Mitosis vs meiosis worksheet | PDF - Free Printable

Let’s go through each question one by one, step by step.

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Question 10: Describe the differences in how the chromosomes line up at middle of the cell during Metaphase I of Meiosis and Metaphase of Mitosis.

In Metaphase of Mitosis, each chromosome (made of two sister chromatids) lines up *individually* along the middle of the cell — like soldiers standing in a single file line. Each chromosome is attached to spindle fibers from both poles.

In Metaphase I of Meiosis, homologous chromosome pairs (each pair = one from mom, one from dad) line up *together* at the middle — like couples holding hands in a line. So instead of individual chromosomes lining up, it’s pairs that line up side-by-side. This is called “tetrads” or “bivalents.”

→ Big difference: In mitosis, chromosomes line up alone. In meiosis I, they line up as matched pairs.

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Question 11: Identify the phase in the cell to the left. What is the name of structure A?

Looking at the cell labeled #11:
- Chromosomes are lined up in the middle → that’s metaphase.
- But wait — there are only 3 chromosomes shown, and they’re not paired. Also, structure A is pointing to the center where chromosomes attach — that’s the centromere.
Wait — actually, looking again: if this is a diploid cell with 6 chromosomes total (as seen in other diagrams), then having 3 chromosomes lined up suggests it’s haploid — which happens in Meiosis II.

Actually, let’s think carefully:

If this is a cell after Meiosis I, it would be haploid. If chromosomes are lined up singly in the middle, that’s Metaphase II of meiosis.

Structure A is pointing to the point where sister chromatids are joined — that’s the centromere.

✔ Phase: Metaphase II
✔ Structure A: Centromere

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Question 12: Identify the phase in the cells to the left. What is happening to the nuclear envelope? Why does this happen?

The three small cells on the left show:
- Chromosomes condensing
- Nuclear envelope breaking apart (you can see fragments or no clear nucleus)
- Spindle forming

This looks like Prophase — but since there are three cells, maybe it’s showing different stages? Actually, all three look similar — likely all in Prophase.

But wait — in meiosis, Prophase I is very long and complex. However, these cells don’t show crossing over or tetrads — so maybe it’s Prophase of Mitosis?

Actually, looking at the context — Question 13 shows telophase-like cells, and this is probably part of mitosis.

So:
✔ Phase: Prophase
✔ Nuclear envelope: It is breaking down / disintegrating
✔ Why? So that spindle fibers can reach the chromosomes and pull them apart later. The nucleus has to disappear so the machinery can access the DNA.

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Question 13: Identify the phase in the cell to the left. What is being separated?

Cell #13 shows:
- Two nuclei forming
- Chromosomes at opposite ends
- Cell starting to pinch in middle (cytokinesis)

That’s Telophase.

What’s being separated? Sister chromatids were already pulled apart in anaphase — now, in telophase, the *chromosomes* are at opposite poles, and the cell is dividing into two daughter cells.

But technically, what was separated earlier (in anaphase) were sister chromatids. In telophase, we’re just finishing up — separating the cytoplasm and reforming nuclei.

So:
✔ Phase: Telophase
✔ What is being separated: Cytoplasm (and organelles) — but the main separation event (of genetic material) happened in anaphase. Since the question says “what is being separated” in this phase, it’s safest to say: the cell is splitting into two daughter cells, so cytoplasm and cellular contents are being divided.

Alternatively, some might say “chromosomes are fully separated at opposite poles” — but they were already moved apart. Let’s stick with:
→ The cell is dividing its cytoplasm and forming two new nuclei.

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Question 14: Explain why meiosis is referred to as a process of cell replication.

Wait — actually, meiosis is NOT typically called “cell replication.” That term usually refers to mitosis, where you make identical copies.

But sometimes people say “replication” loosely meaning “making more cells.” However, strictly speaking:

Mitosis = cell replication (makes 2 identical diploid cells)
Meiosis = cell reduction division (makes 4 unique haploid gametes)

BUT — the question says: “Explain why meiosis is referred to as a process of cell replication.”

Hmm — perhaps it’s a trick? Or maybe they mean that even though it reduces chromosome number, it still involves copying DNA once and dividing twice — so it replicates the cell (into 4 cells).

Actually, let’s read carefully: “cell replication” could mean producing new cells — which meiosis does (gametes). Even though they’re not identical, they are new cells made from the original.

So answer:
Even though meiosis produces genetically different cells with half the chromosomes, it still starts with one cell and ends with four new cells — so it “replicates” the cell in the sense of making multiple offspring cells. Also, DNA is replicated once before meiosis begins (in S phase), so the genetic material is copied first.

✔ Answer: Meiosis is sometimes called cell replication because it begins with one cell and results in four new cells (gametes). Although the daughter cells are not identical and have half the chromosomes, the process still creates new cells — which is a form of replication. Plus, DNA is duplicated once before meiosis starts.

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Question 15: Explain why meiosis is referred to as a process of cell reduction.

This is straightforward.

In meiosis, the chromosome number is cut in half — from diploid (2n) to haploid (n). For example, in humans, body cells have 46 chromosomes; gametes (sperm/egg) have 23.

This “reduction” is essential for sexual reproduction — when sperm and egg combine, they restore the full 46.

✔ Answer: Meiosis is called a process of cell reduction because it reduces the number of chromosomes by half — from diploid (two sets) to haploid (one set). This ensures that when two gametes fuse during fertilization, the resulting zygote has the correct full number of chromosomes.

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Now, compiling final answers clearly:

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Final Answer:

10. In Metaphase of Mitosis, individual chromosomes line up single-file at the equator. In Metaphase I of Meiosis, homologous chromosome pairs (tetrads) line up together at the equator.

11. Phase: Metaphase II
Structure A: Centromere

12. Phase: Prophase
Nuclear envelope: Breaking down/disappearing
Why: To allow spindle fibers to attach to chromosomes and move them during division.

13. Phase: Telophase
What is being separated: Cytoplasm and cellular contents (forming two separate daughter cells); chromosomes are already at opposite poles.

14. Meiosis is called cell replication because it starts with one cell and produces four new cells (gametes). Even though they’re not identical, new cells are created — and DNA is copied once before division begins.

15. Meiosis is called cell reduction because it cuts the chromosome number in half — from diploid (2n) to haploid (n) — so that fertilization restores the full chromosome number.