Advertisements
Advertisements
प्रश्न
If newborns are produced at the age of menopause, they may be with some abnormalities. Why?
उत्तर
- A female has millions of oocytes at the time of birth and new ova are not formed thereafter.
- Menopause occurs at approximately 40-50 years of age and hence fewer numbers of eggs are present with reduced fertility since the oocytes have aged.
- Their ability to divide diminishes and they may not be able to complete meiotic division properly.
- Fertilization of such oocytes may result in the production of genetic abnormalities (like Down’s syndrome) in offsprings.
Hence, if newborns are produced at the age of menopause, they may be with some abnormalities.
APPEARS IN
संबंधित प्रश्न
The fusion of the male and the female gametes is called __________.
Fill in the blank.
---------- type of reproduction occurs without fusion of gametes.
Answer the following type of question Assertion (A) and Reason (R).
(A) - Head of the sperm consists of acrosome and mitochondria.
(R) - Acrosome contains spiral rows of mitochondria.
Identify the given image and label its parts marked as a, b, c and d
The following is the illustration of the sequence of ovarian events (a-i) in a human female.
Identify the figure that illustrates ovulation and mention the stage of oogenesis it represents.
Identify the longest period of menstrual cycle.
First meiotic division is observed in ____________.
Conversion of spermatid into sperm is called as _______.
Middle piece of mammalian sperm possesses ______.
Sertoli cells are found in ______.
Connective tissue around seminiferous tubules possess endocrine cells called ______.
At the time of organogenesis, genes regulate the process at different levels and at different time due to ______.
Besides activating the egg another role of a sperm is to carry ______ to egg.
Acrosome is a type of ______.
Which of the following contains the actual genetic part of a sperm?
The prostate gland and seminal vehicle perform the function of ______.
Mark the odd one.
Penetration of the sperm in the ovum is followed by ______
The region of the root tip whose cells undergo rapid elongation and enlargement and are responsible for the growth of the root in length is called the:
The diagram given below shows the various steps in spermatogenesis.
- Name the parts labelled '1', '2' and '3'.
- Name the process by which part '3' changes to part '4'.
