Class 12 Biology - Chapter Organisms and Population NCERT Solutions | Most living organisms cannot survive at
Most living organisms cannot survive at temperature above 45°C°. How are some microbes able to live in habitats with temperatures exceeding 100°C?
Archaebacteria (Thermophiles) are ancient forms of bacteria found in hot water springs and deep sea hydrothermal vents. They are able to survive in high temperatures (which far exceed 100°C) because their bodies have adapted to such environmental conditions. These organisms contain specialized thermo-resistant enzymes, which carry out metabolic functions that do not get destroyed at such high temperatures.
More Questions From Class 12 Biology - Chapter Organisms and Population
- 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:- If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?
- Q:- Name important defence mechanisms in plants against herbivory.
- Q:- How is diapause different from hibernation?
- Q:- Distinguish between the following:
(a) Hibernation and Aestivation
(b) Ectotherms and Endotherms - Q:- If a marine fish is placed in a fresh water aquarium, will the fish be able to survive? Why or why not?
- Q:- List any three important characteristics of a population and explain
- Q:- List the attributes that populations but not individuals possess.
- Q:- An orchid plant is growing on the branch of mango tree. How do you describe this interaction between the orchid and the mango tree?
- Q:- Give an example for:
(a) An endothermic animal
(b) An ectothermic animal
(c) An organism of benthic zone
Popular Questions of Class 12 Biology
- Q:- Why is reproduction essential for organisms? Answer
- Q:- Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________. - Q:- What do you think is the significance of reproductive health in a society?
- Q:- Mention the advantages of selecting pea plant for experiment by Mendel.
- Q:- Group the following as nitrogenous bases and nucleosides:
Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine. - Q:- Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
- Q:- What are the various public health measures, which you would suggest as safeguard against infectious diseases?
- Q:- Explain in brief the role of animal husbandry in human welfare.
- Q:- Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes under a microscope, which sample would you carry and why?
Recently Viewed Questions of Class 12 Biology
- Q:- Differentiate the following and give examples of each:
(a) Innate and acquired immunity
(b) Active and passive immunity - Q:- Draw a well-labelled diagram of an antibody molecule.
- Q:-
What is meant by monosporic development of female gametophyte?
- Q:- Give three hypotheses for explaining why tropics show greatest levels of species richness.
- Q:- How is sex determined in human beings?
- Q:- Explain the role of tapetum in the formation pollen-grain wall.
- Q:- How many eggs are released by a human ovary in a month?
How many eggs do you think would have been released if the mother gave birth to identical twins?
Would your answer change if the twins born were fraternal? - Q:- Briefly describe the following:
(a) Transcription
(b) Polymorphism
(c) Translation
(d) Bioinformatics - Q:- Differentiate between a zoospore and a zygote.
- Q:- Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished.
4 Comment(s) on this Question
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