Text Book Back Questions and Answers - Chapter 9 Plant Breeding 12th Botany Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

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On April 24, 2024, 11:35 AM

Samacheer Kalvi 12th Bio Botany Solutions Chapter 9 Plant Breeding - Text Book Back Questions and Answers

Text Book Back Questions and Answers

I. Choose the correct answer

Question 1.
Assertion : Genetic variation provides the raw material for selection.
Reason : Genetic variations are differences in genotypes of the individuals.
a) Assertion is right and reason is wrong.
b) Assertion is wrong and reason is right.
c) Both reason and assertion is right.
d) Both reason and assertion is wrong.
Answer:
b) Assertion is wrong and reason is right.

Question 2.
While studying the history of domestication of various cultivated plants ………………. were recognized earlier.
a) Centres of origin
b) Centres of domestication
c) Centres of hybrid
d) Centres of variation
Answer:
a) Centres of origin

Question 3.
Pick out the odd pair …………..
a) Mass selection – Morphological characters
b) Purline selection – Repeated self pollination
c) Clonal selection — Sexually propagated
d) Natural selection – Involves nature
Answer:
c) Clonal selection – Sexually propagated

Question 4.
Match Column I with Column II

Answer:
b) i -III, ii-I, iii-IV, iv-II

Question 5.
The quickest method of plant breeding is
a) Introduction
b) Selection
c) Hybridization
d) Mutation breeding
Answer:
b) Selection

Question 6.
Desired improved variety of economically useful crops are raised by
a) Natural selection
b) hybridization
c) mutation
d) biofertilisers
Answer:
b) hybridization

Question 7.
Plants having similar genotypes produced by plant breeding are called
a) clone
b) haploid
c) autopolyploid
d) genome
Answer:
a) clone

Question 8.
Importing better varieties and plants from outside and acclimatising them to local environment is called
a) cloning
b) heterosis
c) selection
d) introduction
Answer:
d) Introduction

Question 9.
Dwarfing gene of wheat is
a) pal 1
b) Atomita 1
c) Norin 10
d) pelita 2
Answer:
c) Norin 10

Question 10.
Crosses between the plants of the same variety are called
a) interspecific
b) inter varietal
c) intra varietal
d) inter generic
Answer:
c) Intra varietal

Question 11.
Progeny obtained as a result of repeat self pollination a cross pollinated crop to called
a) pure line
b) pedigree line
c) inbreed line
d) heterosis
Answer:
b) Pure line

Question 12.
Jaya and Ratna are the semi dwarf varieties of
a) wheat
b) rice
c) cowpea
d) mustard
Answer:
b) Rice

Question 13.
Which one of the following are the species that are crossed to give sugarcane varieties with high sugar, high yield, thick stems and ability to grow in the sugarcane belt of North India?
a) Saccharum robustum and Saccharum officinarum
b) Saccharum barberi and Saccharum officinarum
c) Saccharum sinense and Saccharum officinarum
d) Saccharum barberi and Saccharum robustum
Answer:
b)Saccharum barberi and Saccharum officinarum

Question 14.
Match column I (crop) with column II (Corresponding disease resistant variety) and select the correct option from the given codes.

Answer:
b) I-(ii), II-(i), IH-(iii), IV-(iv)

Question 15.
A Wheat variety, Atlas 66 which has been used as a donor for improving cultivated wheat, which is rich in
a) iron
b) carbohydrates
c) proteins
d) vitamins
Answer:
c) proteins

Question 16.
Which one of the following crop varieties correct matches with its resistance to a disease

Answer:
a) Pusa Komal – Bacterial blight

Question 17.
Which of the following is incorrectly paired?
a) Wheat – Himgiri
b) Milch breed – Sahiwal
c) Rice – Ratna
d) Pusa Komal – Brassica
Answer:
d) Pusa Komal – Brassica

Question 18.
Match list I with list II

a. i c, ii a, iii b, iv d
b. i d, ii c, iii a, iv b
c. i a, ii c, iii b, iv d,
d. i b, ii a, iii d, iv c
Answer:
b. i d, ii c, iii a, iv b

Question 19.
Differentiate primary introduction from secondary introduction
Answer:

Question 20.
How are microbial innoculants used to increase the soil fertility?
Answer:

Biofertilizers or microbial innoculants are defined as preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants uptake of nutrients by their interactions in the rhizosphere when applied through seed or soil.

They are efficient in fixing nitrogen, solubilising phosphate and decomposing cellulose. They are designed to improve the soil fertility, plant growth, and also the number and biological activity of beneficial microorganisms in the soil. They are ecofriendly organic agro inputs and are more efficient and cost effective than chemical fertilizers.

Question 21.
What are the different types of hybridization?
Answer:
Types of hybridization:

(i) Intravarietal hybridization:
The cross between the plants of same variety. such crosses are useful only in the self. pollinated crops.

(ii) Intervarietal hybridization:
The cross between the plants belonging to two different varieties of the same species and is also known as intraspecific hybridization.

