Question

1. what step does crossing over occur?

a. prophase i
b. prophase ii
c. metaphase i
d. metaphase ii
e. interphase

1. at which phase do the homologous pairs line up to create a tetrad?

a. prophase ii
b. prophase i
c. metaphase i
d. metaphase ii
e. interphase

1. at which phase do the sister chromatids separate in meiosis?

a. metaphase i
b. metaphase ii
c. telophase i
d. anaphase i
e. anaphase ii

1. what do you call the location of a gene on a chromosome?

a. karyotype
b. centromere
c. locus
d. chromatid

1. how many chromatids make up a tetrad?

a. 1
b. 2
c. 3
d. 4
e. 5

1. during oogenesis what is produced at the end of meiosis ii?

a. 1 viable haploid egg cell
b. 2 viable haploid egg cells
c. 4 viable haploid egg cells
d. 4 viable haploid sperm cells

1. what is the correct sequence of the following events that occur in mitosis?
2. the cytoplasm and organelles are divided between the daughter cells.
3. the nucleolus and nuclear envelope reappear.
4. the centromere splits.
5. the chromosomes condense and the nucleolus disappears.
6. the chromosomes are pulled to the poles of the cell.
7. the chromosomes line up on the equatorial plane.

a. 2, 1, 3, 6, 5, 4
b. 1, 4, 3, 5, 6, 2
c. 4, 3, 6, 5, 1, 2
d. 4, 6, 3, 5, 2, 1
e. 4, 6, 3, 2, 5, 1

Explanation:

Let's solve each question one by one:

Question 9: What step does crossing over occur?

• Explanation: Crossing over occurs during Prophase I of meiosis. In Prophase I, homologous chromosomes pair up (synapsis) and form tetrads, and it is during this time that segments of non - sister chromatids are exchanged.
• Answer: c. Prophase I

Question 10: At which phase do the homologous pairs line up to create a tetrad?

• Explanation: Homologous pairs line up and form tetrads during Prophase I. In Prophase I, the process of synapsis (pairing of homologous chromosomes) takes place, and this leads to the formation of tetrads.
• Answer: b. Prophase I

Question 11: At which phase do the sister chromatids separate in Meiosis?

• Explanation: In Meiosis II, during Anaphase II, the centromeres of the sister chromatids split, and the sister chromatids are pulled apart to opposite poles of the cell. In Meiosis I, it is the homologous chromosomes that separate.
• Answer: d. Anaphase II

Question 12: What do you call the location of a gene on a chromosome?

• Explanation: The specific location of a gene on a chromosome is called a locus (plural: loci). A karyotype is a picture of chromosomes, a centromere is the region where sister chromatids are attached, and a chromatid is one of the two identical parts of a replicated chromosome.
• Answer: c. Locus

Question 13: How many chromatids make up a tetrad?

• Explanation: A tetrad is formed by a pair of homologous chromosomes. Each homologous chromosome consists of two sister chromatids. So, a tetrad has \(2\times2 = 4\) chromatids.
• Answer: d. 4

Question 14: During oogenesis what is produced at the end of Meiosis II?

• Explanation: Oogenesis is the process of egg (ovum) formation. At the end of Meiosis I, a secondary oocyte and a polar body are formed. After Meiosis II (which is completed only if fertilization occurs), one viable haploid egg cell (ovum) and a second polar body are formed. Spermatogenesis produces 4 viable sperm cells, but that's not oogenesis.
• Answer: a. 1 viable haploid egg cell

Question 15: What is the correct sequence of the following events that occur in mitosis?

