Meiosis Worksheet : Label The Phases | PDF - Free Printable

Meiosis Worksheet Solution and Explanation

#### 1. A cell with two pairs of each set of chromosomes is called a [ diploid / haploid ] cell. These cells are typically found throughout the body tissues and are called [ germ / somatic ] cells.
- Answer: diploid, somatic
- Explanation: Diploid cells contain two sets of chromosomes (2n), one from each parent. These cells are found in most body tissues and are called somatic cells.

#### 2. A cell with only one set of chromosomes is called a [ diploid / haploid ] cell. These types of cells are found in the reproductive organs and are called [ germ / somatic ] cells.
- Answer: haploid, germ
- Explanation: Haploid cells contain only one set of chromosomes (n). These cells are found in reproductive organs and are called germ cells (sperm or egg cells).

#### 3. Sperm and egg cells are called [ gametes / zygotes ]. A fertilized egg is a [ gamete / zygote ].
- Answer: gametes, zygote
- Explanation: Sperm and egg cells are called gametes because they are involved in sexual reproduction. A fertilized egg is called a zygote, which is the first stage of development after fertilization.

#### 4. A type of cell division that results in diploid cells: [ meiosis / mitosis ]
- Answer: mitosis
- Explanation: Mitosis is the type of cell division that produces diploid cells (2n) by dividing the nucleus into two identical daughter cells.

#### 5. A type of cell division that results in haploid cells: [ meiosis / mitosis ]
- Answer: meiosis
- Explanation: Meiosis is the type of cell division that reduces the chromosome number from diploid (2n) to haploid (n), producing gametes.

#### 6. When a sperm and egg combine, it is called _______.
- Answer: fertilization
- Explanation: Fertilization is the process where a sperm cell fuses with an egg cell, resulting in the formation of a zygote.

#### 7. What is the diploid number for humans? _______ What is the haploid number? _______
- Answer: 46, 23
- Explanation: Humans have 46 chromosomes in their diploid cells (2n = 46). During meiosis, this number is reduced to 23 chromosomes in haploid cells (n = 23).

#### 8. Matching chromosomes are called _______ pairs.
- Answer: homologous
- Explanation: Homologous chromosomes are pairs of chromosomes that are similar in size, shape, and genetic content, one inherited from each parent.

#### 9. During prophase I of meiosis, these pairs form a tetrad in a process called _______.
- Answer: synapsis
- Explanation: Synapsis is the process during prophase I of meiosis where homologous chromosomes pair up and form tetrads.

#### 10. When homologous chromosomes exchange genes, it is called: _______.
- Answer: crossing over
- Explanation: Crossing over is the exchange of genetic material between homologous chromosomes during prophase I of meiosis, which increases genetic diversity.

#### 11. How many daughter cells are created at the end of meiosis I? _______ meiosis II? _______
- Answer: 2, 4
- Explanation: Meiosis I produces 2 daughter cells, each with a haploid number of chromosomes. Meiosis II further divides these cells, resulting in a total of 4 haploid daughter cells.

#### 12. During meiosis, chromosomes will split into daughter cells randomly, making each gamete unique. This is called _______.
- Answer: independent assortment
- Explanation: Independent assortment refers to the random distribution of homologous chromosomes during meiosis I, contributing to genetic variation.

#### 13. The process by which sperm are made is called _______.
- Answer: spermatogenesis
- Explanation: Spermatogenesis is the process of sperm production in males, occurring in the testes.

#### 14. The process by which eggs are made is called _______.
- Answer: oogenesis
- Explanation: Oogenesis is the process of egg production in females, occurring in the ovaries.

#### 15. During the creation of an oocyte, 3 additional haploid cells are created that will not be fertilized; these cells are called _______.
- Answer: polar bodies
- Explanation: During oogenesis, three polar bodies are produced along with the mature egg cell (oocyte). These polar bodies do not participate in fertilization.

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Label the Phases

The images provided represent different stages of meiosis. Here is the labeling:

#### Top Row (Meiosis I):
1. Prophase I: Homologous chromosomes pair up and undergo crossing over.
2. Metaphase I: Homologous chromosome pairs align at the metaphase plate.
3. Anaphase I: Homologous chromosomes separate and move to opposite poles.
4. Telophase I/Cytokinesis: Chromosomes reach opposite poles, and the cell divides into two haploid cells.

#### Bottom Row (Meiosis II):
1. Prophase II: Each haploid cell enters prophase II, and chromosomes condense.
2. Metaphase II: Sister chromatids align at the metaphase plate.
3. Anaphase II: Sister chromatids separate and move to opposite poles.
4. Telophase II/Cytokinesis: Chromatids reach opposite poles, and the cell divides into four haploid cells.

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Final Answer Box:

```plaintext
1. diploid, somatic
2. haploid, germ
3. gametes, zygote
4. mitosis
5. meiosis
6. fertilization
7. 46, 23
8. homologous
9. synapsis
10. crossing over
11. 2, 4
12. independent assortment
13. spermatogenesis
14. oogenesis
15. polar bodies
```

Labeling the Phases:
- Top Row: Prophase I, Metaphase I, Anaphase I, Telophase I/Cytokinesis
- Bottom Row: Prophase II, Metaphase II, Anaphase II, Telophase II/Cytokinesis

Final Answer: \boxed{\text{See explanations above}}
```