(iii) Interspecific hybridization:
The cross between the plants belonging to different species belonging to the same genus is also called intragenic hybridization.
Example:
Gossypium hirsutum
Gossypium arboreum

(v) Intergeneric hybridization:

• The crosses are made between the plants belonging to two different genera.
• The disadvantages are hybrid sterility time consuming and expensive procedure.
  Example : Raphanobrassica x Triticale

Question 22.
Explain the best suited type followed by plant breeders at present?
Answer:
Mutation breeding represents a new method of conventional breeding procedures as they have the advantage of improving the defect without losing an agronomic and quality character in agriculture and crop improvement. Mutation means the sudden heritable changes in the genotype or phenotype of an organism. Gene mutations are of considerable importance in plant breeding as they provide essential inputs for evolution as well as for recombination and selection. It is the only method for improving seedless crops.

Question 23.
Write a note on heterosis.
Answer:

• The superiority of the FI hybrid in performance over its parents is called heterosis or hybird vigour.
• G.H. Shull was the first scientist to use the term heterosis in 1912.
• Heterosis are of the following types.
• Euheterosis, Mutational Euheterosis, Balanced Euheterosis and Pseudoheterosis

(i) Euheterosis:
This is the true heterrosis which is inherited and is further classified as.

(a) Mutational Euheteosis:
Simplest type of euheterosis and results from the sheltering or eliminating of the deleterious unfavourable often lethal, recessive, mutant genes by their adaptively superior dominant alleles in cross pollinated crops.

(b) Balanced Euheterosis :
well balanced gene combinations which is more adaptive to environmental conditions and agricultural usefulness.

(ii) Psuedohetrosis:
Also termed as luxuriance progeny possess superiority over parents in vegetative growth but not in yield and adaptation usually sterile or poorly fertile.

Question 24.
List out the new breeding techniques involved in developing new traits in plant breeding.
Answer:
New Breeding Techniques (NBT) are a collection of methods that could increase and accelerate the development of new traits in plant breeding. These techniques often involve genome editing, to modify DNA at specific locations within the plants to produce new traits in crop plants. The various methods of achieving these changes in traits include the following.

• Cutting and modifying the genome during the repair process by tools like CRISPR /Cas.
• Genome editing to introduce changes in a few base pairs using a technique called Oligonucleotide-directed mutagenesis (ODM).
• Transferring a gene from an identical or closely related species (cisgenesis).
• Organizing processes that alter gene activity without altering the DNA itself (epigenetic methods)

Additional Important Questions and Answers

I. Match the Following

Question 1.

A) a – iv, b – iii, c – ii, d – i
B) a – iv, b – ii, c – iii, d – i
C) a – ii, b – i, c – iv, d – iii
D) a – i, b – iv, c – ii, d – iii
Answer:
A) a – iv, b – iii, c – ii, d – i

Question 2.

A) a – ii, b – iii, c-iv, d-i
B) a – iii, b-ii, c-i, d-iv
c) a – iii, b – i, c-ii, d-iv
D) a – i, b-iv c-iii, d-ii
Answer:
c) a – iii, b – i, c – i, d – iv

Question 3.

A) a – ii, b – iii, c- i, d – iv
B) a – i, b – ii, c – iv, d – iii
c) a – iv, b – i, c – ii, d – iii
D) a – iii, b – iv c – i, d – iv
Answer:
D) a – iii, b – iv c – i, d – iv

Question 4.

A) a – i, b – ii, c – iv, d – iii
B) a – ii, b – iii, c – iv, d – i
c) a – iii, b – iv, c – i, d – iii
D) a – iv, b – i, c – iii, d – ii
Answer:
B) a – ii, b – iii, c – iv, d – i

II. Choose the Odd man Out

Question 1.
a) Rhizoblum
b) Azolla
c) Trichoderma
d) Arbuscular mycorhizae
Answer:
c) Trichoderma

Question 2.
a) Anabaena
b) Amanita
c) Nostoc
d) Azospirillum
Answer:
b) Amanita

Question 3.
a) Natural selection
b) Mass selection
c) Purelinc selection
d) Clonal selection
Answer:
a) Natural selection

Question 4.
a) Cesium
b) Nitromethyl
c) Urea
d) X-ray
Answer:
d) X-ray

III. Choose the incorrect Pair

Question 1.

Answer:
d) South America – Onion

Question 2.

Answer:
C) Dr. K. Ramiah – Wheat breeder

Question 3.

Answer:
a) N2 Fixing Bacteria – Bacillus

Question 4.

Answer:
c) Green Manuring – Sonora – 63

IV. Choose the incorrect Pair

Question 5.

Answer:
b) Blast resistant Rice -1940

Question 6.

Answer:
a) Green Manuring – Tephrosia purpurea

Question 7

Answer:
c) M.S. Swaminathan – TN 1 – hybrid rice

Question 8.

Answer:
d) Cauliflower – Pusa shubhra

V. Assertion and Reason

Question 1.
Assertion : Growing of green manure crops and use of these crops as manure is called Green Manuring.
Reason : It helps to increase the nitrogen in the soil.
a) A & R are true.
b) A & R are Wrong.
c) A is true and R is Wrong.
d) A is wrong and R is true.
Answer:
a) A & R are true.

