Science Biology Notes | Class 12 – Chapter 6: Evolution

You will get here Science Biology class 12 CBSE notes Chapter 6: Evolution. You can connect with us for every important update related to class 12.

Science Biology is a very important subject for you because it will help you increase your percentage as well as it is an important subject for your medical entrance exam. You can score high marks in this subject by studying notes and practicing MCQs. In this post, we will cover Chapter 6: Evolution.

Also Read- Moushumi Chatterjee: Married at 15, Mother at 17 – The Actress Who Even Took On Raaj Kumar

Table of Contents

Key Content Of Chapter 6 Evolution

Evolution is the gradual change in living organisms over time.
It explains the origin and development of life on Earth.
Earth was formed about 4.5 billion years ago.
Life originated through chemical evolution from non-living molecules.
Early atmosphere had gases like methane, ammonia, CO₂, and water vapour.
First life forms were simple, single-celled organisms.
Darwin’s theory of Evolution explains natural selection.
Natural selection = survival of the fittest.
Organisms with better adaptations survive and reproduce more.
Variation is the key factor for Evolution.

Sources of variation:

Mutation
Genetic recombination

Evidences of Evolution:

Fossils
Homologous organs
Analogous organs
Embryological similarities

Homologous organs → same structure, different function (divergent evolution)

Analogous organs → different structure, same function (convergent evolution)

Adaptive radiation = one species evolves into multiple forms in different habitats.
Example: Darwin’s finches

Hardy-Weinberg principle explains genetic equilibrium in populations.

Evolution occurs when this equilibrium is disturbed.

Factors affecting Evolution:

Mutation
Gene flow
Genetic drift
Natural selection

Life evolved from:
Simple cells → multicellular organisms → vertebrates → humans

Human Evolution shows increase in brain size and intelligence over time.

👉 Evolution is the continuous process of change and adaptation of life.

– Pulse by Anubhav 🚀

Also Read- Class 12 Physical Education Notes (Chapter Wise) – CBSE Guide

Class 12 Science Biology Chapter 6: Evolution Notes

Evolution

Class 12 Biology Chapter 6 – Pulse by Anubhav

Evolution chapter life ke origin se lekar human evolution tak ka complete concept clear karta hai. Isme Darwin theory, natural selection, evidences of Evolution, adaptive radiation aur Hardy-Weinberg principle jaise important topics cover hote hain — exam ke liye highly important 🔥

📘 Notes 📄 Book PDF 📑 Syllabus 📢 Telegram

Join Telegram Channel

Class 12 Biology Chapter 6 Evolution MCQs

Evolution (MCQs) – Pulse by Anubhav

1. Evolution is:

A. Sudden growth

B. Gradual change in organisms over time

C. Respiration process

D. Digestion

2. Earth was formed about:

A. 1000 years ago

B. 4.5 billion years ago

C. 1 million years ago

D. 500 years ago

3. First life forms were:

A. Humans

B. Single-celled organisms

C. Plants

D. Mammals

4. Darwin proposed theory of:

A. Mutation

B. Natural selection

C. Respiration

D. Digestion

5. Survival of the fittest means:

A. Strongest organisms survive only

B. Best adapted organisms survive

C. Biggest organisms survive

D. Fastest organisms survive

6. Fossils are:

A. Living organisms

B. Remains of ancient organisms

C. Seeds

D. Cells

7. Homologous organs show:

A. Same function, different structure

B. Same structure, different function

C. No similarity

D. Only size difference

8. Analogous organs show:

A. Same structure

B. Same function, different structure

C. Same origin

D. No function

9. Adaptive radiation example:

A. Human brain

B. Darwin’s finches

C. Photosynthesis

D. Respiration

10. Hardy-Weinberg principle explains:

A. Digestion

B. Genetic equilibrium

C. Respiration

D. Circulation

Score: 0 / 10

Also Read:- Shruti Haasan Profile: Age, Height, Facts & Big Update on Peddi Song with Ram Charan

FAQs About Evolution

Evolution – FAQs (Pulse by Anubhav)

1. What is Evolution?

Evolution is the gradual change in living organisms over time leading to new species.

2. Who proposed the theory of Evolution?

Charles Darwin proposed the theory of Evolution based on natural selection.

3. What is natural selection?

Natural selection is the process where better adapted organisms survive and reproduce more.

4. What are evidences of Evolution?

Fossils, homologous organs, analogous organs, and embryological evidence support Evolution.

5. What is adaptive radiation?

It is the evolution of multiple species from a common ancestor in different habitats.

6. What is Hardy-Weinberg principle?

It states that gene frequency remains constant in a stable population unless disturbed.

Class 12 Biology Notes – All Chapters (Pulse by Anubhav)

Chapter	Topic	Open
Chapter I	Sexual Reproduction in Flowering Plants	View →
Chapter II	Human Reproduction	View →
Chapter III	Reproductive Health	View →
Chapter IV	Principles of Inheritance and Variation	View →
Chapter V	Molecular Basis of Inheritance	View →
Chapter VI	Evolution	View →
Chapter VII	Human Health and Disease	View →
Chapter VIII	Microbes in Human Welfare	View →
Chapter IX	Biotechnology: Principles and Processes	View →
Chapter X	Biotechnology and its Applications	View →
Chapter XI	Organisms and Populations	View
Chapter XII	Ecosystem	View →
Chapter XIII	Biodiversity And Conservation	View →

2 thoughts on “Science Biology Notes | Class 12 – Chapter 6: Evolution”

Pingback: Science Biology Notes | Class 12 – Chapter 12: Ecosystem - Pulse By Anubhav
Pingback: Science Biology Notes | Class 12 – Chapter 1: Sexual reproduction in flowering plants - Pulse By Anubhav