a gamete leads to aneuploidy, a condition in which the embryo has an extra or missing chromosome.

Key Takeaways

• The true statement: meiosis produces four genetically unique haploid cells from one diploid cell through two divisions after a single DNA replication.
• Meiosis I separates homologous chromosomes and halves the chromosome number; meiosis II separates sister chromatids.
• Crossing over and independent assortment generate genetic variation — the daughter cells are never identical.
• Meiosis makes gametes; mitosis makes identical cells for growth and repair.
• In humans, meiosis takes a 46-chromosome cell down to gametes with 23 chromosomes.
• Watch for traps: statements claiming identical cells, two daughter cells, or an unchanged chromosome number are false.