Advertisements
Advertisements
Question
What would be the effect if meiosis did not occur in nature?
Advertisements
Solution
- 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
RELATED QUESTIONS
State whether the following statement is true (T) or false (F):
A fertilised egg becomes a seed.
State whether the following statement is true (T) or false (F):
The plumule of an embryo gives rise to the root system.
Rewrite the terms in the correct order so as to be in a logical sequence.
coitus, ovum, Sperm, sperm duct, urethra, Vagina.
Give appropriate term of the following:
The attachment of developing zygote (blastocyst) on the uterine wall.
Complete the following statement by choosing the correct alternative:
Fertilization occurs in ______.
The following diagram represents the vertical sectional view of the human female reproductive system.
What happens to the uterus, if fertilization fails to take place?
Name the female sex hormones and structures which secrete them.
Give Reasons
The urethra is also called urinogenital duct.
Differentiate
External fertilization and Internal fertilization.
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
Explain the term Cowper’s glands.
Give Technical Term:
Rupture of the follicle and release of the ovum from the ovary.
Give Technical Term:
A method of contraception in which the sperm duct is cut and ligated.
Complete the following sentences with appropriate word:
___________ hormones are secreted by the interstitial cells.
Complete the following sentences with appropriate word:
Fertilization of the human egg by the sperm normally occurs in the_______
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Sperm is a highly motile male gamete.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Fertilization is the product of the egg nucleus and the sperm nucleus.
Explain the mechanism of fertilization in humans.
Define.
Fertilization
How many hours are required for the process of capacitation?
