Class 12 Biology - Chapter Biodiversity and Conservation NCERT Solutions | What criteria should one use in categori
What criteria should one use in categorizing a species as threatened?
Species that belongs to critically endangered, endangered and vulnerable categories is known as threatened species. There is a range of quantitative criteria and meeting any one of these, qualifies the species for the list at the level of threat. Following criteria have been used:
- Habitat loss or modification
- Increasement in predators or poachers
- Faces high risk of extinction: number of individuals of species declining by the fear or terror (alarming pace).
More Questions From Class 12 Biology - Chapter Biodiversity and Conservation
- Q:- What are sacred groves? What is their role in conservation?
- Q:- Give three hypotheses for explaining why tropics show greatest levels of species richness.
- Q:- The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved greater diversification?
- Q:- How do ecologists estimate the total number of species present in the world?
- Q:- How is biodiversity important for ecosystem functioning?
- Q:- What are the major causes of species losses in a geographical region?
- Q:- What is the significance of the slope of regression in a species − area relationship?
- Q:- Can you think of a situation where we deliberately want to make a species extinct? How would you justify it?
- Q:- Among the ecosystem services are control of floods and soil erosion. How is this achieved by the biotic components of the ecosystem?
- Q:- Name the three important components of biodiversity.
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:- What is the ecological principle behind the biological control method of managing with pest insects?
- Q:- Define spermiogenesis and spermiation.
- Q:- The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form:
(a) MALT
(b) CMI
(c) AIDS
(d) NACO
(e) HIV - Q:- Can we call human evolution as adaptive radiation?
- Q:- Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
- Q:- Give examples to prove that microbes release gases during metabolism.
- Q:- Higher organisms have resorted to sexual reproduction in spite of its complexity. Why?
- Q:- Arrange the following terms in the correct developmental sequence:
- Q:- Suggest the aspects of reproductive health which need to be given special attention in the present scenario.
- Q:- Differentiate the following and give examples of each:
(a) Innate and acquired immunity
(b) Active and passive immunity
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