Question 2.
Assertion : Dr. M.S. Swaminathan is called “Father of green revolution in India.
Reason : He strived hard for conservation of traditional rice varities.
a) Both A & R is True.
b) Both A & R is Wrong.
c) A is True and R is Wrong.
d) A is wrong and R is True.
Answer:
c) A is True and R is Wrong

Question 3.
Assertion(A): A variety formed by pure line selection method shows more homozggosity with respect to all genes.
Reason(R): The pure line plants are produced by asexual method of vegetative propagation method.
a) (A) is correct; (R) is wrong
b) (A) is wrong; (R) is correct
c) (A) is correct; (R) does not explain
d) (A) is correct; (R) explain (A)
Answer:
a) (A) is correct; (R) is wrong

Question 4.
Assertion : Earliest record of Agriculture is found in the fertile Crescent region in and around River Nile
Reason : Approximately 12000, years ago Fertile crescent region is in and around. Tigris and Euphrates river.
a) Both A & R are True.
b) Both A & R are Wrong.
c) A is True and R is Wrong.
d) A is Wrong and R is True.
Answer:
d) A is Wrong and R is True

VI. Choose the Correct Statements

Question 1.
a) Vavilov Studied 247 Cultivated plants
b) Zhukovsky divided the whole world into 12 mega gene centres.
c) Valvilo intially propose 12 main geographic centres of origin
d) Harlan put forward the concept of mega gene centre for the origin of cultivated plants
Answer:
b) Zhukovsky divided the whole world into 12 mega gene centres

Question 2.
a) Foxtail mullet was domesticated by India
b) Wheat & Pea war domesticated by Ethiopia.
c) Castor and Coffee was domesticated by central East
d) Tomato & Pineapple was domesticated by south America
Answer:
d) Tomato & Pineapple was domesticated by south America

Question 3.
a) Seaweeds has more than 70 minerals vitamins and enzymes
b) Trichoderma is a parasitic fungi.
c) Rhizobium is a pathogenic bacteria
d) Azolla is submerged water fern
Answer:
a) Seaweeds has more than 70 minerals vitamins and enzymes

Question 4.
a) Hirngiri is a wheat variety that is resistant to Bacterial blight disease.
b) A Variety of CowPea, Pusakomal is resistent to Hill bunt disease.
c) Pusa shubra is a cauliflower variety that is resistant to Black rot disease
d) Pusa swarnim is a variety of Brassica that is resistent to TMV disease
Answer:
c) Pusa shubra is a cauliflower variety that is resistant to Black disease

VII. Choose the incorrect Statements

Question 1.
a) Mr. Jayaraman was a disciple of Dr. Nammalvar
b) Normal E. Borlaug was awarded Noble prize for peace in 1970.
c) M.S. Swaminathan produced the first semidwarf fertiliser responsive hybrid variety of rice TN 1..
d) Green revolution the term was Coined by Muller
Answer:
d) Green revolution the term was Coined by Muller

Question 2.
The disadvantage of pureline selection is
a) It is difficult to distinguish between hereditary variation from environmental variation.
b) New genotypes are never created so they are less stable to environmental fluctuations
c) The genotype is unchanged for a long period of time.
d) The plants show more heterozygosity.
Answer:
c) The genotype is unchanged for a long period of time.

Question 3.
The possible changes in the plant species due to domestication are
a) Adaptation to a greater diversity of environments.
b) Uniform flowering and fruiting.
c) Drop in Yield
d) Change in breeding system
Answer:
c) Drop in yield

Question 4.
a) Rhizobiurn is best suited for the wheat fields.
b) Azolla that fixes the atmospheric nitrogen along with blue green algae.
c) Arbuscular mycorrhizae also assures water availability
cl) Sea weed liquid fertilizer improves resistance of plants to frost and disease.
Answer:
a) Rhizobium is best suited for the wheat fields

VIII. Choose the correct answer.

Question 1.
The domesticated crop of Mesoamerica is …………………..
a) Tomato
b) Pine apple
c) Sweet Potato
d) Rubber
Answer:
a) Tomato

Question 2.
The domesticated plant of the chiloe centre.
a) Maize
b)Potato
c) Tobacco
d) Olive
Answer:
a) Maize

Question 3.
The domesticated plant of the Near East is______
a) Rye
b) Rice
c) hemp
d) Cotton
Answer:
a) Rye

Question 4.
Name the rice variety with saline tolerance and pest resistance.
a) Wild-type rice
b) Atomita – 2
c) Dwarf rice variety
d) Golden rice
Answer:
b) Atomita -2

Question 5.
Biofertilizers could be also called as …………………
a) Viral inoculants
b) Myco inoculants
c) Protozoan inoculants
d) Bacterial Inoculants
Answer:
d) Bacterial Inoculants

Question 6.
Beauveria species act as a parasite on …………… species.
a) Mammals
b) Aves
c) Arthropod
d) Amphibians
Answer:
c) Arthropod

Question 7.
Damping off of ……………. is caused by Rhizoctonia solani.
a) Tomato
b) Potato
c) Millet
d) Maize
Answer:
a) Tomato

Question 8.
Pongamia pinnata is an important plant species useful for ………………. manure.
a) Organic
b) Potassium rich
c) Green leaf
d) Calcium rich
Answer:
c) Green leaf

