Class 12th Biology 2016 Set1 Delhi Board Paper Solution
Question 1
According to De-Vries what is saltation?
Answer
According to De-Vries, saltation is a single step large mutation that leads to speciation.
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:- Name the functions of the following.
(a) Corpus luteum
(b) Endometrium
(c) Acrosome
(d) Sperm tail
(e) Fimbriae - Q:- Draw a labeled diagram of a section through ovary.
- Q:- Offspring formed due to sexual reproduction have better chances of survival. Why? Is this statement always true?
- Q:- Name the primary and secondary lymphoid organs.
- Q:- Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer.
Biogas, Citric acid, Penicillin and Curd - Q:- Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
- Q:- Correct the following statements:
(a) Surgical methods of contraception prevent gamete formation.
(b) All sexually transmitted diseases are completely curable.
(c) Oral pills are very popular contraceptives among the rural women.
(d) In E. T. techniques, embryos are always transferred into the uterus. - Q:- List the harmful effects caused by alcohol/drug abuse.
- Q:- Which property of DNA double helix led Watson and Crick to hypothesise semi-conservative mode of DNA replication? Explain.
- Q:- Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?