Adv.biom16l1 Part 2

1. In Meiosis I, describe Early Prophase I.

The chromosomes and centriole duplicate and the centrioles begin to move.

The nuclear envelope breaks down and the spindle fibers start to form.

The sister chromatids separate and move towards opposite poles of the cell.

Early Prophase I in Meiosis I is characterized by the condensation of chromosomes, pairing up of homologous chromosomes, and crossing over to exchange genetic material. This stage sets the foundation for genetic diversity in the resulting gametes.

Explanation

Early Prophase I in Meiosis I is characterized by the condensation of chromosomes, pairing up of homologous chromosomes, and crossing over to exchange genetic material. This stage sets the foundation for genetic diversity in the resulting gametes.

2. In Meiosis I, describe Late Prophase I.

The chromosomes start to separate into chromatids.

The nuclear membrane disintegrates.

The chromosomes line up in homologous pairs and the spindle begins to form.

The centrioles move to opposite poles of the cell.

In Late Prophase I of Meiosis I, chromosomes pair up in homologous pairs, a critical step for genetic recombination to occur. While the nuclear membrane disintegrates and the centrioles move during other phases, they do not specifically occur during Late Prophase I.

Explanation

In Late Prophase I of Meiosis I, chromosomes pair up in homologous pairs, a critical step for genetic recombination to occur. While the nuclear membrane disintegrates and the centrioles move during other phases, they do not specifically occur during Late Prophase I.

3. In Meiosis I, describe Metaphase I.

The nuclear membrane starts to break down.

The chromosomes line up on the equatorial plane. The microtubules attach to one homologue each.

The centromeres divide and the sister chromatids separate.

The chromosomes pair up in preparation for crossing over.

4. In Meiosis I, describe Anaphase I.

The genetic material condenses into chromosomes, and the nuclear membrane disappears.

The microtubules of the spindle pull the homologues apart.

The cytoplasm divides to form two daughter cells, each with half the number of chromosomes as the original cell.

The centromeres of the sister chromatids divide and the chromatids move to opposite poles.

Anaphase I in Meiosis I is specifically characterized by the separation of homologous chromosomes, not sister chromatids like in Anaphase II. This process is essential for ensuring genetic diversity in the resulting daughter cells.

Explanation

Anaphase I in Meiosis I is specifically characterized by the separation of homologous chromosomes, not sister chromatids like in Anaphase II. This process is essential for ensuring genetic diversity in the resulting daughter cells.

5. In Meiosis I, describe Telophase I.

The nuclear envelope breaks down, and spindle fibers attach to the chromosomes.

Crossing over between homologous chromosomes occurs.

The chromosomes replicate to form sister chromatids.

The plasma membrane constricts, and the chromosomes become surrounded by nuclear material.

Telophase I is the final stage of Meiosis I where the chromosomes have reached the poles of the cell, and the plasma membrane constricts to separate the two sets of chromosomes. The chromosomes are surrounded by nuclear material to form two separate nuclei.

Explanation

Telophase I is the final stage of Meiosis I where the chromosomes have reached the poles of the cell, and the plasma membrane constricts to separate the two sets of chromosomes. The chromosomes are surrounded by nuclear material to form two separate nuclei.

6. In Meiosis I, describe End of Meiosis I?

Two haploid cells result. They still have duplicated chromosomes, however, so they must enter meiosis II.

One diploid cell results, which undergoes further cell division in meiosis II.

No cells are formed at the end of meiosis I; it is a preparatory phase for meiosis II.

Four diploid cells result, ready for fertilization in meiosis II.

At the end of Meiosis I, two haploid cells are formed, but they still have duplicated chromosomes and need to undergo further division in Meiosis II to become fully haploid cells for reproductive purposes.

Explanation

At the end of Meiosis I, two haploid cells are formed, but they still have duplicated chromosomes and need to undergo further division in Meiosis II to become fully haploid cells for reproductive purposes.

7. In Meiosis II, describe Prophase II.

Both cells form spindle fibers.

Both cells duplicate centrioles.

Both cells divide into haploid cells.

Both cells undergo DNA replication.

