CBSE Class 12 Biology Strategies for Enhancement in Food Production Assignment Set 01

Question. A biofortified wheat variety is
(a) Altas 66
(b) IR-8
(c) Kalyan Sona
(d) Sonalika
Answer : A

Apiculture : Rearing of honeybees for the production of honey, beewax, royal jelly and bee Venom.

Artificial insemination : Introduction of semen of good quality of male into the vagina of female.

Explant : A part of plant excised from its original location and used for tissue culture.

Germplasm Collection : The entire collection having all the diverse alleles for all the genes in the given organism.

Inbreeding depression : Continued close inbreeding decreases the fertility and productivity.

Inbreeding : Inbreeding refers to the mating of more closely related individuals within the same breed for 4-6 generations.

Out-breeding : Out-breeding is the breeding of the unrelated animals, which may be between individuals of the same breed (but having no common ancestors), or between different breeds (cross breeding or different species (interspecific hybridisation).

Super Ovulation : Stimulation of good female animal by administering hormones to produce more eggs.

Mutation breeding : Mutation in plants in induced artificially through use of mutagens to obtain desirable characters. These plants (as a source) are used in breeding.

Totipotency : The ability to generate a whole plant from any cell/explant.

Strategies for Enhancement in Food Production

Points to Remember

• Apiculture: The commercial rearing and maintenance of honeybee hives for harvesting honey, beeswax, royal jelly, and bee venom.
• Artificial Insemination: The controlled introduction of semen collected from a superior male into the reproductive tract of a selected female animal.
• Explant: Any excised plant tissue or organ taken from its original position and utilized to initiate an in vitro tissue culture.
• Germplasm Collection: The comprehensive assembly and preservation of all diverse alleles for all the genes present in a particular crop species and its wild relatives.
• Inbreeding Depression: The reduction in biological fitness, fertility, and overall productivity that occurs due to continuous, close inbreeding over multiple generations.
• Inbreeding: The controlled mating of closely related individuals belonging to the same breed for 4 to 6 generations.
• Out-breeding: The breeding of unrelated animals, which includes mating individuals of the same breed lacking common ancestors (outcrossing), pairing animals from distinct breeds (cross-breeding), or crossing different species (interspecific hybridization).
• Superovulation: The hormonal induction of a genetically superior female animal to produce multiple mature ova (6 to 8 eggs) per estrous cycle.
• Mutation Breeding: The process of inducing genetic alterations in plants using physical or chemical mutagens to develop desirable traits, which are subsequently integrated into breeding programs.
• Totipotency: The inherent biological capacity of an isolated plant cell or explant to regenerate into an entire plant.

Abbreviations

• ET: Embryo Transfer
• IARI: Indian Agricultural Research Institute
• IRRI: International Rice Research Institute
• ICAR: Indian Council of Agricultural Research
• MOET: Multiple Ovulation Embryo Transfer
• NDRI: National Dairy Research Institute

Summary of Key Concepts

• Animal Husbandry: The agricultural discipline dedicated to the care, breeding, and management of livestock beneficial to humans.
• Poultry Farm Management: The commercial rearing of domesticated fowl, predominantly chickens and ducks, and occasionally turkeys and geese, for meat and eggs.
• Bee-keeping (Apiculture): Maintenance of honeybee colonies, commonly using Apis indica in India, to collect high-energy nutritive honey and commercial beeswax.
• Fisheries Management:
  • Freshwater fishes: Catla, Rohu, common carp.
  • Marine fishes: Hilsa, Sardines, Mackerel, Pomfret.
• Aquaculture vs. Pisciculture: Aquaculture encompasses the farming and commercial production of all useful aquatic flora and fauna (such as prawns, lobsters, edible oysters, and crabs), whereas pisciculture refers specifically to the farming of finfishes.
• Blue Revolution: The initiative aimed at rapidly escalating the production and harvest of fish and other aquatic resources.
• Outcrossing: Mating animals within the identical breed that share no common pedigree ancestors for 4 to 6 generations; a single outcross effectively overcomes inbreeding depression.
• Cross-breeding: Mating superior males of one specific breed with superior females of a different breed to combine favorable traits from both lines.

