Class 12th Biology 2016 Set3 Outside Delhi Board Paper Solution
Question 14
Name two hormones that are constituents of contraceptive pills. Why do they have high and effective contraceptive value? Name a commonly prescribed non-steroidal oral pill.
Answer
The two hormones that are constituents of contraceptive pills are:
1. Progestogen
2. Estrogen
They have high and effective contraceptive value as they inhibit ovulation and implantation as well as after the quality survical mucus to retard entry of sperm.
Example: Saheli is a non-steroidal oral pill.
Popular Questions of Class 12th biology
- Q:- What is spermatogenesis? Briefly describe the process of spermatogenesis.
- Q:- Why is reproduction essential for organisms? Answer
- Q:- Write a short note on
(a) Adaptations of desert plants and animals
(b) Adaptations of plants to water scarcity
(c) Behavioural adaptations in animals
(d) Importance of light to plants
(e) Effect of temperature or water scarcity and the adaptations of animals. - Q:- With a neat diagram explain the 7-celled, 8-nucleate nature of the female gametophyte.
- Q:- What is DNA fingerprinting? Mention its application.
- Q:- What is oogenesis? Give a brief account of oogenesis.
- Q:- Describe the structure of a seminiferous tubule.
- Q:- What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.
- Q:- With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.
- Q:- Explain the Law of Dominance using a monohybrid cross.
Recently Viewed Questions of Class 12th biology
- Q:- The second trophic level in a lake is-
(a) Phytoplankton
(b) Zooplankton
(c) Benthos
(d) Fishes - Q:-
Define external fertilization. Mention its disadvantages.
- Q:- Mention any two autosomal genetic disorders with their symptoms.
- Q:- Arrange the following terms in the correct developmental sequence:
- Q:- Select the statement which explains best parasitism.
(a) One organism is benefited.
(b) Both the organisms are benefited.
(c) One organism is benefited, other is not affected.
(d) One organism is benefited, other is affected. - Q:- What are the various public health measures, which you would suggest as safeguard against infectious diseases?
- Q:- Differentiate between:
(a) Hypocotyl and epicotyl
(b) Coleoptile and coleorrhiza
(c) Integument and testa
(d) Perisperm and pericarp - Q:- Discuss briefly the following:
(a) Radioactive wastes
(b) Defunct ships and e-wastes
(c) Municipal solid wastes - Q:- Which one of the following has the largest population in a food chain?
(a) Producers
(b) Primary consumers
(c) Secondary consumers
(d) Decomposers - Q:- Which property of DNA double helix led Watson and Crick to hypothesise semi-conservative mode of DNA replication? Explain.