Meiosis Worksheet with Answers (Grade 11 Biology)

This free meiosis worksheet takes Grade 11 students from chromosome basics to what happens when meiosis goes wrong. Students identify six drawn stages of meiosis, colour-coded so they can track the chromosomes from each parent, and compare meiosis with mitosis.

It then covers crossing over and independent assortment, and finishes with nondisjunction: predicting chromosome numbers in gametes and reading karyotypes such as 47,XX,+21. The answer key gives every stage, table entry and calculation.

• Grade 11 Biology
• 30 marks
• 45–60 minutes
• Full answer key

What's in This Meiosis Worksheet

Part	Skill practised	Marks
A	Key terms (diploid, haploid, tetrad, crossing over…)	3
B	Diploid and haploid chromosome numbers	4
C	Identify six stages of meiosis from diagrams	6
D	Mitosis vs meiosis comparison	5
E	Crossing over and independent assortment	4
F	Nondisjunction and karyotypes	6
G	Spot the mistake	2

It supports the Ontario Grade 11 biology curriculum expectations in the Genetic Processes unit. The diagrams use green for chromosomes from the mother and orange for chromosomes from the father.

The Stages of Meiosis

Meiosis turns one diploid cell into four haploid gametes in two divisions. Here are the six stages from Part C in the correct order, for a cell with 2n = 4:

• Prophase I: homologous chromosomes pair up as tetrads and cross over.
• Metaphase I: homologous pairs line up on either side of the equator.
• Anaphase I: homologues separate; sister chromatids stay together.
• Metaphase II: chromosomes line up in single file in each of the two cells.
• Anaphase II: sister chromatids separate.
• Telophase II: four haploid cells form, each genetically different.

The quickest way to tell metaphase I from metaphase II on a meiosis worksheet: in metaphase I chromosomes line up in pairs, in metaphase II they line up singly. For more detail, see Meiosis on Wikipedia.

Mitosis vs Meiosis

Feature	Mitosis	Meiosis
Number of divisions	1	2
Number of daughter cells	2	4
Chromosome number in daughter cells	Diploid (2n), same as the parent	Haploid (n), half of the parent
Genetically identical to parent?	Yes	No, each cell is unique
Purpose	Growth, repair, asexual reproduction	Making gametes (eggs and sperm)

Students fill this table in from memory in Part D of the meiosis worksheet. A human body cell has 46 chromosomes (2n) and a gamete has 23 (n), so fertilization restores 46.

How Meiosis Creates Genetic Variation

Crossing over in prophase I swaps segments between non-sister chromatids, creating new allele combinations. Independent assortment in metaphase I means each homologous pair lines up randomly, giving 2ⁿ possible combinations: 16 for a fruit fly and 8,388,608 for a human, before crossing over is even counted. Random fertilization multiplies the possibilities again.

Nondisjunction and Karyotypes

Nondisjunction happens when chromosomes fail to separate. In meiosis I, a homologous pair goes to the same cell, so all four gametes are abnormal: in humans 24, 24, 22 and 22 chromosomes. In meiosis II, sister chromatids fail to separate in one cell, giving gametes with 24, 22, 23 and 23. When an n + 1 gamete is fertilized by a normal one, the zygote has a trisomy (47 chromosomes).

Karyotype	Disorder	Total chromosomes
47,XX,+21	Down syndrome (trisomy 21)	47
45,X	Turner syndrome (monosomy X)	45
47,XXY	Klinefelter syndrome	47
47,XY,+18	Edwards syndrome (trisomy 18)	47

To see how chromosome behaviour connects to inheritance patterns, try the non-Mendelian genetics quiz.

Meiosis Worksheet Practice Questions

These questions match the meiosis worksheet PDF, which has full-size diagrams and ruled answer space.

Part A – Key Terms

Questions 1–6: match each term to its definition.

1. Diploid (2n)
2. Haploid (n)
3. Homologous chromosomes
4. Sister chromatids
5. Tetrad
6. Crossing over

• a. Exchange of DNA segments between non-sister chromatids of homologous chromosomes
• b. A cell with one set of chromosomes, such as a gamete
• c. Two identical copies of a chromosome joined at a centromere
• d. A cell with two sets of chromosomes, one set from each parent
• e. A homologous pair of duplicated chromosomes (four chromatids) joined in prophase I
• f. A pair of chromosomes carrying the same genes, one from each parent

Part B – Chromosome Numbers

Questions 7–10: fill in the missing numbers.

Organism	Body cell (2n)	Gamete (n)
Human	46	?
Dog	78	?
Fruit fly	?	4
Corn	?	10

Part C – Identify the Stage

Questions 11–16: name the stage of meiosis shown in each cell.

Part D – Mitosis vs Meiosis

Questions 17–21: compare the two processes for each feature in the table above.

Part E – Sources of Variation

22. Describe crossing over: when it happens, which chromosomes are involved, and why it matters. (2 marks)
23. Independent assortment can produce 2ⁿ chromosome combinations, where n is the haploid number. How many combinations are possible for a fruit fly (2n = 8)?
24. How many combinations are possible for a human (2n = 46)? Ignore crossing over.

Part F – Nondisjunction

25. Nondisjunction of chromosome 21 happens in meiosis I of a human cell. How many chromosomes does each of the four gametes have?
26. Nondisjunction instead happens in meiosis II, in one of the two cells only. How many chromosomes does each gamete have?

