NCERT Solutions Class 12 Biology Chapter 7 Evolution

NCERT Solutions Class 12 Biology Chapter 7 Evolution

NCERT Solutions Class 12 Biology Chapter 7 Evolution: National Council of Educational Research and Training Class 12 Biology Chapter 7 Solutions – Evolution. NCERT Solutions Class 12 Biology Chapter 7 PDF Download.

NCERT Solutions Class 12 Biology Chapter 7: Overview

Board

NCERT
Class

12

Subject

Biology
Chapter

7

Chapter Name

Evolution
Topic

Exercise Solutions

NCERT Solutions Class 12 Biology Chapter 7 – Evolution

1.) Explain antibiotic resistance observed in bacteria in light of darvinionselection theory.

Answer: According to Darvin’s exeperiment; Darvin first take a sterile plate with medium and grow a bacterium. The population of bacterium was very high. Then inserted an antibiotic in the plate; then very few of the bacteria were able to grow because of development of antibiotic  resistantgeve in them.

2.) Find out from newspapers and popular science articlesany new fossildiscoveries or controversies about evolution.

Answer: One of the popular controverysy were found about Lamarck’s theory on evolution; about evolution of earth. One more scientist the name was Huxley who made a statement that human evolved from apes; but later on by palaentological studies, it was shown that apes and human have a common ancestor.

3.) Attempt giving a clear definition of the term species.

Answer: A species can be defined a group of living thing share a common characteristics. The species can be termed as a group of population have ability of inter breeding under suitable condition.

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

Answer: As the human evolution; a tremendous changes has occurred upto modern man, in terms of brain capacity, size and their diet.

Human type                 Brain capacity

1.) Homo habitis             650-800 cc

2.) Homo erectus            900 cc

3.) Neanderthal man       1400 cc

4.) Homo sapiens              1250 cc

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

Answer: Yes, according to internet and popular science articles, the apes have self-conscionsness such as facial features.

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

Answer:

               Modern day animal                    Ancient fossil
1.) Modern birds a. ) Ornithomimus dinosaur with a wish-bone.
2.) Arthropods like crustaceans, insectsarachinds. b.) trilobites of Palaeozoic era.
3.) Modern man (Homo sapiens sapiens). c.) Cro-mangnon man (H. sapiens fossilis)
4.) Modern elephant. d.) Moeritherium of late Eocene times.
5.) Modern camel( Camelus) e.) Poebrotherium and orocamelus.
6.) Ammonites (Cephalopod molluse) f.) Bacterites of Ordovician period.
7.) Modern horse 9Equus) g.) Dawn horse (Eohippus)
8.) Modern amphibians. h.) Labyrinthodonts (earliest fossilised ambhibians)
9.) Land- dwelling forms. i.) Crossopterygian fishes.
10.) Reptiles. j.) Sregocephalians of carboniferous period.

7.) Describe one example of adaptive radiation.

Answer: Adaptive radiation can be termed as – The species which radiating to another habitat and become adaptive to new environment called as Adaptive radiation. For example – Australian marsupials which belongs to Darwin’s firchess.

8.) Can we call human evolution as adaptive radiation?

Answer:  No human evolution cannot be considered as adaptive radiation because tremendous change in human evolution from Austrapithecus which are African ape like man, to modern man. But descendent with modification.

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

Answer: The evolutionary stages of horse are five stages such as-

1.) Eohippus called as Dawn horse.

2.) Mesohippus called as Intermediate horse.

3.) Merychippus called as Ruminatting horse.

4.) Pilohippus which is closed to modern horse.

5.) Eqqus – modern horse.

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