Class 12 Biology - Chapter Biodiversity and Conservation NCERT Solutions | How do ecologists estimate the total num
How do ecologists estimate the total number of species present in the world?
The diversity of living organisms present on the Earth is very vast. According to an estimate by researchers, it is about seven millions.
The total number of species present in the world is calculated by ecologists by statistical comparison between a species richness of a well studied group of insects of temperate and tropical regions. Then, these ratios are extrapolated with other groups of plants and animals to calculate the total species richness present on the Earth.
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 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
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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?
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- Q:- What are the various public health measures, which you would suggest as safeguard against infectious diseases?
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- 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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Your answers are very easy to learn and understand ... Thanks for help..
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