Prophase II in Meiosis II is characterized by the duplication of centrioles in the two daughter cells.

Explanation

Prophase II in Meiosis II is characterized by the duplication of centrioles in the two daughter cells.

8. In Meiosis II, describe Metaphase II.

The chromosomes replicate to form sister chromatids.

The homologous chromosomes pair up and exchange genetic material.

The nuclear membrane disintegrates.

The chromosomes of each cell line up on the equatorial plane.

In Metaphase II of Meiosis II, the chromosomes line up at the equatorial plane of each cell. This is crucial for proper division of genetic material.

Explanation

In Metaphase II of Meiosis II, the chromosomes line up at the equatorial plane of each cell. This is crucial for proper division of genetic material.

9. In Meiosis II, describe Anaphase II?

The nuclear membrane breaks down.

The microtubules pull the duplicates from the originals.

The chromosomes condense and become visible.

The cell divides into two daughter cells.

Anaphase II in Meiosis II involves the separation of sister chromatids towards opposite poles of the cell due to the pulling action of microtubules.

Explanation

Anaphase II in Meiosis II involves the separation of sister chromatids towards opposite poles of the cell due to the pulling action of microtubules.

10. In Meiosis II, describe Telophase II.

The nuclear envelope disappears and spindle fibers attach to the chromosomes.

The plasma membranes constrict, and nuclei form.

The sister chromatids are pulled apart towards opposite poles of the cell.

The chromosomes line up in the center of the cell.

Telophase II is the final stage of Meiosis II where the plasma membranes constrict, and nuclei form, leading to the formation of four haploid daughter cells.

Explanation

Telophase II is the final stage of Meiosis II where the plasma membranes constrict, and nuclei form, leading to the formation of four haploid daughter cells.

11. How many homologous pairs of chromosomes are in a normal human cell?

25

24

22

23.........This means there are a total of 46 chromosomes.

Human cells have a total of 46 chromosomes, which are arranged into 23 homologous pairs. Each pair consists of one chromosome inherited from the mother and one from the father, making a total of 23 pairs.

Explanation

Human cells have a total of 46 chromosomes, which are arranged into 23 homologous pairs. Each pair consists of one chromosome inherited from the mother and one from the father, making a total of 23 pairs.

12. What is the haploid number of a cell?

The total number of genes present in a cell

The total number of chromosomes present in a cell

The number of non-homologous pairs of chromosomes in a cell

The number of homologous pairs is called the haploid number of the cell, thus the haploid number of human cells is 23

The haploid number refers to the number of homologous pairs of chromosomes in a cell. In humans, this number is 23, representing one set of chromosomes.

Explanation

The haploid number refers to the number of homologous pairs of chromosomes in a cell. In humans, this number is 23, representing one set of chromosomes.

13. The total number of chromosomes in the cell is called the _______

Genetic code

Chromosomal count

Haploid number

Diploid number the diploid number of human cells is 46

The diploid number refers to the total number of chromosomes in a cell, with humans having a diploid number of 46. The other options do not specifically refer to the total number of chromosomes in a cell.

Explanation

The diploid number refers to the total number of chromosomes in a cell, with humans having a diploid number of 46. The other options do not specifically refer to the total number of chromosomes in a cell.

14. What type of cells do meiosis produce?

Triploid cells

Diploid cells

Tetraploid cells

Meiosis produces cells which have only one chromosome from each homologous pair. Thus, it produces cells with only the haploid number. These are called haploid cells

Meiosis is a type of cell division that results in the formation of haploid cells, each containing one set of chromosomes. This is in contrast to mitosis, which produces diploid cells with two sets of chromosomes. Therefore, diploid, tetraploid, and triploid cells are incorrect in the context of cells produced by meiosis.

Explanation

Meiosis is a type of cell division that results in the formation of haploid cells, each containing one set of chromosomes. This is in contrast to mitosis, which produces diploid cells with two sets of chromosomes. Therefore, diploid, tetraploid, and triploid cells are incorrect in the context of cells produced by meiosis.

