What could be the reasons for adopting contraceptive methods?
There can be many reasons for adopting contraceptive methods:-
The main reason for adopting the contraceptive methods is birth control or the population control.
Condoms are the safeguard against the infection of AIDS (acquired immune deficiency syndrome) or STD (sexually transmitted diseases)
The induced abortion method of contraception is used to get rid of unwanted pregnancy by the unprotected intercourse, when women get raped by someone, or where mother’s life or foetus is in danger and when women is not able to conceive the baby due to the weak immune system of the baby.
Why is variation beneficial to the species but not necessarily for the individual?
Draw a labelled diagram of the longitudinal section of a flower.
What are the functions performed by the testis in human beings?
Why does menstruation occur?
How will an organism be benefited if it reproduces through spores?
Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?
Asexual reproduction takes place through budding in
(a) amoeba.
(b) yeast.
(c) plasmodium.
(d) leishmania.
How does the embryo get nourishment inside the mother’s body?
What are the advantages of sexual reproduction over asexual reproduction?
What is the importance of DNA copying in reproduction?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the difference between a reflex action and walking?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
What is the difference between a reflex action and walking?
What chemical process is used for obtaining a metal from its oxide?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should curd and sour substances not be kept in brass and copper vessels?
What are the limitations of extracting energy from—
(a) the wind? (b) waves? (c) tides?
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
Define 1 dioptre of power of a lens.
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
Describe the structure and functioning of nephrons.