Question 9.
Match the following and find the correct answer
(i) Rhizobium – (A) Water ferm
(ii) Trichoderma – (B) Green manuring
(iii) Azolla – (C) Symbiotic bacterium
(iv) Crotolaria – (D) Free living fungus
a) (i) B; (ii) C; (iii) D; (iv) A
b) (i) C; (ii) D; (iii) B; (iv) A
c) (i) C; (ii) D; (iii) A; (iv) B
d) (i) B; (ii) D; (iii) C; (iv) A
Answer:
c) (i) C; (ii) D; (iii) A; (iv) B

Question 10.
More Vigorous hybrid corn was developed in _______
a) 1926
b) 1943
c) 1950
d) 1936
Answer:
a) 1926

Question 11.
In 10,000 BC Domestication of ……………….. was done.
a) Maize
b) Paddy
c) Wheat
d) Sugar cane
Answer:
c) Wheat

Question 12.
The newly introduced plant was carefully examined by the process called …………….
a) PCR Method
b) Dots Method
c) Cisgenesid
d) Quarantine
Answer:
d) Quarantine

Question 13.
National Bureau of plant Genetic Resources is located at ……………….
a) Rangpuri
b) Andhra
c) Pune
d) Bihar
Answer:
a) Rangpuri

Question 14.
Hereditary Variation cannot be distinguished from environmental variation in ………………
a) Pureline selection
b) Clonal Selection
c) Mass Selection
d) Hybridization
Answer:
c) Mass Selection

Question 15.
Johannsen in 1903 coined the word.
a) Clonal Selection
b) Pure line
c) Mass Selection
d) Heterosis
Answer:
b) Pure line

Question 16.
Which one of the following is a biopesticide?
a) Azolla
b) Rhizobium
c) Beauveria
d) Hevea
Answer:
c) Beauveria

Question 17.
…………….. is the best suited measure for maintaining hybrid vigour.
a) Asexual reproduction
b) Vegetative Propagation
c) Grafting
d) Cutting
Answer:
b) Vegetative Propagation

Question 18.
…………. is also termed as luxuriance.
a) Euheterosis
b) Heterosis
c) Mutational heterosis
d) Pseudo heterosis
Answer:
d) Pseudo heterosis

Question 19.
Muller and Stadler coined the term ………………….
a) Mutation Breeding
b) Modern Breeding
c) Plant Breeding
d) Poly ploidy
Answer:
a) Mutation Breeding

Question 20.
Mutation Breeding is the only method of improving …………… crops.
a) Multi seeded
b) single seeded
C) seedless
d) Nutritional
Answer:
c) seedless

Question 21.
Bose Research institute at Calcutta is the first …………. in India.
a) Botanical garden
b) planatorium
c) Zoological park
d) Gamma garden
Answer:
d) Gamma garden

Question 22.
Which one of the following selection method takes longer time in bringing about desired variation?
a) clonal selection
b) Mass selection
c) pureline selection
d) Natural selection
Answer:
d) Natural selection

Question 23.
(A) was originally grown in North India
(B) was orginally grown in South India
a) (A) Saccharum officinarum (B) Saccharum bareri
b) (A) Saccharu bareri (B) Saccharum officinarum
c) (A) Saccharum coarctatum (B) Saccharum alopecuroidum
d) (A) Saccharum alopecuroidum (B) Saccharu coarctatum
Answer:
b) (A) Saccharu bareri (B) Saccharum officinarum

Question 24.
Green revolution is the ………………. Agricultural revolution.
a) Third
b) second
c) third
d) fourth
Answer:
a) Third

Question 25.
…………….. received the national award for best genome saviour. .
a) Nel jeyaraman
b) C.T.Patel
c) Dr.B.P.Pal
d) N.G.P.Rao
Answer:
a) Nel jeyaraman

Question 26.
……………. is the breeding of crops for improved nutritional quality
a) Plant Breeding
b) Heterosis
c) Mutation
d) Biofortification
Answer:
d) Biofortification

Question 27.
High aspartic acid maize leads to resistance to ………………….
a) aphids
b) jassids
c) maize stem borer
d) leaf roller
Answer:
c) maize stem borer

Question 28.
Which one of the following is not a free living N2 fixing organism?
a) Anabaena azollae
b)Azotobacter
c) Clostridium
d) Nostoc
Answer:
c) Clostridium

IX. Fill in the blanks.

1. De candolle in his ……………. studied 247 caltivated plants.
Answer:
Origen of cultivated plants

2. Bamboo eas demesticated by ……………….
Answer:
China

3. He was an eminet Sorghum breeder,devoloped World’s first hybrid of Sorghum CSH-1.
Answer:
N.G.P.Rao.

4. ……………… is used as a biofertilizer for wetland rice cultivation
Answer:
Azolla.