Main Steps in Breeding a New Genetic Variety of Crop

• (i) Collection of variability (germplasm collection).
• (ii) Evaluation and selection of prospective parents.
• (iii) Cross-hybridization between selected parent lines.
• (iv) Selection and testing of superior recombinants.
• (v) Testing, release, and commercial distribution of new cultivars.

High-Yielding Crop Cultivars

• Wheat: Sonalika, Kalyan Sona.
• Rice: IR-8, Taichung Native-1, Jaya, Ratna, Padma.
• Sugarcane: High-sugar, thick-stemmed hybrids developed by crossing South Indian Saccharum officinarum with North Indian Saccharum barberi.

Common Plant Diseases

• Viral: Tobacco mosaic, turnip mosaic.
• Bacterial: Black rot of crucifers, blight of rice.
• Fungal: Brown rust of wheat, red rot of sugarcane, late blight of potato, smut of wheat.

Flowcharts and Methodologies

1. Animal Husbandry Classifications:

• Dairy Farming (Milk production)
• Poultry (Eggs and meat)
• Fisheries (Fish and aquatic species)
• Piggery (Pork production)
• Aviaries (Rearing birds)

2. Animal Breeding Strategies:

• Inbreeding: Mating closely related animals within the same breed for 4 to 6 generations to increase homozygosity.
• Outbreeding:
  • Outcrossing: Unrelated animals of the same breed without common ancestors for 4 to 6 generations.
  • Cross-breeding: Superior males of one breed mated with superior females of another breed (e.g., Hisardale sheep).
  • Interspecific Hybridization: Crossing two different related species (e.g., Mule).
• Controlled Breeding Techniques:
  • Artificial Insemination: Semen collected from an elite male is stored, transported, and injected into the female reproductive tract.
  • MOET (Multiple Ovulation Embryo Transfer): Superovulation via FSH hormone followed by non-surgical recovery of 8 to 32 celled embryos and transfer to surrogate dams.

3. Somatic Hybridization Pathway:

Plant Cells (Tomato and Potato) → Cell wall digestion by Cellulase and Pectinase → Isolated naked protoplasts → Induced protoplast fusion via Polyethylene Glycol (PEG) or electric pulses → Somatic hybrid cell (Pomato) → Cell wall regeneration and division → Somatic hybrid plantlets.

Questions

VSA (1 Mark)

Question 1. Why is inbreeding necessary in animal husbandary?
Answer: Controlled inbreeding is crucial because it promotes homozygosity, allowing animal breeders to isolate and preserve purelines. Furthermore, it helps reveal harmful recessive alleles so they can be eliminated while simultaneously accumulating and fixing desirable traits in the herd.
In simple words: Inbreeding makes genes uniform, bringing out superior traits and filtering out unwanted ones.

Exam Tip: Highlighting the term "increases homozygosity" is vital to securing the full mark in this question.

Question 2. Name two fungal diseases of Crop plants.
Answer: Two well-known fungal infections in agricultural crops include brown rust of wheat and red rot of sugarcane (additional examples include smut of wheat and late blight of potato).
In simple words: Fungi cause diseases such as sugarcane red rot and wheat rust.

Exam Tip: Always pair the pathogen symptom with its host plant, for example "brown rust of wheat" instead of merely writing "rust".

Question 3. Which product of Apiculture is used in cosmetics and polishes?
Answer: Beeswax, secreted by worker honeybees, serves as an essential base material in the cosmetic industry and for manufacturing commercial polishes.
In simple words: Beeswax is the hive product used to produce skin creams, lipsticks, and polishes.

Exam Tip: Do not mention honey here; beeswax is the primary apiculture byproduct utilized in industrial and cosmetic preparations.

