Bihar Board Class 12 Biology Solutions Chapter 9 Strategies for Enhancement in Food Production Textbook Questions and Answers, Additional Important Questions, Notes.
BSEB Bihar Board Class 12 Biology Solutions Chapter 9 Strategies for Enhancement in Food Production
Bihar Board Class 12 Biology Strategies for Enhancement in Food Production Text Book Questions and Answers
Explain in brief the role of animal husbandry in human welfare.
Animal domestication is as old as the hunting phase of human civilization. After realizing the utility of domestic animals man started improving them by selective breeding. Animal husbandry is the agricultural practice of breeding and raising livestock.
It deaf with the care and breeding of animals which are useful to humans such as cows, buffaloes, pigs, goats, sheep, horses etc. It also includes poultry farming, fishing, sericulture, apiculture also. Honey bees (apiculture), silkworm (sericulture), prawns, crabs, birds, cattle, camels are used by human beings for products like honey, silk, meat, milk, wool, eggs etc. Animal husbandry practices help in better management and quality as well as quantity production of animal products.
It helps in developing disease-resistant breeds. With the help of techniques like in-breeding, out-breeding, interspecific hybridization, multiple ovulation and embryo transfer technology, new improved breeds are being produced. In dairy farming and poultry farming, selection of disease-free breeds, proper and safe farm conditions, proper feed and water, hygiene and health care, proper and hygienic storage of farm products are of paramount importance.
In apiculture, selection of suitable location for beehives, catching and hiving of group of bees, management of beehives in different seasons, hygienic handling and collection of honey and beewax, has made it possible to large-scale beekeeping industry. Pisciculture is devoted to catching, processing and selling of fish, shellfish and other aquatic animals.
Animal husbandry has brought a revolution in these industries and fanning of other domestic animals also.
If your family owned a dairy farm, what measures would you undertake to improve the quality and quantity of milk production?
Milk yield is directly dependent on the quality of breeds in the dairy farm. First of all breeds with high yielding potential and disease-free and resistant varieties should be chosen. Yielding potential also depends on the local conditions that should be looked after, they should it prop rly housed and provided with adequate water.
Care should be taken for the quality and quantity of fooder. Stringent cleanliness and hygiene aie very important for the cattle and the handler while milking, storage and transport of milk and its products. Cattle should be monitored regularly, identify and rectify the problems as soon as possible Veterinary doctor should be appointed for regular check-up.
What is meant by the term ‘breed’? What are the objectives of animal breeding?
A group of animals related by descent and similar in most characters such as general appearance, features, size, configuration etc. are said to belong to a breed. Animal breeding aims at the genetic improvement of domesticated animal species. Breeds of cow, buffalo and poultry are mated to get improved breeds of these.
Progeny produced by cross-breeding retain some useful characters and are better adapted then their parents. The males are studier and hardier than the parental species to work in fields or on mountains. Females produce more milk or eggs. Animal breeding helps in raising better population in shorter time than natural process.
Name the methods employed in animal breeding. According to you which one of the methods is the best? Why?
There are two main methods for animal breeding :
(a) Natural breeding, and
(b) Artificial breeding.
(a) Natural breeding may be random or controlled breeding.
In random breeding superior pedigree balls are kept along with grazing cows. In controlled breeding mating of native cows is done with superior exotic bulls. Superior dairy breeds are imported from foreign countries, e.g. improved hybrid varieties like Jersey-Sindhi, Ayrshire-Sahiwal and Brown-Swiss-Sahiwa! have been developed by controlled breeding.
(b) Artificial breeding is done by inseminating the native cows with the semen of superior bulls of exotic or indigenous breeds. It ensures good quality progeny, e.g. Buffaloes of Murrah breed are in good demand to improve the milch buffaloes.
Artificial breeding is the best method to improve the progeny because :
- It is more economical, there is no need to import ‘he whole animal, for e.g. only semen can be ordered for the purpose.
- Semen from one bull can inseminate a few thousand cows at far off places.
- One specimen can be used at different places at same time.
- It ensures good quality of the progeny.
- Less chances of wastage.
- Artificial breeding can be supported by techniques like superovulation and embryo transplantation. One superior cow can be induced to produce more egg, which are artificially inseminated and the embryo is transplanted to surrogate mother.
- The embryo can be preserved for further use.
What is apiculture? How is it important in our lives?
Apiculture is the maintenance of beehives for the production of honey. It is important in following ways like :
- It is an old cottage industry, nowadays it’s done on large scale and provides a good source of income.
- Honey is high nutritive value food and is used in medicines as well
- Beehive wax is used in various industries, for example in cosmetics, polishes etc.
