Identification of Stages of Gamete Development

You might be knowing that sex organs are the organs required for sexual reproduction. But where are these organs located? These organs are present in the reproductive system. Gametogenesis is the process through which gamete formation occurs. Spermatogenesis occurs in males to form sperm and oogenesis occurs in females to produce ovum. These organs are not only primary sex organs but also act as endocrine glands that produce a large number of hormones. Such testosterone is secreted by the testis, and oestrogen and progesterone are secreted by the ovary. To know more about ts of testis and ovary, continue reading the article.

Table of Content

• Aim

• Articles Required 

• Theory

• Procedure

• Observations

• Results

• Precautions

• Lab Manual Questions

• Viva Questions

• Practical Based Questions

• Conclusion

Aim

This experiment aims to identify the stages of gamete development, i.e., T.S. of testes and ovaries through permanent slides from mice.

Articles Required

• Permanent slides of T.S of testes

• Permanent slides of T.S of the ovary

• Compound microscope

Theory

Testes are the primary male sex organ whereas ovaries are the primary female sex organ. Both male and female sex organs are paired structures. Ovaries produce female gametes ovum and testes produce male gametes called sperm.

Ovaries are present in the reproductive system and also act as an endocrine gland that produces some important endocrine hormones. Testes are present outside the abdominal cavity in a pouch called the scrotum to maintain a 2-3°C lower temperature. 

Procedure

Place the slides under the microscope. Observe slides both in low as well as high power microscopes.

Observations

T.S of Testis 

• There are two coverings of the testis of mammals. The outer covering is tunica vaginalis and the inner covering is tunica albuginea. 

• Seminiferous tubules are present in testicular lobules. And interstitial tissues are present between seminiferous tubules. 

• Different types of cells are present inside seminiferous tubules. The arrangement of cells inside seminiferous tubules is given below: 

• Spermatogonia, spermatocytes, spermatids, spermatozoa, sperm 

• Between germinal cells Sertoli cells are also present, these cells provide nutrition to germ cells and gametes.

• A large number of spermatozoa with their embedded head in Sertoli cells are present in seminiferous tubules.

• Leydig cells are also present in interstitial space and are responsible for making a hormone called testosterone.

T.S of Testis

T.S of Ovary 

• The ovary of the mouse is covered by a thick layer of germinal epithelium followed by a layer of tunica albuginea. 

• The outer part of the ovary is the cortex and the inner part is the medulla. The inner medulla consists of Graafian follicles which are divided into primary, secondary, or tertiary Graafian follicles at various stages of development. 

• The germinal epithelium of the mammalian ovary is lined by cuboidal epithelium cells.

• The medulla also contains blood vessels, nerves, and smooth muscles. 

• Each follicle contains an ovum which is surrounded by a large number of follicles 

• The cortex contains young and mature follicles 

• The cortex also contains corpus lutetium which is a large yellowish body that acts as an endocrine gland in pregnancy.

T.S of the Ovary

Results

The various parts of the testis and ovum are seen in this experiment.

Precautions

• Slides should be washed properly before using

• All slides should be handled very carefully

• Adjust the lens so that focus would be better. 

Lab Manual Questions

Q1. What is gametogenesis?

Ans: Gametogenesis is defined as the process by which males and females make gametes.

Q2. What are the main parts of spermatozoa?

Ans: Head, neck, middle piece, and tail are the main parts of sperm.

Q3. At what stage does the human ovum release from the ovary?

Ans: At the secondary oocyte stage ovum is released from the ovary.

Viva Questions

Q1. What is oogenesis?

Ans: Oogenesis is the process of the formation of the ovum from germ cells. This process occurs inside the ovum which is a female sex organ.

Q2. What is spermatogenesis?

Ans: Spermatogenesis is the process of the formation of sperm from male germ cells. This process occurs in the testis which is a male sex organ.

Q3. What are the functions of the testis?

Ans: The main function of the testis is to make sperm which is a male gamete and it also acts as an endocrine gland that makes testosterone.

Q4. Explain the functions of the ovary. 

Ans: Ovary is the primary sex organ that makes female gametes ovum. It also acts as an endocrine gland and produces several hormones such as oestrogen and progesterone.

Q5. What are secondary sex organs?

Ans: Secondary sex organs are the organs that facilitate the conduction and transport of gametes and these organs include ducts and glands.

Q6. What is the spermatid?

Ans: Spermatids are haploid cells that are formed by a division in secondary spermatocytes. It further undergoes development to form sperm.

Q7. What is the ploidy of primary spermatocytes?

Ans: Primary spermatocytes are diploid cells that undergo meiosis to form sperm.

Q8. What is the ploidy of spermatids?

Ans: Spermatids are haploid cells formed by meiotic division.

Practical Based Questions

Q1. Which of the following is part of male reproductive system?

1. Testis

2. Breast 

3. Stomach 

4. None of the above 

Ans: 1. Testis

Q2. Which stain is used in ts of the ovary?

1. Safranin 

2. Methylene blue 

3. Iodine 

4. None of the above 

Ans: 1. Safranin

Q3. What is the colour of the ovary?

1. Black 

2. Organ 

3. Grey 

4. Green 

Ans: 4. Grey

Q4. Which of the following is the secondary reproductive organ in male

1. Breast 

2. Testis 

3. Ovary 

4. Epididymis 

Ans: 4. Epididymis 

Q5. What is the normal shape of the testis?

1. Rectangular 

2. Oval

3. Circular 

4. None of the above 

Ans: 2. Oval

Q6. Where is sperm stored?

1. Epididymis 

2. Bulbourethral gland 

3. Prostate gland

4. None of the above 

Ans: 1. Epididymis

Q7. What are the functions of testis?

1. Sperm production 

2. Hormone production 

3. Both of the above 

4. None of the above 

Ans: 3. Both of the above 

Q8. Which hormone is produced by the ovary?

1. Oestrogen 

2. Progesterone 

3. Both of the above 

4. None of the above 

Ans: 3. Both of the above

Conclusion

• In this article, we have studied an experiment on the identification of stages of gamete development.

• We have seen the t.s of mammalian ovaries and t.s of mammalian testis under a microscope.

• Various stages of development have been seen in ts section 

• Spermatogonia, spermatocytes, and spermatids are visible in ts of the testis.

• Different follicular cells of ovaries are also seen in ts of ovaries.