Class 12 Biology Chapter 11 Organisms And Populations Notes (Short and Handwritten Notes PDF)

Hi students,

If you are a class 12 student and looking for a nice and simple notes for chapter 11 “Organisms And Populations” then you are at the right place. This chapter is very important for board exams, and our notes will make your preparation extremely easy.

These notes are specially created by analyzing NCERT latest syllabus and last 10 years board exam question papers.

In this article, we have given complete notes of Class 12 Biology Chapter 11 Organisms And Populations(NCERT Class 12 Biology). In this note, every point is written in easy language so that you can understand this lesson easily. This note is based on NCERT. That is, this note is useful for all those children who study NCERT in English medium.

Here we have given the Notes in PDF format which you can download so that you can print it and save your time. To download, click on the given Download PDF link.

Organisms And Populations Notes PDF Download

Important topics covered in the notes

• Major Abiotic Factors:
  • Temperature
  • Water
  • Light
  • Soil
• Responses to Abiotic Factors:
  • Regulate
  • Conform
  • Migrate
  • Suspend
• Adaptations
• Populations
• Population Attributes:
  • Birth Rate and Death Rate
  • Sex Ratio
  • Age Pyramid
• Population Growth:
  • Growth Models:
    • Exponential Growth
    • Logistic Growth
• Population Interactions:

Organisms And Populations Notes- lesson summary

1. Ecology deals with interactions among different organisms and their environment.
2. Abiotic Factors
   • Temperature− It is the most relevant abiotic factor since all organisms require an optimum temperature for their metabolism and other body functions.
   • Water− Water also is a major influencing factor.
   • Soil− The nature and composition of soil differs from one place to another depending upon the climate, weathering process, and soil development method
3. Responses to Abiotic Factors–
   • Regulate− Certain animals have the ability to maintain a constant temperature and a constant osmolarity to keep up their homeostasis
   • Conform− Animals and plants except mammals do not have a constant body temperature and their body temperature changes in accordance with the outside temperature
4. Adaptations-Adaptations are certain characteristics that organisms develop in order to survive and reproduce better in their habitat.
5. Population-It is a group of similar individuals living in a geographical area, sharing similar resources, and capable of interbreeding.
6. Population Growth-The size of a population is an ever changing aspect since it depends upon availability of food, predation, weather conditions, etc
7. Exponential Growth− When the resources are unlimited, population tends to grow in an exponential pattern.
8. Life History Variations-Populations tend to increase their reproductive fitness in order to survive better. This is known as Darwinian fitness (high r value).
9. Population Interactions-A natural habitat consists of many organisms living together and these organisms communicate and interact with each other.
10. Commensalism− In this interaction, one of the partners is benefited while the other is neither benefited nor harmed.

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