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

In chapter 13, you will study organisms and population. Ecology is the study of the communication that takes place between organisms and their abiotic environment. The four levels of ecology are organisms, populations, communities, and biomes. The chapter discusses the existence of various kinds of organisms in different environments and how they have adapted to it. Here will also learn how the difference in temperature, soil and various other aspects can affect the organisms living in an environment. To help students such as you understand this chapter and score well in exams, we at UrbanPro have come up with NCERT Solutions for Class 12 Biology Chapter 13. Referring to Organisms and Population NCERT Solutions will help you find answers to all your related questions easily.

Let us take a look at the topics that you will study in Class 12 Biology Chapter 13 – Organisms and Populations:

13.1 Organism and Its Environment

13.2 Populations

In this chapter, you will study:

Section 13.1: In this section, you will study the organisms and the environment in which they live. Ecology at the organismic level is the physiological ecology that tries to understand how organisms that are different in nature try to adapt to their environments, adaptations which are not only in terms of survival but also reproduction. Every organism has a defined range of conditions that it can tolerate. In this section, you will also study the various abiotic factors that play a role in the survival and reproduction of organisms. The abiotic factors are:

1. Temperature: This is one of the most important abiotic factors when it comes to the organism and its environment.

2. Water: Water is another crucial factor that influences the lives of all living organisms. Our Earth is made up of 71% water. Although there are places where there is limited water available such as in the desert, the survival of organisms is only possible through special adaptations.

3. Light: The process of photosynthesis which is used by plants to produce food requires sunlight. Light is a source of energy for all living things.

4. Soil: The properties and the nature of soil differ from place to place.

Here, you will also study the responses of living organisms to these abiotic factors.

Even though living organisms are capable of finding alternative methods to survive in extreme conditions, they are also capable of adapting to certain environments by making physiological adjustments, whereas some show adjustments via their behaviours, that is by migrating to a less stressful environment for a short period.

Section 13.2: In this section, you will learn that a population has certain attributes. On the other hand, an individual organism does not have any. A population has birth rates and death rates, whereas an individual species have a number of births and deaths. These rates are referred to as per capita births and deaths.

You will also learn about population growth, the life history of variation, and population interactions in this section. The size of a population is never constant. It continues to change over time which depends on several factors such as the availability of food, predation pressure, and adverse weather.

In this section, you will learn about the interactions which exist between living organisms. They are predation, competition, parasitism, compensation, and mutualism.

For a better understanding of this chapter, refer to Organisms And Populations Class 12 NCERT Solutions.