15. Haploid cells. Since the cells are used for reproduction, they are also called___________.

Since the cells are used for reproduction, they are also called gametes

Stem cells

Somatic cells

Zygotes

Haploid cells, specifically gametes, are cells used for reproduction to form a zygote. Somatic cells are non-reproductive cells, and stem cells have the potential to differentiate into various cell types but are not specific to reproduction like gametes.

Explanation

Haploid cells, specifically gametes, are cells used for reproduction to form a zygote. Somatic cells are non-reproductive cells, and stem cells have the potential to differentiate into various cell types but are not specific to reproduction like gametes.

16. Where does spermatogenesis occur in the testes?

Epididymis

Vas deferens

Spermatogenesis occurs in the seminiferous tubules of the testes

Interstitial cells

Spermatogenesis, the process of sperm production, specifically occurs within the seminiferous tubules of the testes. The incorrect answers are structures within the male reproductive system but not the specific site of sperm production.

Explanation

Spermatogenesis, the process of sperm production, specifically occurs within the seminiferous tubules of the testes. The incorrect answers are structures within the male reproductive system but not the specific site of sperm production.

17. Where does spermatogenesis occur?

Spermatogenesis occurs in the prostate gland.

Spermatogenesis occurs in the epididymis.

Spermatogenesis occurs in the vas deferens.

Spermatogenesis occurs in the seminiferous tubules of the testes. The process begins with cells called spermatogonia.

Spermatogenesis is the process of sperm cell development and maturation, which takes place in the seminiferous tubules of the testes where germ cells called spermatogonia differentiate and undergo a series of cell divisions.

Explanation

Spermatogenesis is the process of sperm cell development and maturation, which takes place in the seminiferous tubules of the testes where germ cells called spermatogonia differentiate and undergo a series of cell divisions.

18. When spermatogonia undergo mitosis, what two types of cells result?

The two types of cells resulting from mitosis are primary spermatocytes and spermatid stem cells.

The two types of cells resulting from mitosis are spermatids and Leydig cells.

One of the two cells that results from mitosis remains a spermatogonium (singular of spermatogonia), and the other is a primary spermatocyte which is the cell that actually undergoes meiosis.

The two types of cells resulting from mitosis are secondary spermatocytes and spermatozoa.

During the process of spermatogenesis, spermatogonia divide by mitosis to produce two types of cells, one of which is the primary spermatocyte. This primary spermatocyte then undergoes meiosis to eventually form sperm cells. The incorrect answers provided do not accurately reflect the division of spermatogonia cells during mitosis.

Explanation

During the process of spermatogenesis, spermatogonia divide by mitosis to produce two types of cells, one of which is the primary spermatocyte. This primary spermatocyte then undergoes meiosis to eventually form sperm cells. The incorrect answers provided do not accurately reflect the division of spermatogonia cells during mitosis.

19. What is the primary spermatocyte?

The final mature sperm cell

A type of white blood cell present in the testes

The cell that actually undergoes meiosis. Each primary spermatocyte, which has 46 duplicated chromosomes, undergoes meiosis I to make two secondary spermatocytes

A cell involved in the production of testosterone

The primary spermatocyte is the cell that undergoes meiosis to form two secondary spermatocytes, which then undergo further division to eventually produce sperm cells. It is not the final mature sperm cell, nor is it involved in testosterone production or part of the immune system in the testes.

Explanation

The primary spermatocyte is the cell that undergoes meiosis to form two secondary spermatocytes, which then undergo further division to eventually produce sperm cells. It is not the final mature sperm cell, nor is it involved in testosterone production or part of the immune system in the testes.

20. What is the characteristic of secondary spermatocytes during meiosis?

Secondary spermatocytes have 23 chromosomes each with no duplication.

These cells have 46 chromosomes each, with one from each homologous pair.

Secondary spermatocytes have an uneven number of chromosomes compared to primary spermatocytes.

These cells have only one chromosome from each homologous pair, but those chromosomes are duplicated. Thus, they have 23 duplicated chromosomes. They therefore undergo meiosis II to separate the duplicates.

