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
State whether the following statement is true (T) or false (F):
A fertilised egg becomes a seed.
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:
Virgin birth
The diagram given below is that of a developing human foetus in the womb. Study the same and answer the question that follow:
Name (any one) hormone produced by the part labelled '2'.
Where does fertilization occur?
Give Reasons
Millions of sperms are produced at ejaculation yet one sperm actually fertilizes the ovum. Explain.
Give Reasons
The oviduct funnel is lined with cilia.
Study the diagram given below and then answer the questions that follow:
(i) Name the part labeled A. Name any two hormones produced by the part labeled A.
(ii) What happens to the part labeled B.
(1) if fertilization takes place?
(2) If fertilization does not take place?
(iii) Where does fertilization occur?
(iv) Draw a neat diagram of the human sperm as seen under high magnification and label the following parts.
(1) Acrosome
(2) Mitochondria
Draw a labeled diagram of sperm.
Give Technical Term:
In how many weeks fetus development is completed?
Give Technical Term:
A method of contraception in which the sperm duct is cut and ligated.
Multiple Choice Question:
Fertilization means:
Which parts are converted into Seed and fruit respectively after fertilization?
How can plants and animals save themselves from extinction?
What is fertilization?
Identify the function of fertilization membrane.
State whether the following statement is True or False. If false, correct the statement:
Human egg has a head, middle piece and tail.
In which part of the human female reproductive system do the following events take place?
Fertilization
What are autosomes chromosomes?
Explain tubectomy and vasectomy.