- Honey is beneficial for diabetic patient and a household remedy for cold and cough,
- Sugars present in honey are easily assimilated and serve as a source of nourishment.
Discuss the role of fishery in enhancement of food production.
Fisheries indue rearing, catching, processing and selling of fish, shell-fish, crustaceans etc. Fish culture is known as pisciculture.
Fish and other edible sea animals form an excellent food. The importance of fish food is as follows :
- Fishery is of great importance to human beings, fish food contains more proteins than all other foods, it has little fat, good amount of vitamin A and D, rich source of iodine, easily digested.
- The by-products of fishing industry are liver oil, which is rich in vitamin C, D and E, A.
- Fish meat is a by-product of Fish oil or canning industry and serve as major food for animals.
- Fish proteins concentrate (FPC) are used as dietary supplement.
- Fish flour is easily digested by infants and used in cakes, biscuits, bread etc.
- Fish fertilizer are dry fish manure which are used for coffee, tea and tobacco plantation.
The nutrition experts consider fish meat next to mother’s milk so fish should form a part of our diet.
Briefly describe various steps involved in plant breeding.
Plant breeding is the purposeful manipulation of plant species to create desired plant progeny. The plants produced by breeding are better adapted for cultivation and environmental conditions, give better yields, are disease and pest resistant. The various steps involved in breeding are discussed as follows :
- Germplasm collection: It is the entire collection of plants or seeds having all the diverse alleles for all genes in a given crop. First all the different, wild varieties, species and relatives of the cultivated species are collected and preserved.
- The germplasm is evaluated and the desirable characters are identified. These selected plants are multiplied to obtained pure lines.
- Cross hybridization among the selected parents: The desired characters are combined and hybridized from two different parents, for example high protein content from one plant is hybridized with disease resistance from another plant. The hybrids have the genetic combination and characters from both the parents.
- The hybrids with desired characters are selected and self-pollinated for few generations to obtain homozygosity.
- The new breeds are evaluated for quality, yield, disease resistance etc., grown in research field under controlled conditions. These are tested for three growing seasons in open fields. The results are compared with the local cultivated crop and if suitable released in the market.
Explain what is meant by biofortification.
Biofortification is breeding crops with higher levels of vitamins and minerals, or higher protein and healthier fats. It is the best practical means to improve public health. Its main objectives are :
- Increased protein content and quality.
- oil content and quality
- increased vitamin content arid
- increased micronutrients and mineral content.
For example Atlas66 wheat have more proteins, maize hybrids have twice amount of lysine and tryptophan, rice with more iron content are commonly consumed.
Which part of the plant is best suited for making virus-free plants and why?
The plant pathogens like viruses are transmitted through the j propagules like root, tubers, bulb, rhizome etc. Their meristems (apical ‘j and axillary) are always free of virus. The healthy shoot tips of infected plants if grown by tissue culture can produce healthy plants. It is used. for producing potato, sugarcane, strawberry etc.
What is the major advantage of producing plants by micropropagation?
Micropropagation is the vegetative multiplication of plants under controlled conditions from tissues, organs of plants, e.g. root tip, shoot tip, embryo, stem, callus etc. It is used vastly in agriculture, horticulture and forestry. Its main advantages are :
- This technique is useful for propagation of commercially valuable plants which otherwise take a long time if grown under field conditions.
- It is very economical as a large number of clones can be produced in small space and very cost-effective too.
- It’s used in multiple shoot let production.
- It helps in producing embryos from somatic cells by tissue culture technique.
- Helps in producing disease-free plants.
Find out what the various components of the medium used for propagation of an expiant in vitro are?
The explant are cultured on a liquid, semi-solid or solid culture medium. The solid medium is prepared by addition of 1% Agar-agar or gelatin. Its major constituents include
- Inorganic nutrients like salts which provide all the essential macro and microelements,
- Organic nutrients which provide source of energy like sucrose, glucose, fructose, amino acids, glycine, vitamine etc.
- Growth harmones like auxins, gibberellins, cytokinins etc. Sometimes coconut milk, yeast extract or bean seed extract is also added. The amount and nature of nutrient medium may vary. All the apparatus is thoroughly sterilized.
Name any five hybrid varieties of crop plants which have been developed in India.
In India, a few varieties of lysine-rich maize is developed such as ‘Shakti’, ‘Rattan’ and ‘Protina’, as well as ‘Sonalika’ and ‘Kalyan Sona’ of wheat varieties, were developed.
Bihar Board Class 12 Biology Strategies for Enhancement in Food Production Additional Important Questions and Answers
Very Short Answer Type Questions
Which is the best solution to prevent the problem of crop diseases?
