Advertisements
Advertisements
प्रश्न
What would be the effect if meiosis did not occur in nature?
Advertisements
उत्तर
- During meiosis, reduction division produces four haploid cells (gametes i.e. human sperm cell and egg cell) from a single diploid cell. Hence, if meiosis does not occur, it will result in a doubling of chromosomes in each successive generation, which will result in the formation of abnormalities.
- If meiosis does not occur, the chromosome number of parents and their offsprings will differ in every generation, hence no species will hold its characters.
- Also, there will be no crossing over of homologous chromosomes. Thus, there will be no variations with respect to the changing environment in progeny to maintain their existence, which may lead to the extinction of species.
APPEARS IN
संबंधित प्रश्न
Define the Zygote.
Given below is a portion of the diagram to show the diagrammatic highly magnified view of a single human sperm. Complete the diagram to show its normal structure.
Name the following:
Organ producing sperms.
Name the following:
Organ where fertilization occurs.
Define the following:
Ovulation
The diagram given below is that of a developing human foetus in the womb. Study the same and answer the question that follow:
What term is given to the period of development of the foetus in the womb?
Give Technical Term:
How much semen is discharged per ejaculation in a man?
Give Technical Term:
Rupture of the follicle and release of the ovum from the ovary.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Sperm is a single cell.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
The process of fusion of the sperm nucleus and the egg nucleus is termed implantation.
Write a short note on fallopian tube.
Which of the following occurs due to the process of capacitation?
State whether True or False:
The chromosome number in germ cells producing the gametes are diploid.
What are the functions of each hormone in the neurohypophyseal hormone?
Match the items in column I with those in column II and write down the matching pairs (some may not match).
| Column I | Column II | ||
| (a) | Acrosome | (i) | An embryo which looks like human baby. |
| (b) | Gestation | (ii) | Luteinizing hormone |
| (c) | Menopause | (iii) | Ovum producing cells. |
| (d) | Foetus | (iv) | Semen |
| (e) | Oogenesis | (v) | Spermatozoa |
| (f) | Ovulation | (vi) | Complete stoppage of menstrual cycle. |
| (vii) | Time taken by a fertilised egg till the delivery of baby. |
On which day of the menstrual cycle does ovulation typically occur?
What is the meiotic stage of the ovum at the time of ovulation?
Which substance is located on the surface layer of the egg and acts to attract compatible sperm?
What structures surround the ovum and aid in its protection and fertilization?
