NCERT Solutions for Class 12 Biology Chapter 7 Evolution

 

NCERT solutions for class 12 biology chapter 7 evolution: What exactly is evolution? To understand the changes in flora and fauna that have occurred over millions of years on earth, we must have an understanding of the context of the origin of life, i.e., the evolution of the earth, of stars and indeed of the universe itself. What follows is the longest of all the construed and conjectured stories. Solutions of NCERT class 12 biology chapter 7 evolution will help you in understanding the story of the origin of life and evolution of life forms or biodiversity on planet earth in the context of the evolution of earth and against the background of the evolution of the universe itself. The origin of life on earth can be understood only against the background of the origin of the universe especially earth. In CBSE NCERT solutions for class 12 biology chapter 7 evolution, you will the easy way to remember the facts. If you are looking for the answers of any other class from 6-12 then NCERT solutions are there for you.

The diversity of life forms on earth has been changing over millions of years. In NCERT solutions for class 12 biology chapter 7 evolution, you will find questions and solutions based on such facts.

Here are the Important topics of NCERT solutions for class 12 biology chapter 7 evolution:

7.1 Origin of Life

7.2 Evolution of Life Forms – A Theory

7.3 What are the Evidences for Evolution?

7.4 What is Adaptive Radiation?

7.5 Biological Evolution

7.6 Mechanism of Evolution

7.7 Hardy-Weinberg Principle

7.8 A Brief Account of Evolution

7.9 Origin and Evolution of Man

Considering the size of the universe, the earth is indeed a speck. In solutions for NCERT class 12 biology chapter 7 evolution, questions are there about the Big Bang Theory. As in this chapter, you will learn about the Big Bang theory which explains the origin of the universe. It talks of a singular huge explosion unimaginable in physical terms. It will also tell you that the universe expanded and hence, the temperature came down.

After going through this chapter that is evolution, you will be able to answer all the questions given at the end of the chapter. And if still confused then CBSE NCERT solutions for class 12 biology chapter 7 evolution is there for you all the time.

Also, try to attempt all the questions given in NCERT, and in case, if you have any doubt then refer to NCERT solutions for class 12 biology chapter 7 evolution. Here you will get all the answers to those questions which are mentioned in this Evolution chapter and it will help you to score good marks in the 12th board exam as well as other competitive exams.

NCERT solutions for class 12 biology chapter 7 evolution: Solved Exercises Questions:

Q 1.     Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.

Answer:

Darwinian selection theory suggests that the environment selects organisms with useful variation over those which do not have useful variations. It is mainly because, in a dynamic environment, these organisms are better adapted to survive. A well-defined example for Darwin's theory is antibiotic resistance in bacteria. When bacteria were grown on penicillin containing agar medium, all the bacteria died, however, the ones having variations conferring penicillin resistance survived. Later, these bacteria multiplied and increased their number. As a result of this, penicillin-resistant bacteria evolved and survived because of the environment that selected these over the others. 

Q2. Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.

Answer:

A recent study suggests Ledumahadi mafube is the fossil from South Africa, that marked the beginning of gigantic dinosaurs. This 200 million-year-old dinosaur weighed around 12 tons, making it the earliest dinosaur to pass beyond the 10-ton threshold. Later, dinosaurs would become even bigger. But in its time, Ledumahadi mafube was a giant among dwarfs (Source- Business standard).

Q3. Attempt giving a clear definition of the term species..

Answer:

The term species refers to a group of individuals that are similar in their characters and can interbreed among themselves and produce viable and fertile progenies.

Q4. Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)

Answer:

The various components of human evolution involve the age of appearance, brain capacity, posture, locomotion, height, body hairs, dietary preferences, skeletal structure, cranium structure etc. A summary of human evolution based on these components is as follows:

 

Name of the Organisms

Brain capacity in cm^{^{3}}

Posture                         

Dietary preferences 

Some other features      

1.

Dryopithecus

  not known

Bent, ape-like 

Soft fruits and leaves

Equal sized arms and legs, large canines

2.

Ramapithecus

not known

Semi-erect, more man-like

seeds and nuts

Large molars, small canines

3.

Australopithecus

500

Fully erect

Herbivorous

Small canines, hunted with stones

5.

Homo habilis

650-800

Fully erect

Carnivorous

Toolmakers with small canines

6.

Homo erectus

900

Fully erect

Omnivorous 

Used tools made of stones and bones

7.

Homo neanderthalnsis

1400

Fully erect

Omnivorous

Cave dwellers used to hide their bodies

8.

Homo sapiens

1200-1600

Fully erect

Omnivorous

Highly intelligent, social

Q5. Find out through internet and popular science articles whether animals other than man has self-consciousness.

