What are the different methods of contraception?
There are various birth control methods which prevent fertilization (meeting of a sperm to ovum to form a zygote) is known as contraception. There are mainly three major types of contraception:-
Temporary methods
Permanent method
Medical termination of pregnancy
Temporary methods:- they contain natural, barrier or physiological methods of the birth control. In natural, Lactation amenorrhea (absence of menstruation) method is used, where there is intense lactation occurs during the absence of periods in females which prevents from the birth control. In barrier methods- condoms, cervical caps, vaults and Intrauterine devices are used for the contraception. Or, in physiological devices oral pills or injections can be taken for the birth control which confirms the ovulation occurance in females by secreting the FSH (follicle stimulating hormone) or LH (Luteinizing hormone).
Permanent method:- it is a surgical method for the birth control. In man it is known as Vasectomy or in females it is known as tubectomy. Vasectomy is the process of removal of short segment of each vas deferens and tying up of the remaining ends tightly with the surgical thread. And tubectomy is the process of removal of fallopian tube and the remaining ends are tied up tightly with the surgical thread.
Medical termination of pregnancy:- also called induced abortion. It is the voluntary termination of a pregnancy before the foetus making. It is done to get rid of unwanted pregnancy, rapes etc.
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?
The magnification produced by a plane mirror is +1. What does this mean?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is food transported in plants?
How is the amount of urine produced regulated?
Calculate the number of electrons constituting one coulomb of charge.
How is the sex of the child determined in human beings?
What would be the advantages of exploiting resources with short-term aims?
What is an homologous series? Explain with an example.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
Draw the electron dot structures for
(a) ethanoic acid.
(b) H2S.
(c) propanone.
(d) F2.