Breeding and Biotechnology

Samacheer Book Back Questions And Answers For Science Standard 10 “Breeding and Biotechnology“

I. Choose the correct answer:
1. Which method of crop improvement can be practised by a farmer if he is inexperienced?
a. clonal selection
b. mass selection
c. pureline selection
d. hybridisation

2. Pusa Komal is a disease resistant variety of _____.
a. sugarcane
b. rice
c. cow pea
d. maize

3. Himgiri developed by hybridisation and selection for disease resistance against rust pathogens is a variety of _____.
a. chilli
b. maize
c. sugarcane
d. wheat

4. The miracle rice which saved millions of lives and celebrated its 50th birthday is _____.
a. IR 8
b. IR 24
c. Atomita 2
d. Ponni

5. Which of the following is used to produce products useful to humans by biotechnology techniques?
a. enzyme from organism
b. live organism
c. vitamins
d. both (a) and (b)

6. We can cut the DNA with the help of
a. scissors
b. restriction endonucleases
c. knife
d. RNAase

7. rDNA is a
a. vector DNA
b. circular DNA
c. recombinant of vector DNA and desired DNA
d. satellite DNA

8. DNA fingerprinting is based on the principle of identifying _____ sequences of DNA
a. single stranded
b. mutated
c. polymorphic
d. repetitive

9. Organisms with modified endogenous gene or a foreign gene are also known as
a. transgenic organisms
b. genetically modified
c. mutated
d. both a and b

10. In a hexaploid wheat(2n = 6 x = 42) the haploid (n) and the basic(x) number of chromosomes respectively are
a. n = 7 and x = 21
b. n = 21 and x = 21
c. n = 7 and x = 7
d. n = 21 and x = 7

II. Fill in the blanks:
1. Economically important crop plants with superior quality are raised by _____.
2. A protein rich wheat variety is _____.
3. _____ is the chemical used for doubling the chromosomes.
4. The scientific process which produces crop plants enriched with desirable nutrients is called _____.
5. Rice normally grows well in alluvial soil, but _____ is a rice variety produced by mutation breeding that grows well in saline soil.
6. _____ technique made it possible to genetically engineer living organism.
7. Restriction endonucleases cut the DNA molecule at specific positions known as _____.
8. Similar DNA fingerprinting is obtained for _____.
9. _____ cells are undifferentiated mass of cells.
10. In gene cloning the DNA of interest is integrated in a _____.

Answers:
1. plant breeding
2. Atlas 66
3. Colchicine
4. fortification
5. atomita 2
6. Gene therapy
7. restriction site
8. identical twins
9. Callus
10. vector

III. State whether true or false. If false, write the correct statement
1. Raphano brassica is a man-made tetraploid produced by colchicine treatment.
2. The process of producing an organism with more than two sets of chromosome is called mutation.
3. A group of plants produced from a single plant through vegetative or asexual reproduction are called a pureline.
4. Iron fortified rice variety determines the protein quality of the cultivated plant.
5. Golden rice is a hybrid.
6. Bt gene from bacteria can kill insects.
7. In vitro fertilisation means the fertilisation done inside the body.
8. DNA fingerprinting technique was developed by Alec Jeffrey.
9. Molecular scissors refers to DNA ligases.

Answers:
1. True
2. False (The process of producing an organism with more than two sets of chromosome is called polyploidy)
3. False (A group of plants produced from a single plant through vegetative or asexual reproduction are called a Clone)
4. False (Amino acid rich fortified rice variety containing more amino acids determines the protein quality of the cultivated plant)
5. False (Golden rice is a genetically modified plant)
6. False (Bt gene from bacteria produces a toxin that can kill insects)
7. False (In vitro fertilisation means the fertilisation taking place outside the body by artificial means)
8. True
9. False (Molecular scissors refers to restriction endonucleases)

IV. Match the following:
1. Sonalika               A. Phaseolus mungo
2. IR 8                      B. Sugarcane
3. Saccharum          C. Semi-dwarf wheat
4. Mung No. 1         D. Ground nut
5. TMV – 2               E. Semi-dwarf Rice
6. Insulin                  F. Bacillus thuringienesis
7. Bt toxin                G. Beta carotene
8. Golden rice          H. first hormone produced using rDNA technique

Answers:
1. C
2. E
3. B
4. A
5. D
6. H
7. F
8. G

V. Understand the assertion statement, justify the reason given and choose the correct choice
1. Assertion: Hybrid is superior than either of its parents.
Reason: Hybrid vigour is lost upon inbreeding.
a. Assertion is correct and reason is wrong
b. Reason is correct and the assertion is wrong
c. Both assertion and reason is correct
d. Both assertion and reason is wrong.

2. Assertion: Colchicine reduces the chromosome number.
Reason: It promotes the movement of sister chromatids to the opposite poles.
a. Assertion is correct and reason is wrong
b. Reason is correct and the assertion is wrong
c. Both assertion and reason is correct
d. Both assertion and reason is wrong.

3. Assertion: rDNA is superior over hybridisation techniques.
Reason: Desired genes are inserted without introducing the undesriable genes in target organisms.
a. Assertion is correct and reason is wrong
b. Reason is correct and the assertion is wrong
c. Both assertion and reason is correct
d. Both assertion and reason is wrong.

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