Class 12 Biology Organisms and Population: NCERT Solutions for Question 3
Define phenotypic adaptation. Give one example.
Phenotypic adaptation involves changes in the body of an organism in response to genetic mutation or certain environmental changes. These responsive adjustments occur in an organism in order to cope with environmental conditions present in their natural habitats. For example, desert plants have thick cuticles and sunken stomata on the surface of their leaves to prevent transpiration. Similarly, elephants have long ears that act as thermoregulators.
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?
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- 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?
Popular Questions of Class 12 Biology
- Q:- Why is reproduction essential for organisms? Answer
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- 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?
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3 Comment(s) on this Question
It's very easy to learn in short period of time.thanks for the answers.
Good
Excellent explanation
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