Questions 27–30: identify the disorder and total chromosome number for 47,XX,+21; 45,X; 47,XXY; and 47,XY,+18.

Part G – Spot the Mistake

31. A student writes: “Meiosis produces two genetically identical diploid cells.” Explain the error and correct it.
32. A student writes: “Crossing over happens between sister chromatids during prophase II.” Explain the error and correct it.

Meiosis Worksheet Answer Key

Open each part of the meiosis worksheet answers to check your work. The printable key is at the end of the PDF.

Part A answers (Q1–6)

1. Diploid (2n): d
2. Haploid (n): b
3. Homologous chromosomes: f
4. Sister chromatids: c
5. Tetrad: e
6. Crossing over: a

Part B answers (Q7–10)

7. Human: 2n = 46, n = 23
8. Dog: 2n = 78, n = 39
9. Fruit fly: 2n = 8, n = 4
10. Corn: 2n = 20, n = 10

Part C answers (Q11–16)

11. Cell A: Anaphase I
12. Cell B: Telophase II (four haploid cells)
13. Cell C: Prophase I (crossing over)
14. Cell D: Metaphase II
15. Cell E: Metaphase I
16. Cell F: Anaphase II

Correct order: C → E → A → D → F → B

Part D answers (Q17–21)

17. Number of divisions: mitosis – 1; meiosis – 2
18. Number of daughter cells: mitosis – 2; meiosis – 4
19. Chromosome number in daughter cells: mitosis – Diploid (2n), same as the parent; meiosis – Haploid (n), half of the parent
20. Genetically identical to parent?: mitosis – Yes; meiosis – No, each cell is unique
21. Purpose: mitosis – Growth, repair, asexual reproduction; meiosis – Making gametes (eggs and sperm)

Part E answers (Q22–24)

22. In prophase I, non-sister chromatids of homologous chromosomes exchange segments. This makes new combinations of alleles on each chromosome, so every gamete is genetically different.
23. n = 4, so 2⁴ = 16 combinations
24. n = 23, so 2²³ = 8,388,608 combinations

Part F answers (Q25–30)

25. Homologues fail to separate: 24, 24, 22, 22 (two gametes n + 1, two gametes n − 1)
26. Sister chromatids fail to separate in one cell: 24, 22, 23, 23 (two gametes are normal)
27. 47,XX,+21: Down syndrome (trisomy 21), 47 chromosomes
28. 45,X: Turner syndrome (monosomy X), 45 chromosomes
29. 47,XXY: Klinefelter syndrome, 47 chromosomes
30. 47,XY,+18: Edwards syndrome (trisomy 18), 47 chromosomes

Part G answers (Q31–32)

31. That describes mitosis. Meiosis produces four genetically different haploid cells.
32. Crossing over happens between non-sister chromatids of homologous chromosomes during prophase I.

5 Common Meiosis Mistakes

1. Mixing up homologues and sister chromatids. Homologues come from different parents; sister chromatids are identical copies.
2. Confusing metaphase I and II. Pairs at the equator means meiosis I; single file means meiosis II.
3. Thinking chromosome number halves in meiosis II. It halves in meiosis I, the reduction division.
4. Placing crossing over in the wrong stage. It only happens in prophase I.
5. Assuming all four gametes are affected by nondisjunction. That is true in meiosis I, but in meiosis II two gametes are normal.

How to Use This Meiosis Worksheet in Class

• Lesson 1: Parts A–D of the meiosis worksheet after teaching the stages. Pipe-cleaner chromosomes make Part C much easier.
• Lesson 2: Parts E–G on variation and nondisjunction.
• Extension: Ask why nondisjunction of the X chromosome is survivable when most autosomal monosomies are not.

Next, apply meiosis to inheritance with the Hardy-Weinberg quiz or review DNA with the protein synthesis quiz.

Frequently Asked Questions

Is this meiosis worksheet free?

Yes. The worksheet and its answer key are free to download and print as a PDF, with no account needed.

What is the difference between meiosis I and meiosis II?

Meiosis I separates homologous chromosomes, halving the chromosome number from diploid to haploid. Meiosis II separates sister chromatids, much like mitosis, so the four final cells are haploid.

Why does meiosis produce genetic variation?

Crossing over in prophase I swaps DNA between homologous chromosomes, and independent assortment in metaphase I shuffles which chromosomes go to each gamete. Random fertilization then combines two unique gametes.

What is nondisjunction?

Nondisjunction is when chromosomes fail to separate during meiosis. The resulting gametes have one chromosome too many or too few, which can lead to conditions such as Down syndrome (trisomy 21) or Turner syndrome (45,X).

What grade is this meiosis worksheet for?

It is written for Grade 11 biology (the Genetic Processes unit) and also works as review for Grade 12 biology.

More Free Grade 11 Biology Resources

• Viruses and Bacteria WorksheetMicroorganisms
• Dichotomous Key WorksheetClassification
• Non-Mendelian Genetics QuizGenetic processes
• Protein Synthesis QuizDNA and RNA
• All Grade 11 ResourcesWorksheets and quizzes

Ready to start? Download the free meiosis worksheet PDF (use the Download button above), print it double-sided, and keep the answer key pages for marking.