5. Vavilov in the year ………………. converted 8 main geographic centres of origin to 12
Answer:
1935

6. Harlan says that the centre of crop plants means the places of ……………… origin of the crop plants.
Answer:
Agricultural

7. The ……………… was domesticate only in the Chiloe centre
Answer:
Potato

8. ………………. could be also called as Bioinoculants
Answer:
Biofertilizers

9. C.T.Patel devoloped World’s first …………….. hybrid
Answer:
Cotton

10. Choudhary ram dhan made …………….. as punjab granary of India.
Answer:
Wheat

11. Azdla is used as biofertiliser for wetland rice cultivation and is known to contribute ……………./ha/crop.
Answer:
40-60 kg

12. …………….. is Associated with Phycomycetous fungi and angiosperm roots.
Answer:
Arbuscular Mycorhizzoe

13. ……………… contains Auxin,Cytokinin and Gibberellins
Answer:
Seaweed liquid fertiliser

14. ……………… species are free living fungi that are common in soil and root ecosystem
Answer:
Trichoderma

15. Damping of tomato is caused by ……………..
Answer:
Rhizoctonia Solani

16. It is one of the most important green manure crops
Answer:
Tephrosia Purpurea

17. The double helix structure of DNA was identified by ……………. and …………….
Answer:
James Watson,Francis Crick

18. By 2050 we will …………….. need more food to feed the rapid growing population.
Answer:
50%

19. Crop domestication started early during ……………….
Answer:
10,000 Bc

20. ………………. Corn was developed using targetted breeding.
Answer:
Waxy

21. Rice variety of ……………. introduced from Philippines
Answer:
IR8

22. NBPGR is located in Chennai at …………………..
Answer:
Meenembakkan

23. Introduced plants get adapted to the new environment is called as ……………….
Answer:
Acclimatization

24. Tea varieties collected from China and North East India initially grown in Botanical garden of ……………….
Answer:
Kolkatta
Selection

25. ______ is the oldest and basic method of plant breeding
Answer:
Preliminary

26. In clonal selection …………… yield trial takes place during 3rd year.
Answer:
Intrageneric

27. Interspecific hybridization is also called as _____
Answer:
hybridization

28. Green revolution scheme began in ……………. in 1940’s.
Answer:
Mexico

29. In 2005 …………….. organized a first ever traditional paddy seed festival in his farm as an individual.
Answer:
Nel jayaraman

30. …………… is a cleaving protein.
Answer:
Cas9

X. Two Marks

Question 1.
What is Economic Botany?
Answer:
It is the study of the relationship between people and economically important plants.

Question 2.
When did people started practising Agriculture?
Answer:

• Archeological evidence for earliest record of agriculture is found in the fertile crescent region in and around Tigris and Euphrates river valleys, approximate about 12,000 years
  ago

Question 3.
What was the contribution by De Candolle towards agriculture?
Answer:

• He studied 247 cultivated plant species.
• He attempted to solve the mystery about the anscestral form, region of domestication and history.

Question 4.
How many geographic centres were proposed by vavilov?
Answer:

• Initially he proposed eight main geographic centres of origin.
• Later by dividing few centres into two or three centres and added a new centre USA.
• Thus making the 8 centres of Origin into 12.

Question 5.
Define Biofertilizers.
Answer:

• It is defined as preparations containing living cells of efficient strains of micro organisms that help in crop yield.

Question 6.
What is component of seaweed liquid fertilizer?
Answer:

• It contains Cytokinin, Gibberellins, and auxin a part from macro & micro nutrients.
• It has Alginates, Carbohydrate, 70 types of minerals, Vitaming and enzymes.

Question 7.
Trichoderma has been recognised as bio¬control agent – Give Reasons.
Answer:

• It control plant diseases
• Ability to enhance root growth.
• Increases crop productivity.
• Provides resistance to abiotic stress.
• Helps in uptake and use of nutrients.

Question 8.
What is plant introduction?
Answer:

• Introduction of genotypes from a place where it is normally grown to a new place.
• eg. IR & Rice from Philippines.

Question 9.
Define Acclimatization?
Answer:

• The adjustment or adaptation of the introduced plant in the changed environment is called acclimatization.

Question 10.
What is Quarantine?
Answer:

• All the introduced Crop must be free from presence of weeds, insects and disease causing Organisms.
• It has to be carefully examined by the process called quarantine.
• A strict isolation imposed to prevent the spread of disease.

Question 11.
What is Natural Selection?
Answer:

• This is a rule in the nature.
• It results in evolution reflected in the Darwinian’s principle survival of the fittest.
• It takes longer time to bring about desired Variation.

Question 12.
What is Arificial Selection?
Answer:

• It is a human involved process.
• Having better crop from a mixed population.
• The individuals differ in character.

Question 13.
Name the three types of Artificial Selection.
Answer:
a) Mass Selection,
b) Pureline Selection,
c) Clonal Selection

Question 14.
What is Emasculation
Answer:

• It is a process of removal of anthers to prevent self pollination before the opening of a flower.

Question 15.
What are the various types of Mutagens?
Answer:

• Physical Mutagen – UV short wave, X-ray, Alpha, Beta and Gamma Waves.
• Chemical Mutagen – Cesium, Ethylmethane sulfonate Nitromethyl and Urea.

Question 16.
What is Gamma Garden?
Answer:

• It is a form of mutation breeding.
• The Radioactive sources are cobalt – 60 and Caesium -137
• The first Gamma Garden in India is Bose Research institute at Calcutta.

Question 17.
What are the benefits of polyploidy?
Answer:

• It often exhibit increase hybrid vigour.
• Increase the tolerance to both biotic and abiotic stresses

Question 18.
How Polyploidy can be induced? List out the products achieved through polyploidy.
Answer:

• Polyploidy can be induced by the use of cochicine to double the chromosome number.
• Seedless Tomato, Apple, Watermelon and orange.

