General Instructions:
- Copy the given assignment of practical in fair practical copy of biology.
- Make the use of black pen for heading and sub-headings and blue pen for writing other content.
- Work should be presentable.
- Make well labelled and proper diagram as provided in this assignment.
Spot No.4
Aim: To study and identify different stages of gamete development from T.S of mammalian testis through permanent slide.
Materials required: Compound microscope, permanent slides of T.S of mammalian testis.
Theory: In all males organism, gamete formation takes in their gonads i.e testis and ovary. The process of gamete formation is called as gametogenesis which is of following two types.
- Spermatogenesis (formation of male gamete sperms)
- Oogenesis (formation of female gamete ova)
Procedure:
- Clean the slide and microscopes eye and objective lens with the help of cleaning paper.
- Place slide in the stage of microscope. Observe it under low power of microscope followed by high power.
Observation:
- Each testis contains large number of highly coiled seminiferous tubules which appear round in T.S
- Each seminiferous tubule is lined by cubical cells and some modified pyramid shaped cell called as sertoli cell/nurse cells which provide nourishment to the developing sperms.
- The region outside the seminiferous tubules called interstitial space contains a group of interstitial cells which synthesise and secret male androgen i.e testosterone.
- Various developmental stage in sperms are s follows
- Spermatogonia.
- Primary spermatocytes.
- Secondary spermatocytes.
- Spermatids.
- Spermatozoa.
Precautions
- Always handle microscope carefully.
- Observe slide under low power followed by high power.