Question 4. Semi-dwarf varieties of a crop plant were derived from IR-8. Name that crop.
Answer: The crop is rice (paddy), whose semi-dwarf strains were bred using germplasm derived from the International Rice Research Institute's IR-8 line.
In simple words: The crop is rice (paddy).

Exam Tip: Either "paddy" or "rice" is acceptable, but writing "rice (paddy)" prevents ambiguity.

Question 5. Write two qualities of Saccharum officinarum (Sugarcane) grown in South India.
Answer: The tropical sugarcane species Saccharum officinarum features robust, thicker stalks and contains a significantly higher percentage of sucrose.
In simple words: It has thick stems and provides a very high sugar content.

Exam Tip: Be ready to compare this species with North Indian Saccharum barberi, which has thin canes and poor sugar yield.

SA-II (2 Marks)

Question 6. A new breed of sheep was developed in Punjab by crossing two different breeds of Sheep. Name the two breeds which were crossed and the new breed developed.
Answer: The synthetic sheep variety produced in Punjab is Hisardale. It was developed through cross-breeding between Bikaneri ewes (female sheep) and Merino rams (male sheep).
In simple words: Mating female Bikaneri sheep with male Merino sheep created the Hisardale breed.

Exam Tip: Specify which parent breed was the ewe (female: Bikaneri) and which was the ram (male: Merino) to ensure full marks.

Question 7. Study the table given below and fill in the blanks marked A, B, C and D
 

Answer:
(A) Leaf and stripe rust, hill bunt
(B) Pusa Swarnim (Karan rai)
(C) Cowpea
(D) Pusa Sadabahar
In simple words: Himgiri resists rusts and bunt, Pusa Swarnim resists white rust, Pusa Komal is cowpea, and Pusa Sadabahar is the virus-resistant chilli.

Exam Tip: Questions based on the NCERT plant breeding table frequently appear in CBSE board papers; memorize all crop varieties and their targeted pathogens.

Question 8. Why are proteins synthesized from Spirulina called Single celled Proteins? What is the significance of such a protein?
Answer: Spirulina is a unicellular photosynthetic cyanobacterium, so edible biomass derived from such microscopic single-celled organisms is termed Single Cell Protein (SCP).
Significance:
(i) Rapid biomass multiplication provides a rich source of proteins, minerals, and vitamins that can bridge the human and animal nutritional gap.
(ii) Because it can be cultivated on waste effluents (such as potato processing wastewater, straw, and molasses), it curbs environmental pollution while producing affordable food.
In simple words: It comes from a single-celled microbe, grows very fast, and gives a nutrient-rich protein meal while cutting down on waste.

Exam Tip: Mention both nutritional value (rich protein substitute) and ecological benefit (utilizes industrial effluent as growth medium).

Question 9. Differentiate between inbreeding and outbreeding in animals.
Answer:
 

In simple words: Inbreeding pairs close relatives of the same breed, whereas outbreeding mates animals that are unrelated, from different breeds, or from different species.

Exam Tip: A tabular comparison displaying definitions and genetic consequences (homozygosity vs. heterozygosity) earns full marks.

Question 10. Observe the process of Somatic hybridisation given below and fill in the blanks. (i), (ii), (iii) and (iv)
Answer:
(i) Isolated protoplasts of tomato and potato cells
(ii) Somatic hybridization (protoplast fusion)
(iii) Pomato
(iv) Somatic hybrid
In simple words: Removing the walls yields naked protoplasts; fusing them together produces a somatic hybrid called pomato.

Exam Tip: Be familiar with the chemical agent used in step (ii) - Polyethylene Glycol (PEG) - as it is frequently asked in related objective questions.

SA I (3 Marks)

Question 11. What is micropropagation? Why are plants produced by this technique called somaclones? Name any two food plants which are produced on commercial scale using this method.
Answer:
- Micropropagation is the in vitro tissue culture method used to regenerate hundreds to thousands of complete plantlets rapidly from small explants maintained under aseptic conditions.
- The plants regenerated are termed somaclones because they develop from vegetative (somatic) tissue via mitotic divisions, making each plantlet an exact genetic replica of the original parent plant.
- Commercial food plants produced using this technique include banana, tomato, and apple.
In simple words: Micropropagation clones thousands of identical plants from small tissue samples in test tubes. They are called somaclones because their DNA matches the parent plant.

