How do ecologists estimate the total number of species present in the world?
Solution and Explanation
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.
Top Questions on Biodiversity and Conservation
- Match List-I with List-II:Choose the correct answer from the options given below:
List-I List-II A. Biodiversity hotspot I. Khasi and Jantia hills in Meghalaya B. Sacred groves II. World Summit on Sustainable C. Johannesburg South Africa III. Parthenium D. Alien species invasion IV. Western Ghats - NEET (UG) - 2024
- Biology
- Biodiversity and Conservation
- A strict protection of biodiversity hotspots could reduce the ongoing mass extinction by almost:
- KCET - 2024
- Biology
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- (a) Redraw the pie chart identifying the groups ’A’, ’B’, ’C’, and ’D’ in their respective positions.
(b) Mention two examples of recently extinct animals.
- CBSE CLASS XII - 2024
- Biology
- Biodiversity and Conservation
- Tropical regions harbour more species than the temperate regions. How have biologists tried to explain this in their own ways? Explain.
- CBSE CLASS XII - 2024
- Biology
- Biodiversity and Conservation
- Assertion (A): “Biodiversity hotspots” are the regions which possess high levels of species richness, high degree of endemism.
Reason (R): Total number of biodiversity hotspots in the world is 22 with two of these hotspots found in India.- CBSE CLASS XII - 2024
- Biology
- Biodiversity and Conservation
Questions Asked in CBSE CLASS XII exam
- Using integration, find the area of the region bounded by the line \[ y = 5x + 2, \] the \( x \)-axis, and the ordinates \( x = -2 \) and \( x = 2 \).
- CBSE CLASS XII - 2025
- Evaluation of Definite Integrals by Substitution
- Two conductors A and B of the same material have their lengths in the ratio 1:2 and radii in the ratio 2:3. If they are connected in parallel across a battery, the ratio \( \frac{v_A}{v_B} \) of the drift velocities of electrons in them will be:
- CBSE CLASS XII - 2025
- Current electricity
- Arun, Bashir and Joseph were partners in a firm sharing profits and losses in the ratio of 5 : 3 : 2. They admitted Daksh as a new partner who acquired his share entirely from Arun. If Arun sacrificed \( \frac{1}{5} \)th from his share to Daksh, Daksh's share in the profits of the firm will be :
- CBSE CLASS XII - 2025
- Partnership Accounts
- Consider three metal spherical shells A, B, and C, each of radius \( R \). Each shell has a concentric metal ball of radius \( R/10 \). The spherical shells A, B, and C are given charges \( +6q, -4q, \) and \( 14q \) respectively. Their inner metal balls are also given charges \( -2q, +8q, \) and \( -10q \) respectively. Compare the magnitude of the electric fields due to shells A, B, and C at a distance \( 3R \) from their centers.
- CBSE CLASS XII - 2025
- Electrostatics
- A 1 cm segment of a wire lying along the x-axis carries a current of 0.5 A along the \( +x \)-direction. A magnetic field \( \mathbf{B} = (0.4 \, \text{mT}) \hat{j + (0.6 \, \text{mT}) \hat{k} \) is switched on in the region. The force acting on the segment is:}
- CBSE CLASS XII - 2025
- Magnetic Effects of Current and Magnetism
Concepts Used:
Biodiversity and Conservation
The term ‘biodiversity’ is derived from the two words- ‘bios' which means life and ‘diversity’ i.e, differentiation or variation. Edward Wilson, the sociobiologist was the first to popularise the term ‘biodiversity’ in the year 1992. The term implies the occurrence of various plants and animals along with their variants such as biotypes, ecotypes and genes on earth. In our biosphere, the immense diversity or heterogeneity remains not only at the species level but also, at every level of biological organization that ranges from macromolecules in the cells to biomes.
Biodiversity and Conservation is a topic covered under the fifteenth chapter and Unit 5 of NCERT class 12 biology.