Class 12th Biology 2018 Set1 Delhi Board Paper Solution
How can the scientific understanding of the menstrual cycle of human females help as a contraceptive measure?
Natural method works on the principle of avoiding chances of ovum and sperms meeting. Periodic abstinence is one such method in which the couples avoid on abstain from sexual intercourse from day 10 to 17 to the mentrual cycle, when ovulation could be expected. As chances of fertilization are very high during this period, which is known as the fertile period. Therefore, by abstaining from coitus during the period, the action of conceiving a child could be prevented. So we can say that human female's mentrual period helps as the contraceptive measures.
There are several other methods like the chemical methods which prevents the fertilization during the intercourse: Intrauterine Devices (IUDs), Diaphragm, Condoms, Vault cap etc.
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:- If the sequence of the coding strand in a transcription unit is written as follows:
5-ATGCATGCATGCATGCATGCATGCATGC-3
Write down the sequence of mRNA. - Q:-
Explain the following terms with example
(a) Co-dominance
(b) Incomplete dominance - Q:- Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.
- Q:- Differentiate between:
(a) Hypocotyl and epicotyl
(b) Coleoptile and coleorrhiza
(c) Integument and testa
(d) Perisperm and pericarp - Q:-
Why is the Human Genome project called a mega project?
- Q:-
Secondary producers are
(a) Herbivores
(b) Producers
(c) Carnivores
(d) None of the above - Q:-
What is menstrual cycle? Which hormones regulate menstrual cycle?
- Q:- Explain the Law of Dominance using a monohybrid cross.
- Q:- Can you suggest a method to remove oil (hydrocarbon) from seeds based on your understanding of rDNA technology and chemistry of oil?
- Q:- Describe one example of adaptive radiation.