Exam Tip: Ensure you clearly explain both aspects: the tissue culture technique itself and the genetic identity behind the term "somaclones".

Question 12. What is mutation? Explain the significance of mutation in plant breeding. Give an example of a disease resistant variety of cultivated plant induced by mutation.
Answer:
- Mutation is an abrupt, heritable modification in an organism's genomic base sequence that generates unique characters absent in the parental generation.
- Significance in plant breeding: Natural genetic variability is often limited; exposing seeds or plant tissues to mutagens (such as gamma rays) induces novel alleles. Breeders evaluate these mutants to identify desirable agronomic characters, such as pathogen resistance, and integrate them into commercial cultivars.
- Example: In mung bean (Vigna radiata), mutation breeding successfully introduced resistance against yellow mosaic virus and powdery mildew.
In simple words: A mutation is a sudden genetic change. Plant scientists trigger helpful mutations with radiation, such as virus resistance in mung beans.

Exam Tip: Naming gamma rays as the physical mutagen and specifying resistance to yellow mosaic virus in mung bean are crucial keywords for full marks.

Question 13. How can we improve the success rate of fertilisation during artificial insemination in aminal husbandary programmes?
Answer:
Fertilization and breeding efficiency are significantly upgraded using Multiple Ovulation Embryo Transfer (MOET) technology:
(i) A donor cow receives hormonal therapy with Follicle Stimulating Hormone (FSH) activity to induce follicular maturation and superovulation, yielding 6 to 8 ova instead of the usual single egg per cycle.
(ii) The female is mated with a pedigreed bull or artificially inseminated using semen of superior quality.
(iii) Fertilized embryos are harvested non-surgically when they reach the 8 to 32 celled stage.
(iv) Each embryo is subsequently transferred to an individual surrogate mother, freeing the genetic mother for another cycle of superovulation.
In simple words: Hormones trigger a cow to make multiple eggs, which are fertilized and implanted into surrogate mothers to multiply elite calves quickly.

Exam Tip: Remember to state the stage of non-surgical recovery: embryos at the 8 to 32 celled stage.

Question 14. Biofortification is the most practical means to improve public health. Justify the statement with examples.
Answer:
Biofortification refers to developing crops containing higher concentrations of vitamins, minerals, proteins, and healthier lipids. It provides an economical, sustainable way to eliminate micronutrient malnutrition ("hidden hunger") in underprivileged populations who cannot afford diverse diets.
Examples supporting this approach:
(i) Maize hybrids developed in 2000 possessed twice the levels of essential amino acids, particularly lysine and tryptophan, compared to traditional varieties.
(ii) The wheat cultivar Atlas 66, recognized for high protein content, has been utilized as a donor line to enrich cultivated wheat.
(iii) Iron-fortified rice varieties have been bred that deliver over five times the iron concentration of common rice.
(iv) IARI has released fortified vegetables like vitamin A-rich spinach and carrots, plus vitamin C-enriched bitter gourd.
In simple words: Biofortification breeds crops packed with extra nutrients and vitamins to combat hidden hunger and improve daily diets affordably.

Exam Tip: Always mention the term "hidden hunger" and cite specific examples like lysine-rich maize or Atlas 66 wheat.

Question 15. What is meant by germplasm Collection? Describe its significance in plant breeding programmes.
Answer:
- Germplasm collection is the complete repository of seeds, plants, and tissue cultures preserving all diverse alleles for all genes found in a crop species and its wild relatives.
- Significance in plant breeding:
(i) It forms the foundational prerequisite of every crop improvement program, providing raw genetic variation.
(ii) Researchers screen the collection to discover valuable traits such as resistance to environmental stresses, pests, and disease pathogens.
(iii) Identified alleles can be selectively transferred into modern high-yielding varieties through systematic hybridization.
In simple words: Germplasm collection stores all available gene variations of a plant, giving scientists the traits needed to breed stronger crops.