Answer:

Self-consciousness is the awareness of an animal towards its surroundings. Other than man, the animals which show self-consciousness are dolphins, orangutans, gorilla, chimps, elephants etc. Even dogs also show subtle consciousness.

Q6. List 10 modern-day animals and using the internet resources link it to a corresponding ancient fossil. Name both.

Answer:

Some modern animals and fossils to which they can be linked are as follows:

 

Name of the animal

Name of the fossils

1. 

Man 

Ramapithecus

2.

Giraffe

Palaeotragus

3.

Tetrapods

Ichthyostega

4.

Fish

Arandaspis

5.

Dog

Leptocyon

6.

Horse

Eohippus

7.

Whale

Protocetus

8.

Bat

Archaeonycteris

9.

Elephant

Moerithers

10.

Camel

Protylopus

 

Q7. Practise drawing various animals and plants.

Answer:

With the help of your teachers try drawing various plants and animals. While drawing, you can draw comparisons between different structures of animals and plants. 

Note- The answer to this question varies according to the students. 

Q8. Describe one example of adaptive radiation.

Answer:

Adaptive radiation refers to the process in which the individuals belonging to a rapidly diversifying group, diverge from their lineage to form new species. Adaptive radiation works on the theory of natural selection. One example of adaptive radiation is Darwin's finches of Galapagos island. These finches were formed from a single diversifying species that came on this geographical region accidentally. The new species diversified and got adapted to the conditions present on this habitat. The different finches developed different eating habits and accordingly developed different beak structures. This further led to their evolution through adaptive radiation.

Q9. Can we call human evolution as adaptive radiation?

Answer:

No, human evolution cannot be called adaptive radiation because, in adaptive radiation, a single species diversifies into new different species, however, in case of human evolution, the gradual evolution of a single species occurred with time.

Q10. Using various resources such as your school library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal, say horse.

Answer:

The evolutionary stages of a horse are as follows: 

Period

Name of the evolutionary stage

Features of the animal                                                     

Eocene

Eohippus

It has 4 toes, all of them are functional. Head and neck are short

Oligocene

Mesohippus

A slight increase in height with 3 toes on each foot

Miocene

Merychippus

It was 100 cm tall with 3 toes on each foot. Molars were present

Pliocene

Pliohippus

It had a single functional toe with a splint in 2 and 4 of each limb. They are 108 cm tall. 

Pleistocene

Eqqus

They have one tow in each foot. For grinding they have molars, and for cutting they have incisors

NCERT Solutions Class 12 – Biology

Chapter 1

NCERT solutions for class 12 biology chapter 1 Reproduction in organisms

Chapter 2

Solutions of NCERT class 12 biology chapter 2 Sexual Reproduction in Flowering Plants

Chapter 3

CBSE NCERT solutions for class 12 biology chapter 3 Human Reproduction

Chapter 4

NCERT solutions for class 12 biology chapter 4 Reproductive Health

Chapter 5

Solutions of NCERT class 12 biology chapter 5 Principles of Inheritance and Variation

Chapter 6

CBSE NCERT solutions for class 12 biology chapter 6 Molecular basis of inheritance

Chapter 7

NCERT solutions for class 12 biology chapter 7 Evolution

Chapter 8

Solutions of NCERT class 12 biology chapter 8 Human health and disease

Chapter 9 

CBSE NCERT solutions for class 12 biology chapter 9 Strategies for Enhancement in Food Production

Chapter 10

NCERT solutions for class 12 biology chapter 10 Microbes in Human Welfare

Chapter 11

Solutions of NCERT class 12 biology chapter 11 Biotechnology: Principles and Processes

Chapter 12

CBSE NCERT solutions for class 12 biology chapter 12 Biotechnology and its Applications

Chapter 13

NCERT solutions for class 12 biology chapter 13 Organisms and Populations

Chapter 14

Solutions of NCERT class 12 biology chapter 14 Ecosystem

Chapter 15

CBSE NCERT solutions for class 12 biology chapter 15 Biodiversity and Conservation

Chapter 16

NCERT solutions for class 12 biology chapter 16 Environmental Issues

NCERT Solutions for Class 12- Subject wise

Solutions for NCERT Class 12 Maths

CBSE NCERT solutions for Class 12 Chemistry

NCERT solutions for  Class 12 Biology

Solutions for NCERT Class 12 Physics

Benefits of NCERT solutions for class 12 biology chapter 7 evolution are given below:

  • It will help you to score good marks in the exams.
  • It will help you to complete your syllabus within the time period.
  • CBSE NCERT solutions for class 12 biology chapter 7 evolution will be very beneficial for the revision of important concepts of this chapter.
  • It will help you to clear your base of NCERT.
  • It will also help you to score good marks in CBSE 12th board exam.
  • NCERT solutions for class 12 biology chapter 7 evolution will also help you in the preparation of NEET along with the board exam.

 

 

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