NCERT Solutions For Class 12 Biology Chapter 13: Organisms and Population

Jasmine Grover logo

Jasmine Grover Content Strategy Manager

Content Strategy Manager

NCERT Solutions for Class 12 Biology Chapter 13 Organisms and Population are provided in this article. This Chapter 13 comes under Unit X- Ecology and Environment. The article will provide all the important definitions, concepts, and methodologies that will be really beneficial for the students appearing for CBSE Class 12 Exam 2022-23. The important topics that are included in this chapter are:

Expected no. of Questions: 1-2 questions of around 3 marks.

Download PDF: NCERT Solutions for Class 12 Biology Chapter 13 Organisms and Populations


NCERT Solutions for Class 12 Biology Chapter 13

NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics NCERT Solutions Physics

Class 12 Biology Chapter 13 Organisms and Populations: Important Topics

The branch of biology involving the study of the interactions that take place between an organism and its environment is known as ecology. Any biological organization consists of 4 levels which are as Organisms, Populations, Biomes, and Communities. Let us know more about the first two levels that are- Organisms, and Populations. 

  • Organisms

An organism can be defined as a contiguous living system that lives in an environment and has the ability to adapt and retain certain structures and behaviour. For instance, fungi, bacteria, plants, animals, and humans. An organism collectively forms a population. 

  • Populations

The population is referred to as a group of individuals or organisms of any species living in a well–defined geographical area, at a specific time with the capability of interbreeding. For example, the population of deer in a forest.

  • Population Interactions

Population interactions are referred to as the interaction between different populations. There are various modes of population interactions. These include:

  • Predation: In this is a type of interaction an organism kills and feeds on another organism. The one who kills is the predator and the one who is killed is the prey.
  • Competition: This is the type of biological interaction that takes place between different animals or species in which both are harmed.
  • Parasitism: It is a type of interaction between species wherein the parasite lives inside the body of another organism and causes harm to it.
  • Commensalism: In this type of interaction, one organism benefits while the other is neither benefitted nor harmed.
  • Mutualism: This type of interaction occurs in both the species or organisms who are benefitted from each other.

Also Read:

Check-Out: 

CBSE CLASS XII Related Questions

  • 1.

    Student to attempt either option-(A) or (B):
    (A) Write the features a molecule should have to act as a genetic material. In the light of the above features, evaluate and justify the suitability of the molecule that is preferred as an ideal genetic material. 
    OR 
    (B) Differentiate between the following:

    • [(i)] Polygenic Inheritance and Pleiotropy
    • [(ii)] Dominance, Codominance and Incomplete dominance


      • 2.

        Flowering plants with hermaphrodite flowers have developed many reproductive strategies to ensure cross-pollination. Study the given outbreeding devices adopted by certain flowering plants and answer the questions that follow.

        Note : All plants belong to the same species. No pollen tube growth/inhibition of pollen germination on stigma. Pollen germination on stigma.

        • [(a)] Name and define the outbreeding device described in the above table.
        • [(b)] Explain what would have been the disadvantage to the plant in the absence of the given strategy.


          • 3.

            Given below is a heterogeneous RNA formed during Eukaryotic transcription:

            heterogeneous RNA

            How many introns and exons respectively are present in the hnRNA?

              • 7, 7
              • 8, 7
              • 8, 8
              • 7, 8

            • 4.
              Enlist three advantages of genetically modified plants.


                • 5.

                  Study the given below single strand of deoxyribonucleic acid depicted in the form of a “stick” diagram with 5′ – 3′ end directionality, sugars as vertical lines and bases as single letter abbreviations and answer the questions that follow.

                  Name the covalent bonds depicted as (a) and (b) in the form of slanting lines in the diagram.
                  How many purines are present in the given “stick” diagram?
                  Draw the chemical structure of the given polynucleotide chain of DNA.


                    • 6.
                      Student to attempt either option (A) or (B):
                      (A)
                      (i) Explain why the milk produced by the mother during the initial days of lactation is considered to be very essential for the newborn infant.
                      (ii) What is the term used for the milk produced during the initial days of lactation?
                      OR
                      (B) Many children in the metro cities are suffering from a very common exaggerated response of the immune system to certain weak antigens in air.
                      (i) What is the term used for the above mentioned disease?
                      (ii) Name the main type of antibody produced by the immune system in response to this disease.
                      (iii) Which two main inflammation-causing chemicals are produced by the mast cells in such an immune response?

                        CBSE CLASS XII Previous Year Papers

                        Comments


                        No Comments To Show