Seed treatment with fungicides and antibiotics is the best way to tackle diseases in crop plants.
Name some crop plants that are propagated vegetatively even though they do not bear seed.
Potato, Tapioca and Sugarcane.
What are three types of control measures for the different plant diseases?
What are Allotetraploids?
Those individuals that are produced by the multiplication of chromosome sets, which are initially derived from two different species.
Give an example of those plants which have turned out to be tripioids (originating apparently from unreduced gametes).
Apple and Pear.
What is germplasm?
The genetic material present inside the reproductive cells or germ cells is called germplasm.
What is gene pool? (H.P.Board, 2001)
The sum total of different types of all the genes and their allels present in a population or species.
Wha is hybrid vigour?
The superiority of the hybrids over either of the two parents in one or more traits is called heterosis or hybrid vigour.
Write down the importance of male sterility in plant breeding?
Plant breeders use male-sterile plants as female plants in artificial hybridizations to avoid self-pollination.
Why is quarantine a must before introduction of a plant species from a different country? (C.B.S.E. Delhi 2004)
Plant species are carefully observed for the presence of weeds, insects or disease-causing organisms before introduction to reduce the risk of entry of a pathogen in the country. This is quarantine.
Name some commony used mutagens.
U V rays, X-rays, cosmic rays, gamma rays, nitrous acid, EMS, nitromethyl urea.
What is surface sterilization?
The procedure of treating explant with specific antimicrobial chemicals to make them microorganism free.
What is totipotency?
Ability of a plant cell to give rise to a complete plant.
What is subculture?
A new culture vessel containing fresh culture media and a part of original culture as starting material.
What are somaclonal variations?
The variations observed among plants regenerated from tissue culture are called somaclonal variations.
What is the purpose of another culture?
Anther culture is used to obtain haploid embryoids.
What is meant by embryo rescue?
A technique of culturing young embryo, fertilised ovule or pollinated ovary to protect the development of embryo.
What is hybrid?
Hybrids are offsprings produced by crossing the parents with different characters.
Raising domesticated birds for economic purpose.
Name the protein types found in egg white.
Ovalbumin (70%) and Canalbumin (17%).
Short Answer Type Questions
What are intervarietal and interspecific hybridisation?
Intervarietal hybridisation is across between the two varieties of the same species whereas interspecific hybridisation is a cross between the different species of the same genus.
What are the aims of plant breeding?
Plant breeding is mainly concerned with the production of plants having desired characters such as high yield, better adaptation, resistance to diseases and pests etc.
What are the features of wild plants which are selected by man for his benefit?
Wild plants grow rapidly and produce a crop within a season, and wild plants store enough food reserves in their seeds to survive through drought.
What is plant introduction?
When a plant species is carried from its place of origin to a new place and cultivated, it is termed as plant introduction. It is an important method for crop improvement.
What is meristem culture?
Use of explant that contains pre-existing shoot meristems and produce shoots from them when cultured on a medium. Such a culture is called meristem culture.
What is callus?
An unorganised mass of cells is called callus. It is usually produced by culturing explant in tissue culture laboratories.
A superficial tissue developing in woody plants, usually through cambial activity, in response to wounding is also called callus. This tissue develops for protecting the injured surface.
Who coined the term totipotency? What does it means?
German botanist Gottlieb Haberlandt 1902 coined the term totipotency. Totipotency is the ability or capability of a cell to give rise to a complete organism when cultured in a suitable culture medium at appropriate temperature and aeration conditions.
What are somatic hybrids? What are their common uses?
Somatic hybrids are produced by fusion of somatic cells of two varieties of species. They are produced by somatic hybridisation. The cell walls of plant cells are removed by digestion with a combination of pectinase and cellulase. The naked protoplasts of two cells are induced to fuse by a solution of polyethene glycol (PEG) and a brief high voltage current. Such protoplasts when transferred to suitable culture medium, develop cell walls and begin to divide. These are used for gene transfer, transfer of cytoplasm and production of allopolyploids.
What is dedifferentiation and redifferentiation?
Transformation of mature cells into meristematic cells leading to the formation of callus is called dedifferentiation. Development of entire plants from the components cells of callus is called redifferentiation.
Discuss the role of plant tissue culture in increasing food production.
Plant tissue culture play various roles in increasing food production as :
- The callus culture and suspension culture is used to get cell biomass production.
- It may be used for biochemical isolation.
- It is used to regenerate plantlets.
- It is used for the production of transgenic plants.
- It is used for isolation of protoplasts.
Elaborate as to how biotechnology can be helpful in achieving sustainable agriculture.
