10th Science Book Back Answers Unit 19 – Origin And Evolution Of Life:

Samacheer Kalvi 10th Standard Science Book Back Questions with Answers PDF uploaded and the same is given below. Class-tenth candidates and those preparing for TNPSC exams can check the New Science Book Back Question and Answers PDF below.  Samacheer Kalvi Class 10th Std Science Book Back Answers Biology Unit 19 – Origin and Evolution of Life Solutions are available below. Complete solutions for all 23 Units’ book back questions with a solutions guide uploaded and available on our site. Check the complete Samacheer Kalvi 10th Science Unit 19 Answers below:

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Samacheer Kalvi 10th Science Book Back Answers Biology Unit 19 – Origin And Evolution Of Life:

Samacheer Kalvi 10th Science Book Subject One Mark, Two Mark Guide questions and answers are below. Check Science Book Back Questions with Answers. Take the printout and use it for exam purposes.

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10th Science – Biology

Unit 19: Origin And Evolution Of Life

I. Choose the best answer:

1. Biogenetic law states that
a) Ontogeny and phylogeny go together
b) Ontogeny recapitulates phylogeny
c) Phylogeny recapitulates ontogeny
d) There is no relationship between phylogeny and ontogeny
Ans: (b) Ontogeny recapitulates phylogeny

2. The ‘use and disuse theory’ was proposed by.
a) Charles Darwin b) Ernst Haeckel
c) Jean Baptiste Lamarck d) Gregor Mendel
Ans: (c) Jean Baptiste Lamarck

3. Palaeontologists deal with
a) Embryological evidence   b) Fossil evidence
c) Vestigial organ evidence  d) All the above
Ans: (b) Fossil evidence

4. The best way of direct dating fossils of recent origin is by
a) Radio–carbon method b) Uranium lead method
c) Potassium–argon method d) Both (a) and (c)
Ans: (a) Radiocarbon method

5. The term Ethnobotany was coined by
a) Khorana   b. J.W. Harsbberger   c) Ronald Ross   d. Hugo de Vries
Ans: (b) J.W. Harsbberger

II. Fill in the blanks:

1. The characters developed by the animals during their lifetime, in response to the environmental changes are called ______.
Ans.: Adaptation

2. The degenerated and non-functional organs found in an organism are called _______.
Ans.: Vestigial

3. The forelimb of bats and humans are examples of organs.
Ans.: Homologous

4. The theory of natural selection for evolution was proposed by ________.
Ans.: Charles Darwin

III. True or False (Correct the Statement if it is false)

1. The use and disuse theory of organs’ was postulated by Charles Darwin.
Ans: False. The use and disuse theory of organs’ was postulated by Jean Baptiste Lamarck.

2. The homologous organs look similar and perform similar functions but they have different origin and developmental pattern.
Ans: False. The analogous organs look similar and perform similar functions but they have different origin and developmental pattern.

3. Birds have evolved from reptiles.
Ans: True.

IV. Match the following:

Question.

Answer:

1. (c) rudimentary tail and thick hair on the body
2. (a) caudal vertebrae and vermiform appendix
3. (d) a wing of a bat and a wing of an insect
4. (b) a forelimb of a cat and a bat’s wing
5. (f) Thiruvakkarai
6. (e) radiocarbon dating.

V. Answer in Sentence (1 mark):

1. A human hand, a front leg of a cat, a front flipper of a whale, and a bat’s wing look dissimilar and adapted for different functions. What is the name given to these organs?
Ans: Homologous organs.

2. Which organism is considered to be a fossil bird?
Ans: Archaeopteryx is considered to be a fossil bird.

3. What is the study of fossils called?
Ans: The study of fossils is called Palaeontology.

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