Question 19.
Define Green Revolution.
Answer:

• It is the cumulative result of a series of research, development, innovation and technology transfer initiatives in Agriculture.

Question 20.
Write about the contribution of Dr. M.S.Swaminathan in mutation breeding.
Answer:

• He is the pioneer mutation breeder.
• He has produce sharbati Sonora is the amber grain coloured variety of wheat.
• He is responsible for green revolution in India.

Question 21.
What are the objectives considered in Breeding to improve the nutritional quality of plants?
Answer:
To improve protein, oil, vitamin, Micronutrient and mineral content and quality

Question 22.
Tabulate certain crops and the pest resistant Variety?
Answer:

Question 23.
Expand the following.
Answer:

• CRISPR – Clustered Regularly Interspaced short Palindromic Repeats
• ODM – Oligonucleotide – Directed Mutagenesis.

Question 24.
Which method of artificial vegetative reproduction is good in plants. Give reason for your answer.
Answer:
Tissue culture is the modern artifical reproductive technique.

Reasons:

•  large scale production of clones (genitically uniform population) from the callus tissue – developed from the chosen explant cells (invitro)
• Both crop and tree species useful in forestry can be produced with desirable characters in large numbers with in a short span of time.

Question 25.
What are the advantages of rice field?
Answer:

• Azolla is a free floating water fern that fixes atmospheric nitrogen in association with nitrogen fixing blue green algae. Anabaena azolla.
• It is used as a bio-fertilizer for wetland rice cultivation and is known to contribute 40-60 kh/hal/crop.

Question 26.
Write the any three names of plant species useful in green manure?
Answer:

• Cassia fistula
• Sesbania grandiflora
• Azadirachta indica

Question 27.
What is Bio-pesticides with example
Answer:
Bio-pesticides are biologically based agents used for the control of plant pests.
Example: Trichoderma.

XI. Differentiate Type Questions

Question 1.
Differentiate Biofertilizers and Green manuring
Answer:

Question 2.
Differentiate Pureline selection and clonal selection
Answer:

Question 3.
Differentiate Mutation Breeding and Polyploid Breeding
Answer:

Question 4.
Differentiate Intervarietal and Interspecific Hybridization.
Answer:

XII. Three marks

Question 1.
What are the fields involved in Economic Botany?
Answer:

• Agronomy, Anthropology, Archaeology, Chemistry, trade and commerce.

Question 2.
Define Domestication.
Answer:

• It is the process of bringing a plant species under the control of humans and gradually changing it through careful selection.

Question 3.
What is Organic Agriculture?
Answer:

• It is as alternative agricultural system.
• It is due to rapidly changing farming practices.
• It is a production system that sustains the health of the soils, ecosystems and people.
• It is based on ecological processes biodiversity and cycles adapted to local conditions

Question 4.
Write about the role played by Beauveria as a Bio-pesticide
Answer:

• It is an entomo-pathogenic fungi
• It acts as a parasite on various arthropod that causes white muscardine disease.
• It also controls datnping off of tomato caused by Rhizoctonia Solani.

Question 5.
Differentiate Green manuring and Green leaf manuring.
Green Manuring

• Growing of green manure crops and use these crops directly in the field by ploughing.
• It increases the nitrogen in the soil.
• It helps to improve the physical property of the soil.
  eg. Crotalaria juncea.

Green Leaf Manuring

• Application of green leaves twigs, shrubs, plants growing in wasteland and field bunds.
• The important plant species useful for green leaf manure are – cassia fistula. Delonix regia.

Question 6.
Define plant breeding
Answer:

• Plant breeding is the science of improvement of crop varities with higher yield better quality, resistance to diseases and shorter durations which are suitable to particular environment.

Question 7.
What is the plan of thrid Agricultural Revolution
Answer:
The Green revolution or thrid Agricultural Revolution is the intensive plan of 1960’s to increase crop yield in developing countries by introducing the high yielding, resistant varieties, increased irrigation facilities, fertilizer application and better agricultural management.

Question 8.
Draw a flow chart showing the steps involved in plant Breeding.
Answer:
The main steps in plant breeding are given below

Question 9.
Write about NBPG R
Answer:

• It is responsible for introduction and maintence of germplasm of various agricultural and horticultural station in our country.
• It is also responsible for maintenance of plant materials of botanical and medicinal interest.
• It is located at Rangpuri/New Delhi with four regional station at Amristar, Kolkata, Mumbai and Chennai.

Question 10.
Draw the Schematic difference between Mass & Pureline selection.
Answer:

Question 11.
What is hybridization?
Answer:

• Hybridization is the method of producing new crop verities by crossing of plants that are genetically different.
• It offers improvement in crop by combining the desirable character of two or more varities.
• The first natural hybridization was observed by Cotton Mather in maize.

Question 12.
A type of Heterosis is called as Pseudoheterosis – Why?
Answer:

• It is called as pseudoheterosis because the progeny is superior over parents by vegetative growth.
• They are usually sterile.
• It is also called as Luxuriance.

