Q15 of 56 Page 1

List and explain in brief three methods of contraception.

The various methods of contraception are as follows:


1. Chemical Methods: The pregnancy can be prevented by changing the hormonal balance of the body due to which the body will not release the eggs and therefore preventing fertilization. The various kind of chemical methods are: Oral pills and vaginal oils. These polls stop the ovary from releasing the ovum into fallopian tube.


2. Surgical Methods: Pregnancy can be prevented by surgeries in both males and females. In case of males, the vas deferens is blocked through surgery and thus the egg is prevented to reach the uterus. It helps in prevention of pregnancy.


3. Barrier Methods: Barrier methods like use of physical devices such as condoms, diaphragm and cervical caps helps in prevention of pregnancy by preventing the sperm entry in female genital tract. Other contraceptive methods are used to prevent pregnancy such as loop or copper-T.


More from this chapter

All 56 →
13

What is meant by homologous series of organic compounds? Write the chemical formulae of two members of a homologous series and state which part determines the (i) physical properties, (ii) chemical properties, of these compounds.

 14

Na, Mg and Al are the elements having one, two and three valence electrons respectively. Which of these elements (i) has the largest atomic radius, (ii) is least reactive? Justify your answer stating reason for each.

 16

If we cross pure-bred tall (dominant) pea plant with pure-bred dwarf (recessive) pea plant we will get pea plants of F1generation. If we now self-cross the pea plant of F1 generation, then we obtain pea plants of F2 generation.

(a) What do the plants of F1 generation look like?


(b) State the ratio of tall plants to dwarf plants in F2 generation.


(c) State the type of plants not found in F1 generation but appeared in F2 generation, mentioning the reason for the same.

 17

List in tabular form two distinguishing features between acquired traits and inherited traits, with one example of each.