Give an example for:
(a) An endothermic animal
(b) An ectothermic animal
(c) An organism of benthic zone
Give an example for:
(a) An endothermic animal
(b) An ectothermic animal
(c) An organism of benthic zone
Solution and Explanation
(a) Endothermic animal: Birds such as crows sparrows pigeons cranes etc. and mammals such as bears cows rats rabbits etc. are endothermic animals.
(b) Ectothermic animal: Fishes such as sharks amphibians such as frogs and reptiles such as tortoise snakes and lizards are ectothermic animals.
(c) Organism of benthic zone: Decomposing bacteria is an example of an organism found in the benthic zone of a water body.
Top Questions on Organisms and Populations
- (a) Draw a graph for a population whose population density has reached the carrying capacity.
(b) Out of the two population growth curves, which one is considered a more realistic for most populations? Why?
(c) Draw a growth curve where resources are not limiting for the growth of a population and give its equation.
- CBSE CLASS XII - 2025
- Biology
- Organisms and Populations
Student to attempt either option (A) or (B):
(A) How is the interaction between Ophrys and its specific bee pollinator one of the best examples of co-evolution? Explain.
OR
(B) Arrange the given important steps of decomposition in their correct order of occurrence in the breakdown of complex organic matter and explain the fourth step in the process.- CBSE CLASS XII - 2025
- Biology
- Organisms and Populations
- A biologist studied the population of rats in a granary. He found the average natality was 280, average mortality was 200, immigration was 40 and emigration was 50. The net increase in population is:
- CBSE CLASS XII - 2025
- Biology
- Organisms and Populations
Answer the following questions:
- [(i)] Describe the population growth curve applicable in a population of any species in nature that has unlimited resources at its disposal.
- [(ii)] Explain the equation of this growth curve.
- [(iii)] Name the growth curve and depict a graphical plot for this type of population growth.
- [(i)] Explain the conclusion drawn by Alexander von Humboldt during his extensive explorations in the wilderness of South American jungles.
- [(ii)] Give the equation of the Species-Area relationship.
- [(iii)] Draw a graphical representation of the relation between species richness and area for a wide variety of taxa such as birds, bats, etc.
- CBSE CLASS XII - 2025
- Biology
- Organisms and Populations
Student to attempt either option (A) or (B):
(A) Explain how the interaction between a fig tree and its tight one-to-one relationship with the pollinator species of wasp is one of the best examples of mutualism.
OR
(B) Correctly depict (also indicate the trophic level) and describe the ecological pyramid of number with 32 birds dependent on 20 insects feeding on one banyan tree.- CBSE CLASS XII - 2025
- Biology
- Organisms and Populations
Questions Asked in CBSE CLASS XII exam
- (a) Find the point Q on the line \( \frac{2x + 4}{6} = \frac{y + 1}{2} = \frac{-2z + 6}{-4} \) at a distance of \( \frac{\sqrt{5}}{2} \) from the point \( P(1, 2, 3) \).
- CBSE CLASS XII - 2025
- Coordinate Geometry
- For a positive constant \( a \), differentiate \( \left( t + \frac{1}{t} \right)^a \) with respect to \( t \), where \( t \) is a non-zero real number.
- CBSE CLASS XII - 2025
- Differentiation
Complete and balance the following chemical equations: (a) \[ 2MnO_4^-(aq) + 10I^-(aq) + 16H^+(aq) \rightarrow \] (b) \[ Cr_2O_7^{2-}(aq) + 6Fe^{2+}(aq) + 14H^+(aq) \rightarrow \]
- CBSE CLASS XII - 2025
- Redox Reactions
- Pulkit and Ravinder were partners in a firm sharing profits and losses in the ratio of 3 : 2. Sikander was admitted as a new partner for \( \frac{1}{5} \)th share in the profits of the firm. Pulkit, Ravinder and Sikander decided to share future profits in the ratio of 2 : 2 : 1. Sikander brought Rs 5,00,000 as his capital and Rs 10,00,000 as his share of premium for goodwill. The amount of premium for goodwill that will be credited to the old partners' capital accounts will be :
- CBSE CLASS XII - 2025
- Partnership Accounts
- What is the term used for the milk produced during the initial days of lactation?
- CBSE CLASS XII - 2025
- human health and disease
Concepts Used:
Organisms and Populations
Organisms:
An attached living system that lives in an environment is commonly known as an organism. These organisms are able to retain certain behaviors and structures. Some examples of organisms are plants, animals, bacteria, fungi, and humans. A group of these organisms leads to the formation of a population. The collection of the population forms a community that assists in the operation of ecosystems.
Each and every organism has the ability to adapt itself to various conditions of the environment. This capacity of organisms is due to their genetic variations. It is due to this only that their probability of survival get increases. For instance, camels adapt themselves to survive in desert areas and polar bears adapt to the extreme cold conditions or situations through their dense fur coat.
Populations:
A collection of organisms or individuals of a species that live, at a specific time, in a geographical area that is well-defined and capable of interbreeding is described as a population.
Read More: Organisms and Populations