Question 13.
Tabulate certain crop variety and the disease to which they are resistant.
Answer:

Question 14.
What is Norm 10?

• It is dwarfing genes with high photosynthetic rate and increases the respiratory activity.
• Gonjiro Inazuka was scientist, who selected the Semi- dwarf wheat variety – Norm 1o.
• This variety helped one billion lives from hunger and starvation.

Question 15.
How can we develop resistance to Insect pests in plants?

• Insect resistance in host crop plants may be due to morphological, biochemical 0r physiological characteristics.
• Hairy leaves in plants – Jassids in cotton
  – Cereal leaf bettle in wheat.
• Solids Stem – Stem sawfly.
  Smooth leaves and nectar less cotton – Bol worms.
  High aspartic acid, low nitrogen and sugar content – Maize stem borers.

Question 16.
What are the plant breeding tools used to improve the crop varieties?
Answer:

• Genetic Engineering, plant tissue culture, protoplasmic fusion, Molecular marking and DNA finger printing.

Question 17.
Define mutation breeding?
Answer:
Mutation means the sudden heritable changes in the genotype or phenotype of an organism.

Question 18.
What is Bio-fortification?
Answer:
Breeding crops with higher levels of vitamins and minerals or higher protein and healthier fats is the most practical means to improve public health.

Question 19.
Comment on sugercane.
Answer:

• Saccharum bareri was originally grown in north India.
• It is poor sugar content and yield.
• Tropical canes grown in south India saccharurn officinarum had thicker stems and higher sugar content.
• It did not grow well in North India
• These two species were successfully crossed to get sugar cane varieties combining the desirable qualities of high yield thick stems high sugar and ability to grows in the sugar cane areas of North India.

XIII. Five Marks

Question 1.
What are the possible changes in the plant due to domestication?
Answer:

• Adaption to the environmental alteration.
• Adaption to wider geographical range.
• Uniformity in flowering and fruiting.
• Increased size of fruits and seeds.
• Change in breeding system.
• Increase in yield.
• Increased resistance for disease and pest.
• Developing seedless parthenocarpic fruit.
• Enhancing the taste and nutritional composition.

Question 2.
Enumerate the History of Agriculture:
Answer:

• 1807 – Alexander Yon Humboldt considered that original & source of most and their origin is an importable secret.
• 1868 – Darwin’s theory proposed that natural selection and hybridization led to the origin of cultivate plants.
• 1883 – De Candolle studied 247 cultivated plants species and was able to find the ancestral form, region of domestication and history.
• 1887-1943 – Vavilov studied about the diverse forms of plants based on various criteria like morphology,cytology etc., He proposed 8 geographic centres and later developed it to 12 centres.
• 1968 – Zhukovsky put forward the concept of mega gene and divided the whole world into 12 mega gene centres.
• 1971 – Harlen believed that agriculture originated independently in three different areas.
  – There were non centres are the area were the crop has been shifted.

Question 3.
Tabulate the vavilov’s centres of crop origin and crop domesticated.
Answer:
Vavilov’s centres of crop origin and crops domesticated.

Question 4.
Write an essay on Indian plant Breeders.
Answer:

• Dr.M.S.Swaminathan- He is pioneer in mutation breeder.
• Sir.T.S.Venkatraman- An eminent sugarcane breeder.
• Dr.B.P.Pal-Developed superior disease resistant varieties of wheat
• Dr.K.Ramiah- Eminent Rice Breeder.
  N.G.P.Rao-An eminent sorghum breeder, developed world’s first hybrid of sorghum (CSH-1).
• C.T.Patel-Developed world’s first cotton hybrid.
• Choudhary Ram Dhan – wheat breeder,developed C-591 wheat which made Punjab as wheat granary of india.

Question 5.
Differentiate Rhizobium from Azolla as bio-fertilizers.
Answer:

• Bio-fertilizers could also be called as microbial cultures or bacteria) fertilizers.
• They are efficient in fixing nitrogen improve soil fertility, eco-friendly and cost effective.

Rhizobium:

• It resides in the root nodules of leguminous plants.
• It fixes the atmospheric Nitrogen.
• It increases yield of paddy by 15-40%

Azolla:

• Free floating water fern, with blue green algae fixes the Nitrogrn.
• It increases the yield of rice.
• It decomposes quickly.

Arbuscular Mycorrhizae:

• They can dissolve the phosphates found in the soil.
• It provides strength to resist disease, germ and unfavourable weather.

Seaweed Liquid Fertilizer:

• It contains cytokinin, gibberellins and Auxin
• Most of it are made from kelp ( Brown Algae).
• The alginates in it react with metals in soil and retain moisture for a long time.
• They have more than 70 minerals vitamin and enzymes.
• Seeds soaked in seaweed germinate rapidly.

Question 6.
Tabulate the classification of Biofertilizers.
Answer:

Question 7.
Discuss about Biopesticides in detail.
Answer:

• They are biologically based agents used for the control of plant pests.
• They are ecofriendly , Non – toxic and cheaper the chemical pesticide.

Trichoderma:

• They are free living fungi in the soil.
• They control plant disease.
• It has the ability to enhance root growth development.
• Increases the crop productivity.
• It helps in resisting Abiotic stress.
• It increases the uptake and use of nutrients.

