Class 12th Biology 2012 Set1 Outside Delhi Board Paper Solution
Question 4
Why is it desirable to use unleaded petrol in vehicles fitted with catalytic converters?
Answer
It is desirable to use unleaded petrol in vehicles fitted with catalytic converters because lead will quickly deposit onto the converter, poisoning the catalyst and rendering it worthless in a very short space of time.
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:-
Explain the following terms with example
(a) Co-dominance
(b) Incomplete dominance - Q:- Define and design a test − cross?
- Q:- The second trophic level in a lake is-
(a) Phytoplankton
(b) Zooplankton
(c) Benthos
(d) Fishes - Q:-
Why is the Human Genome project called a mega project?
- Q:- Give three hypotheses for explaining why tropics show greatest levels of species richness.
- Q:- List two essential roles of ribosome during translation.
- Q:- Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed at the end of these two events.
- Q:- What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give reasons for your answer.
- Q:- Outline salient features of carbon cycling in an ecosystem.
- Q:- Most living organisms cannot survive at temperature above 45°C°. How are some microbes able to live in habitats with temperatures exceeding 100°C?