Secondary spermatocytes are haploid cells that have undergone meiosis I, resulting in two cells with 23 duplicated chromosomes each. These cells then undergo meiosis II to separate the duplicated chromosomes and form spermatids.

Explanation

Secondary spermatocytes are haploid cells that have undergone meiosis I, resulting in two cells with 23 duplicated chromosomes each. These cells then undergo meiosis II to separate the duplicated chromosomes and form spermatids.

21. What are spermatids?

Sperms produced after meiosis I

Primary spermatocytes with duplicated chromosomes

Ova produced during spermatogenesis

After meiosis II where the duplicates are separated, a total of four spermatids are left, each with only 23 chromosomes, none of which are duplicated. The spermatids, then, have only one allele for every gene.
Once formed, the spermatids develop specific features

Spermatids are the final product of spermatogenesis, they are formed after both meiosis I and meiosis II, have only 23 chromosomes and undergo further development to mature into sperm cells with specialized features.

Explanation

Spermatids are the final product of spermatogenesis, they are formed after both meiosis I and meiosis II, have only 23 chromosomes and undergo further development to mature into sperm cells with specialized features.

22. What happens to the spermatids when they are fully developed?

When the spermatids are fully developed, they fuse with the egg cells immediately.

When the features are developed, the sperm enter the lumen of the seminiferous tubules so that they can go to the epididymides to become fully mature.

When the spermatids are fully developed, they remain in the seminiferous tubules indefinitely.

When the spermatids are fully developed, they are released into the bloodstream.

Spermatids need to go through further maturation in the epididymides before becoming fully mature sperm cells capable of fertilization.

Explanation

Spermatids need to go through further maturation in the epididymides before becoming fully mature sperm cells capable of fertilization.

23. How long does the process of spermatogenesis take?

The process of spermatogenesis takes about 120 days.

The process of spermatogenesis takes about 10 days.

The process of spermatogenesis takes about 30 days.

The entire process of spermatogenesis takes about 70 days.

Spermatogenesis is the process of sperm production in males, which involves multiple stages such as proliferation, meiosis, and spermiogenesis. The correct answer of approximately 70 days accounts for the full duration from spermatogonia to mature spermatozoa.

Explanation

Spermatogenesis is the process of sperm production in males, which involves multiple stages such as proliferation, meiosis, and spermiogenesis. The correct answer of approximately 70 days accounts for the full duration from spermatogonia to mature spermatozoa.

24. How long can a fully mature sperm live inside a male and inside a female?

A fully mature sperm can only live for a few hours inside a male and a few months inside a female.

Once fully mature, a sperm can live for several weeks inside the male. Once in the vagina, however, it can live for only a few days

A fully mature sperm can live indefinitely inside both male and female bodies.

A fully mature sperm can live for a few days inside a male and several weeks inside a female.

Sperm can live longer inside the male due to controlled temperature and protection, while inside the female reproductive tract, it has a shorter lifespan due to the acidic environment and the presence of immune cells.

Explanation

Sperm can live longer inside the male due to controlled temperature and protection, while inside the female reproductive tract, it has a shorter lifespan due to the acidic environment and the presence of immune cells.

25. What are the three basic sections of sperm?

Sperm can be divided into three basic sections: the nucleus, the cytoplasm, and the flagellum.

Sperm can be divided into three basic sections: the acrosome, the centriole, and the axoneme.

Sperm can be divided into three basic sections: the base, the neck, and the mitochondria.

Sperm can be divided into three basic sections: the head, the midpiece, and the tail.

The correct answer is that sperm can be divided into three basic sections: the head, the midpiece, and the tail.

Explanation

The correct answer is that sperm can be divided into three basic sections: the head, the midpiece, and the tail.

26. The rest of the head houses the nucleus, which contains how many chromosomes, one from each homologous pair?

23

46

12

32

In humans, each cell contains a total of 46 chromosomes, with 23 pairs. When it comes to homologous pairs, there are 23 unique chromosomes, one from each pair.

Explanation

In humans, each cell contains a total of 46 chromosomes, with 23 pairs. When it comes to homologous pairs, there are 23 unique chromosomes, one from each pair.