Meiosis Worksheet with fill-in-the-blank questions on genetics and cell biology.

Let’s go through each question one by one. I’ll explain the answers clearly so you can understand and fill in your worksheet correctly.

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1. A cell with only one set of chromosomes is called a (diploid / haploid) cell.
→ Haploid cells have just one set of chromosomes — like sperm or egg cells. Diploid cells have two sets (one from each parent).
✔ Answer: haploid

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2. These types are typically found throughout the body tissues and are called (gamete / somatic) cells.
→ Somatic cells = body cells (like skin, muscle, etc.). Gametes = sex cells (sperm/egg).
✔ Answer: somatic

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3. A cell with only one set of chromosomes is called (diploid / haploid) cells.
→ Same as #1 — this is repeating for emphasis. One set = haploid.
✔ Answer: haploid

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4. These types of cells are found in the reproductive organs and are called (gamete / somatic) cells.
→ Reproductive organs make gametes (sperm and eggs).
✔ Answer: gamete

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5. Sperm and egg cells are called (gametes / zygotes).
→ Gametes are the sex cells. Zygote is what forms when sperm + egg join.
✔ Answer: gametes

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6. A type of cell division that results in diploid cells is called (meiosis / mitosis).
→ Mitosis makes identical diploid cells (for growth/repair). Meiosis makes haploid gametes.
✔ Answer: mitosis

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7. A type of cell division that results in haploid cells is called (meiosis / mitosis).
→ Meiosis reduces chromosome number by half → makes haploid cells.
✔ Answer: meiosis

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8. What is the process by which humans reproduce?
→ Humans reproduce sexually — meaning sperm and egg combine.
✔ Answer: sexual reproduction

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9. What is the diploid number for humans? _______ What is the haploid number? _______.
→ Human diploid number = 46 chromosomes (23 pairs). Haploid = 23 (just one set).
✔ Answers: 46, 23

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10. Male gametes are called _______. Female gametes are called _______.
→ Male gamete = sperm. Female gamete = egg (or ovum).
✔ Answers: sperm, egg (or ovum)

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11. During prophase of meiosis, these pair up to form a tetrad. This is called _______.
→ Homologous chromosomes pair up during Prophase I → called “synapsis” or “tetrad formation”. But most worksheets expect: crossing over happens here, but the pairing itself is called synapsis. However, many middle/high school texts say: “homologous chromosomes pair up to form tetrads” — and call it tetrad formation. But the blank likely expects: crossing over? Wait — let’s check context.

Actually, the sentence says: “During prophase of meiosis, these pair up to form a tetrad.” So “these” refers to homologous chromosomes. The process of them pairing is called synapsis, but sometimes simplified to “pairing” or “tetrad formation”.

But looking at common curriculum: Often they say “homologous chromosomes pair up during prophase I to form tetrads” — and the term they want is crossing over? No — crossing over is the exchange of DNA *after* they pair.

Wait — re-read: “these pair up to form a tetrad. This is called _______.”

The act of pairing is synapsis. But if the worksheet is basic, they might accept “tetrad formation” or even “pairing”. But standard answer is synapsis.

However, in many US high school bio classes, they may not use “synapsis” — instead, they might say “homologous chromosomes pair up” and leave it at that. But since there’s a blank, we need a term.

Looking ahead — Question 12 talks about exchanging genes → that’s crossing over.

So for #11: The pairing to form tetrad = synapsis

But let me double-check common textbook language.

Actually, Campbell Biology says: “During prophase I, the duplicated chromosomes condense... homologous chromosomes pair up... forming structures called tetrads.”

They don’t always name the pairing process. But some sources say “synapsis”.

Given that this is a middle/high school worksheet, and question 12 is about gene exchange, I think #11 is expecting: synapsis OR possibly “tetrad formation”.

Wait — another thought: Sometimes they say “the homologous chromosomes pair up in a process called synapsis”.

I’ll go with synapsis — it’s accurate.

But let’s see if there’s a simpler term expected. Maybe “pairing”? Unlikely.

Alternatively, perhaps the blank is for “crossing over” — but no, crossing over is the exchange, not the pairing.

I think safest answer: synapsis

But wait — looking at question 12: “During ____________, chromosomes exchange genes.” That’s definitely crossing over.

So #11 must be the pairing step → synapsis

✔ Answer: synapsis

*(Note: If your class hasn’t learned “synapsis”, ask your teacher — but technically it’s correct.)*

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12. During ____________, chromosomes exchange genes. This increases genetic diversity.
→ This is crossing over — happens in Prophase I of meiosis.
✔ Answer: crossing over

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13. How many daughter cells are created at the end of meiosis? _______ meiosis II?
→ Meiosis I → 2 cells. Meiosis II → each of those splits → total 4 cells.
So: End of meiosis = 4 cells. End of meiosis II = still 4 cells (since meiosis II finishes the process).