Beauveria:

• It is an entomo – pathogenic fungus
• It parasitse arthropods that cause white muscardine and controls damping off of tomato

Question 8.
Enumerate the objectives of plant Breeding.
Answer:

• To increase yield, Vigour and fertility of the crop.
• To increase tolerance to environmental condition, Salinity, Temperature and drought.
• To prevent premature falling of buds fruits etc.,
• To improve the maturation of both the male and female gametes at the same time.
• To develop resistance to pathogens and pests.
• To develop photosensitive and thermos – Sensitive Varieties.

Question 9.
Discuss about the types of selection.
Answer:

• Selection is the oldest and basic method of plant breeding.
• There are two main types of selection – Natural and Artificial.

Natural Selection:

• It occurs naturally.
• It takes longer time in bringing about desired variation.
• It reflected the Darwinian principle.

Artificial Selection:

• It is a human involved process.
• Producing better crop from a mixed population.

a) Mass Selection :

• Large number of plants of similar phenotype are selected and crossed to get a new variety.
• After repeated selection for five to six years it is distributed to the farmers.

b) Pureline Selection:

• Plants obtained as a result of self pollination from a single homozygous individual.
• The progeny shows homozy gosity with respect to all genes.
• New Genotypes are never created,

c) Clonal Seection:

• The progenies that are asexually propagated resembles the parent genetically.
• The progeny is multiplied to form clone.
• The genotype of a clone remains unchanged for a long period of time.

Question 10.
Describe the steps involved in Hybri-dization.
Answer:
a) Selection of Parents :

• Male and female plants of desired characters are selected.
• It should be tested for their homozygosity

b) Emasculation:

• It is removal of anther before blooming.
• It avoids self pollination

c) Bagging:
The stigma is protected against any undesirable pollen grains, by covering with a bag.

d) Crossing:
Transfer of pollen grains from selected male flower to the stigma of the emasculated female flower.

e) Harvesting Seeds and Raising Plants :

• Due to fertilization seeds form.
• These seeds are grown into a new generation.

Question 11.
Discuss about the types of heterosis.
Answer:
a) Euheterosis:

• It is the true heterosis.
• It is inherited

b) Mutational Euheterosis :

• It is the simplest form.
• Removal of harmful, recessive, mutant genes by superior dominant allele in cross pollinated crops.

c) Balanced Euheterosis:

• Well balanced gene combination.
• More adaptive to environment and agricultural usefulness.

d) Psuedo heterosis :

• Also known as luxuriance.
• Progeny possess superiority over parents in regetative Growth.
• But not in yield & adaptation.
• Usually sterile or poorly fertile.

Question 12.
Describe polyploid Breeding.
Answer:

• The plants which posses more than two sets of chromosomes are called Polyploids.
• It is the major force in the evolution of both wild and cultivated plants.
• Polyploid of exhibit hybrid vigour.
• Increases tolerance to biotic and abiotic stresses.
• Polyploidy results in reduced fertility and producing seedless varieties.
• If chromosomes is doubled by itself it is autopolyploidy.
• Triploid condition in Sugarbeets result in Vigour.
• Colchicine used to double the chromosomes. Eg. Triticale and Raphanobrassica

Question 13,
Biofortification is the breeding crops with
higher levels of nutrients. Justify it..
Answer:
Breeding of improved nutritional quality like
– Protein content and quality.
– Oil content and quality
– Vitamin Content
– Micro & Macro nutrient content.

• In 2000 – Maize hybrid had twice the nutrient value than the parents.
• Wheat – Atlass 66 having high protein content.
• Iron fortified rice can be developed.
• Vitamin A enriched vegetable.
• Vitamin C enriched vegetables and iron and calcium crops also developed.

Question 14.
Enumerate the New Breeding Techniques.
Answer:

• It is a collection of methods that could increase the development of new traits in plant breeding.
• It often involve genome editing.
• Cutting and modifying the genome during the repair process by tools like CRISPR.
• Genome editing to introduce changes in few base pairs using a technique called ODM.
• Transferring a gene from an identical or closely related species (Cisgenesis)
• Organising process that alter gene activity without altering the DNA itself.

Question 15.
Ramu and Somu are farmers. Ramu cultivated the crops by self fertilization method. Somu cultivated the crops from mixed population.
(i) Who will get new variety?
(ii) Write the advantage and disadvantages of their selection.
Answer:
(i) Somu will get the new variety. Because he had selected the mixed population method.

(ii) Advantages of self fertilization method:
The repeated self pollination from a single homozygous individual produces a variety that shows more homozygosity with respect to all genes.

(iii) Dis advantages:

• The major disadvantage of this type is that it never creates new genotypes.
• The plants produced are also less adaptible and less stable to the environmental fluctuations.

Advantages of Mixed population method
In this method, a large number of plants of similar phenotype (or) morphological characters are selected and their seeds are mixed together to constitute a newer variety’.

Disadvantages:
The disadvantage of mixed population method is that it is difficult to distinguish the hereditary variation from environmental variation .

Question 16.
Mention the benefits of seed treatment?
Answer:

• Prevents spread of plant disease
• Protects seed from seedling blights
• Improves germination
• Improves germination
• provides protection from storage insects
• controls soil insects.