NCERT Solutions for Class 12 Biology Chapter 13 - Organisms and Populations


NCERT Solutions for Class 12 Biology Chapter 13 - Organisms and Populations: You know that ecology is also a branch of biology and Humboldt is the father of ecology. Ecology is the study of the relationships of living organisms with the abiotic (physicochemical factors) and biotic components (other species) of their environment. It is concerned with four levels of biological organization-organisms, populations, communities, and biomes.

Natural selection is also an interesting topic of NCERT Class 12 Biology Chapter 13 - Organisms and Populations. Evolutionary changes through natural selection take place at the population level and hence, population ecology is an important area of ecology. A population is a group of individuals of a given species sharing or competing for similar resources in a defined geographical area. Populations have attributes that individual organisms do not- birth rates and death rates, sex ratio, and age distribution. The proportion of different age groups of males and females in a population is often presented graphically as age pyramid; its shape indicates whether a population is stationary, growing or declining.

Here the important topics of Chapter 13 - Organisms and Populations of Class 12 Biology (NCERT) is given below:

13.1 Organism and Its Environment

    13.1.1 Major Abiotic Factors

    13.1.2 Responses to Abiotic Factors

    13.1.3 Adaptations

13.2 Populations

    13.2.1 Population Attributes

    13.2.2 Population Growth

    13.2.3 Life History Variation

    13.2.4 Population Interactions

Chapter 13 - Organisms and Populations of NCERT Class 12 Biology will also tell you about growth rate, birth rate, death rate, and immigration of the population. Populations grow through births and immigration and decline through deaths and emigration. When resources are unlimited, the growth is usually exponential but when resources become progressively limiting, the growth pattern turns logistic. In either case, growth is ultimately limited by the carrying capacity of the environment. The intrinsic rate of natural increase (r) is a measure of the inherent potential of a population to grow.

After going through the NCERT Class 12 Biology Chapter 13 - Organisms and Populations line by line, you can answer the questions given below:

  • Q1. An orchid plant is growing on the branch of mango tree. How do you describe this interaction between the orchid and the mango tree?
  • Q2. What is the ecological principle behind the biological control method of managing with pest insects?
  • Q3. Distinguish between the following:
    • (a) Hibernation and Aestivation
    • (b) Ectotherms and Endotherms

If you have any doubt or unable to answer by yourself then, Solutions for NCERT Class 12 Biology of Chapter 13 - Organisms and Populations is there for you to help you out.

Also, try to attempt all the given questions in NCERT, and if still confused or in case, you have any doubt then refer to NCERT Solutions for Class 12 Biology of Chapter 13 - Organisms and Populations. There you will get all the answers to those questions which are mentioned in this chapter and it will help you to score good marks not only in the board exam even in other competitive exams too. 

NCERT Solutions for Class 12 Biology Chapter 13 - Organisms and Populations: Solved Exercise Questions

NCERT Solutions class 12 – Biology

Chapter 1

Reproduction in organisms

Chapter 2

Sexual Reproduction in Flowering Plants

Chapter 3

Human Reproduction

Chapter 4

Reproductive Health

Chapter 5

Principles of Inheritance and Variation

Chapter 6

Molecular basis of inheritance

Chapter 7


Chapter 8

Human health and disease

Chapter 9

Strategies for enhancement in food production

Chapter 10

Microbes in Human Welfare

Chapter 11

Biotechnology: Principles and Processes

Chapter 12

Biotechnology and its applications

Chapter 14


Chapter 15

Biodiversity and Conservation

Chapter 16

Environmental Issues

NCERT Solutions for Class 12- Subject wise

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