Exam Tip: Emphasize that the collection includes both cultivated varieties and wild relatives to capture the broadest genetic base.

Question 16. To which product, following products are related (a) Blue revolution (b) white revolution (c) Green revolution
Answer:
(a) Blue revolution - Fish and other aquatic animal production (aquaculture and pisciculture)
(b) White revolution - Dairy and milk production (Operation Flood)
(c) Green revolution - Agricultural food grains and cereal crop production (primarily wheat and rice)
In simple words: Blue represents fish farming, White represents milk production, and Green represents cereal crops.

Exam Tip: Keep the response concise and clearly identify the specific commodity associated with each revolution.

LA (5 Marks)

Question 17. Does apiculture offer multiple advantages to farmers? List its advantages, if it is located near a place of commercial flower cultivation. Name the most common species of bee which is reared in India.
Answer:
Yes, apiculture (bee-keeping) provides substantial agronomic and economic benefits to farmers with relatively low capital investment.
Advantages of placing apiaries adjacent to commercial flowering fields:
(i) Enhanced cross-pollination: Honeybees serve as principal pollinators for numerous cultivated species, including sunflower, mustard, apple, and pear. Their foraging activity increases pollination efficiency, boosting seed set and overall crop yield.
(ii) Increased honey and wax output: Proximity to floral crops ensures bees have access to abundant nectar and pollen reserves, markedly raising the total honey harvest without supplemental feeding.
(iii) Diversified farm revenue: Farmers harvest valuable commercial products such as honey, royal jelly, and beeswax, which is widely utilized in candle-making, polishes, and the pharmaceutical/cosmetic trade.
The most prevalent domesticated honeybee species reared in India is Apis indica.
In simple words: Yes, placing bee hives near flowering fields improves pollination to boost crop yields, while also giving the farmer a higher harvest of honey and beeswax. The common Indian bee is Apis indica.

Exam Tip: Emphasize the reciprocal benefit: bees assist crop yield via pollination, while floral nectar enhances honey production.

Question 18. What is somatic hybridisation? Describe the various steps in producing somatic hybrids from protoplasts. Mention any two uses of somatic hybridisation.
Answer:
- Somatic hybridization is the in vitro biotechnology technique of isolating and fusing naked protoplasts from somatic cells of two distinct plant varieties or species to generate a hybrid plant.
- Procedural steps involved:
1. Isolation of protoplasts: Intact cell walls of selected plant leaves or calli are enzymatically dissolved using a combination of pectinase and cellulase, releasing naked protoplasts bounded solely by cell membranes.
2. Protoplast fusion: The isolated protoplasts from both parents are incubated together and stimulated to fuse using chemical fusogens like Polyethylene Glycol (PEG) or through electrical field pulses.
3. Cell wall regeneration: The hybrid protoplasts are grown in an appropriate sterile nutrient medium where they synthesize a replacement cellulosic cell wall.
4. Callus formation and plantlet differentiation: Fused hybrid cells undergo mitotic divisions to develop a callus, which subsequently differentiates into somatic hybrid plantlets (e.g., "pomato" derived from tomato and potato).
- Uses of somatic hybridization:
(i) Allows hybridization between sexually incompatible species where normal sexual reproduction fails due to pre- or post-zygotic barriers.
(ii) Facilitates the transfer of beneficial cytoplasmic traits (such as male sterility or herbicide tolerance) by combining diverse organelle genomes.
In simple words: Somatic hybridization strips plant cell walls with enzymes, fuses the bare cells using PEG, and regenerates a new hybrid plant that could not be created by natural cross-pollination.

Exam Tip: Be sure to explicitly name both the digestive enzymes (cellulase and pectinase) and the chemical fusogen (Polyethylene Glycol / PEG) in your description of the steps.