Wait — the question says: “How many daughter cells are created at the end of meiosis? _______ meiosis II?”

It might be poorly worded. Probably means:

- At end of meiosis I: 2 cells
- At end of meiosis II: 4 cells

But it says “at the end of meiosis” — which usually means after both divisions → 4 cells.

Then it says “_______ meiosis II?” — maybe it’s asking separately?

Looking at structure: “How many daughter cells are created at the end of meiosis? _______ meiosis II?”

Possibly it’s two blanks: one for end of meiosis, one for end of meiosis II? But that doesn’t make sense because meiosis includes both.

More likely: It’s asking “at the end of meiosis” → 4 cells. And then “meiosis II?” might be a typo or misformatting.

Perhaps it’s: “How many daughter cells are created at the end of meiosis I? _______ meiosis II?”

That would make more sense.

In many worksheets, they ask:

- After meiosis I: 2 cells
- After meiosis II: 4 cells

Given that, and since it says “meiosis II?” at the end, I think it’s implying two parts.

Let me read again: “How many daughter cells are created at the end of meiosis? _______ meiosis II?”

This is ambiguous. But logically:

- End of meiosis (complete process): 4 cells
- End of meiosis II: also 4 cells (since meiosis II completes meiosis)

But that’s redundant.

Alternative interpretation: Perhaps it’s “at the end of meiosis I” and “at the end of meiosis II”

I think that’s what’s intended. Because otherwise, why mention “meiosis II?”

So I’ll assume:

First blank: end of meiosis I → 2 cells
Second blank: end of meiosis II → 4 cells

But the sentence structure is odd.

Looking at the original text: “How many daughter cells are created at the end of meiosis? _______ meiosis II?”

Maybe it’s a fill-in: “at the end of meiosis [I]?” and “meiosis II?”

I think best guess: They want:

- After meiosis I: 2
- After meiosis II: 4

So I’ll put: 2, 4

✔ Answers: 2, 4

*(If your teacher meant something else, clarify — but this is standard.)*

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14. The process by which eggs are made is called _______.
→ Egg production in females = oogenesis
✔ Answer: oogenesis

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15. The process by which sperm are made is called _______.
→ Sperm production = spermatogenesis
✔ Answer: spermatogenesis

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16. In human females, during meiosis, 3 additional haploid cells are created that will not be fertilized; these cells disintegrate. This is called _______.
→ These are polar bodies. The process isn’t named separately — but the cells are called polar bodies. The question says “this is called” — referring to the creation of those extra cells.

Actually, the disintegration of polar bodies is part of oogenesis, but the cells themselves are polar bodies.

The blank likely wants: polar bodies

Because it says “these cells disintegrate. This is called _______.” — “this” refers to the cells, not the process.

Re-reading: “3 additional haploid cells are created... these cells disintegrate. This is called _______.”

“This” probably refers to the cells — so polar bodies

Yes.

✔ Answer: polar bodies

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17. Label the Phases

We have 12 diagrams arranged in 3 rows x 4 columns.

These show stages of meiosis. Let’s identify each.

Recall meiosis has:

Meiosis I:
- Prophase I
- Metaphase I
- Anaphase I
- Telophase I / Cytokinesis

Meiosis II:
- Prophase II
- Metaphase II
- Anaphase II
- Telophase II / Cytokinesis

Now, look at the images:

Top row (left to right):

1. Chromosomes condensed, nuclear envelope breaking down → Prophase I (tetrads visible)
2. Tetrads lined up at equator → Metaphase I
3. Homologous chromosomes pulling apart → Anaphase I
4. Two cells forming, chromosomes at poles → Telophase I / Cytokinesis

Middle row:

5. Two cells, chromosomes condensing again → Prophase II
6. Chromosomes lined up single file at equator → Metaphase II
7. Sister chromatids separating → Anaphase II
8. Four cells starting to form → Telophase II / Cytokinesis

Bottom row:

9. Four separate cells, each with single chromosomes → Gametes (final product) — but technically, after telophase II, cytokinesis completes → so this is end result.

Wait — actually, bottom row shows four cells, each with unreplicated chromosomes → these are the final gametes.

But the labeling should be phases.

Looking carefully:

Image 9: Four distinct cells → Cytokinesis complete or Gametes

But in sequence, after telophase II comes cytokinesis.

Typically, the last phase is Telophase II followed by cytokinesis.

In many diagrams, the fourth image in second row is telophase II, and bottom row shows the resulting cells.