1. The cytoplasm and organelles are divided between the daughter cells (Cytokinesis)
2. The nucleolus and nuclear envelope reappear (Telophase)
3. The centromere splits (Anaphase)
4. The chromosomes condense and the nucleolus disappears (Prophase)
5. The chromosomes are pulled to the poles of the cell (Anaphase - after centromere splits)
6. The chromosomes line up on the equatorial plane (Metaphase)

• Explanation:
• Step 1: Prophase - The chromosomes condense and the nucleolus disappears (event 4).
• Step 2: Metaphase - The chromosomes line up on the equatorial plane (event 6).
• Step 3: Anaphase - The centromere splits (event 3) and then the chromosomes are pulled to the poles of the cell (event 5).
• Step 4: Telophase - The nucleolus and nuclear envelope reappear (event 2).
• Step 5: Cytokinesis - The cytoplasm and organelles are divided between the daughter cells (event 1).

So the correct order is 4 (Prophase), 6 (Metaphase), 3 (Anaphase - centromere split), 5 (Anaphase - chromosomes pulled), 2 (Telophase), 1 (Cytokinesis) which is 4,6,3,5,2,1.

• Answer: d. 4,6,3,5,2,1

Answer:

Let's solve each question one by one:

Question 9: What step does crossing over occur?

• Explanation: Crossing over occurs during Prophase I of meiosis. In Prophase I, homologous chromosomes pair up (synapsis) and form tetrads, and it is during this time that segments of non - sister chromatids are exchanged.
• Answer: c. Prophase I

Question 10: At which phase do the homologous pairs line up to create a tetrad?

• Explanation: Homologous pairs line up and form tetrads during Prophase I. In Prophase I, the process of synapsis (pairing of homologous chromosomes) takes place, and this leads to the formation of tetrads.
• Answer: b. Prophase I

Question 11: At which phase do the sister chromatids separate in Meiosis?

• Explanation: In Meiosis II, during Anaphase II, the centromeres of the sister chromatids split, and the sister chromatids are pulled apart to opposite poles of the cell. In Meiosis I, it is the homologous chromosomes that separate.
• Answer: d. Anaphase II

Question 12: What do you call the location of a gene on a chromosome?

• Explanation: The specific location of a gene on a chromosome is called a locus (plural: loci). A karyotype is a picture of chromosomes, a centromere is the region where sister chromatids are attached, and a chromatid is one of the two identical parts of a replicated chromosome.
• Answer: c. Locus

Question 13: How many chromatids make up a tetrad?

• Explanation: A tetrad is formed by a pair of homologous chromosomes. Each homologous chromosome consists of two sister chromatids. So, a tetrad has \(2\times2 = 4\) chromatids.
• Answer: d. 4

Question 14: During oogenesis what is produced at the end of Meiosis II?

• Explanation: Oogenesis is the process of egg (ovum) formation. At the end of Meiosis I, a secondary oocyte and a polar body are formed. After Meiosis II (which is completed only if fertilization occurs), one viable haploid egg cell (ovum) and a second polar body are formed. Spermatogenesis produces 4 viable sperm cells, but that's not oogenesis.
• Answer: a. 1 viable haploid egg cell

Question 15: What is the correct sequence of the following events that occur in mitosis?

1. The cytoplasm and organelles are divided between the daughter cells (Cytokinesis)
2. The nucleolus and nuclear envelope reappear (Telophase)
3. The centromere splits (Anaphase)
4. The chromosomes condense and the nucleolus disappears (Prophase)
5. The chromosomes are pulled to the poles of the cell (Anaphase - after centromere splits)
6. The chromosomes line up on the equatorial plane (Metaphase)

• Explanation:
• Step 1: Prophase - The chromosomes condense and the nucleolus disappears (event 4).
• Step 2: Metaphase - The chromosomes line up on the equatorial plane (event 6).
• Step 3: Anaphase - The centromere splits (event 3) and then the chromosomes are pulled to the poles of the cell (event 5).
• Step 4: Telophase - The nucleolus and nuclear envelope reappear (event 2).
• Step 5: Cytokinesis - The cytoplasm and organelles are divided between the daughter cells (event 1).

So the correct order is 4 (Prophase), 6 (Metaphase), 3 (Anaphase - centromere split), 5 (Anaphase - chromosomes pulled), 2 (Telophase), 1 (Cytokinesis) which is 4,6,3,5,2,1.

• Answer: d. 4,6,3,5,2,1