But let’s map:

Standard order:

Row 1: Meiosis I phases
- Image 1: Prophase I
- Image 2: Metaphase I
- Image 3: Anaphase I
- Image 4: Telophase I

Row 2: Meiosis II phases
- Image 5: Prophase II
- Image 6: Metaphase II
- Image 7: Anaphase II
- Image 8: Telophase II

Row 3: Final products — but often labeled as "Gametes" or "Daughter Cells"

But the instruction is “Label the Phases”, so probably all 12 are to be labeled with phase names.

Image 9,10,11,12 — all show four separate cells, each with single chromosomes. These are the end result — so perhaps “Gametes” or “Haploid Cells”

But technically, after telophase II and cytokinesis, you have four haploid cells.

In some curricula, they consider the last stage as “Telophase II/Cytokinesis” and then the cells are shown separately.

To match standard labeling:

Let’s assign:

Top row:
1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I

Middle row:
5. Prophase II
6. Metaphase II
7. Anaphase II
8. Telophase II

Bottom row:
9. Cytokinesis (or Gamete Formation)
10. Gametes
11. Gametes
12. Gametes

But that’s inconsistent.

Notice that images 9-12 are identical — all show four separate cells. So likely, they represent the final outcome.

Perhaps the diagram is showing the entire process, and bottom row is just illustrating the result.

But since it says “label the phases”, and there are 12 boxes, probably each box corresponds to a stage.

Another way: In some diagrams, after telophase II, they show cytokinesis producing four cells, and then the cells are depicted.

I think for simplicity, and based on common worksheets:

Label as follows:

Top row (Meiosis I):
1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I

Middle row (Meiosis II):
5. Prophase II
6. Metaphase II
7. Anaphase II
8. Telophase II

Bottom row:
9. Cytokinesis (completion)
10. Gametes
11. Gametes
12. Gametes

But that’s not precise.

Perhaps images 9-12 are all “Gametes” or “Haploid Daughter Cells”

Since the question is to label phases, and gametes aren't a phase, maybe the bottom row is not phases but the result.

Looking back at the image description — it's a grid of 12 circles, each with a cell diagram.

Upon closer inspection (from typical such worksheets), the bottom row often shows the four resulting gametes, so they might be labeled as "Gametes" or left as is.

But to be accurate, let's think:

After Telophase II, cytokinesis occurs, resulting in four haploid cells. So image 8 might be telophase II, and images 9-12 show the separated cells.

In many resources, the last phase is Telophase II, and then the cells are shown without a specific phase name.

For this exercise, I'll label:

Top row:
1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I

Middle row:
5. Prophase II
6. Metaphase II
7. Anaphase II
8. Telophase II

Bottom row:
9. Gamete
10. Gamete
11. Gamete
12. Gamete

Or perhaps "Daughter Cell" for each.

Since they are identical, and the process is complete, "Gamete" is fine.

Some might say "Haploid Cell".

But "Gamete" is appropriate since it's for reproduction.

✔ So for labeling:

Write under each image:

Top row:
1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I

Middle row:
5. Prophase II
6. Metaphase II
7. Anaphase II
8. Telophase II

Bottom row:
9. Gamete
10. Gamete
11. Gamete
12. Gamete

*(Note: Some teachers might prefer "Cytokinesis" for the separation, but since the cells are already formed, "Gamete" is acceptable.)*

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Now, compiling all answers for the worksheet:

1. haploid
2. somatic
3. haploid
4. gamete
5. gametes
6. mitosis
7. meiosis
8. sexual reproduction
9. 46, 23
10. sperm, egg (or ovum)
11. synapsis
12. crossing over
13. 2, 4 (assuming end of meiosis I and end of meiosis II)
14. oogenesis
15. spermatogenesis
16. polar bodies
17. As above:
Top row: Prophase I, Metaphase I, Anaphase I, Telophase I
Middle row: Prophase II, Metaphase II, Anaphase II, Telophase II
Bottom row: Gamete, Gamete, Gamete, Gamete

Final Answer:
Here are the completed answers for your worksheet:

1. haploid
2. somatic
3. haploid
4. gamete
5. gametes
6. mitosis
7. meiosis
8. sexual reproduction
9. 46, 23
10. sperm, egg
11. synapsis
12. crossing over
13. 2, 4
14. oogenesis
15. spermatogenesis
16. polar bodies
17. Label the phases as follows:
- Top row (left to right): Prophase I, Metaphase I, Anaphase I, Telophase I
- Middle row (left to right): Prophase II, Metaphase II, Anaphase II, Telophase II
- Bottom row (left to right): Gamete, Gamete, Gamete, Gamete