Biotechnology can be helpful in achieving sustainable agriculture through the use of biofertilizers, biopesticides, disease resistant and insect resistant varieties. Microorganisms are used to prepare butter, yoghurt, cheese, idlis, dosa etc. Single-cell protein (SCP) can be produced from algae, bacteria, microbes etc. It is done in yeasts. It provides valuable protein-rich supplement in human diet. Microbes are employed to enhance the availability of nutrients to crops.
‘Biotechnology can greatly promote human welfare, but it can also be misused to increase human sufferings.’ Comment on the statement.
Biotechnology is the wise use of organisms for human welfare. It can be misused in many ways :
- Biopotenting may cause problem to one country.
- Biopiracy – developing countries may be misused by exploiting bioresources.
- Bioweapons – may be fatal to use.
- Transgene – its introduction may violate the integrity of a species.
Give a schematic representation of plant breeding.
Write a note on heterosis.
Heterosis is the reverse of inbreeding depression. When two unrelated individuals or lines are crossed, the performance of F1 hybrid is often superior to both its parents.
What are mutations?
Mutation is a sudden and heritable change in a character of an organism. It may arise due to a change in (i) chromosome structure, (ii) chromosome number, (iii) base sequence of the concerned gene. Mostly mutations are non-expressive. These may be spontaneous (natural) or induced by mutagens like physical mutagens (X-rays, gamma rays, etc.), chemical (EMS., sodium azide etc.)
Mutation breeding is used in plant breeding to develop improved varieties.
Long Answer Type Questions
(i) What is interspecific hybridisation? Explain the term by giving an example.
A cross between two different related species is called interspecific hybridisation. The progeny is different from both the parents. Sometimes the progeny combines the desirable features of both the parents. Examples is production of mule by a cross between female horse (mare) and male donkey. It inherits size from horse and sure-footedness, great endurance to hardship from donkey. It is more useful on high hills. However, with all its hybrid vigour, the mule is sterile and unable to reproducer.
(ii) Name the ways through which breeders create desired genetic variations in plants. Write short notes on any four of those. The different ways through which breeders create genetic variations in plants are (a) Domestication, (b) Germplasm collection, (c) Plant introduction, (d) Selection, (e) Hybridisation, (f) Polyploidy, (g) Mutation, (h) Genetic engineering.
(i) Plant introduction: When a variety (line or population) of any plant species is taken from one area into a new area (where it was not grown before) it is called as plant introduction. Plant introductions from other countries are valuable sources of germplasm. These provide us with many valuable crops. Example – potato, tomato, cauliflower. grapes, guava etc. are introduced crops. Soybean is a recently introduced crop. Introductions have also provided us with improved varieties of the existing crops. Example ‘Sonara-64’ variety of wheat and ‘Taichung Native 1’ variety of rice are introductions. These are dwarf varieties and provided the starting material for ‘Green revolution’ in our country.
(ii) Hybridization: The process of crossing of two species having desirable characters is known as hybridisation. This method produces genetic variations in the next progeny. It is a scientific improvement of plants by crossing of two varieties. It can also be called as the mating between lines of different genotypes. One parent is male and the other female; when they are crossed together the hybrids are produced. They are called F1 seeds. In F2 generation there will be segregation, recombination and independent assortment. Hybridization may be between different varieties of same species, then it is termed as intervarietal hybridisation. If a crop species is mated with other different but related species it is called interspecific hybridisation. Such variations are very important for plant breeding.
(iii) Mutation: Mutation is defined as “a sudden and heritable change in a character of an organism.” It may arise due to a change in any of the following : (a) chromosome structure, (b) chromosome number, and (c) base sequence of the concerned gene. Mutations occur in nature spontaneously at a very low rate. They are called spontaneous mutations. Mutant alleles are generally recessive. They produce harmful effects. Only about 0.1% of the mutant alleles are beneficial.
Mutations may be induced by mutagens which may be physical (X-rays, gamma rays, UV-radiations etc.), chemical (ethyl methane sulphonate (EMS) and sodium azide etc.). Mutation breeding is used in plant breeding to develop improved varieties.
(iv) Polyploidy: The condition in an organism, in which the number of complete chromosome sets is higher than the diploid number is called polyploidy. For example monoploids have V (sign’); diploids have 2n: triploids have 3n (3 chromosome sets) and so on.
Autopolyploidy: The variation of the number of chromosome sets arising within a species is called autopolyploidy. For example, in sexually reproducing organisms egg may be fertilized by more than one sperm, and resulting failure, mitosis and failure of meiosis during gamete formation. Autopolyploidy variety of tea in India. Allopolyploidy is produced in two steps – two different species are hybridized to produce F1 Then F2 is doubled in chromosome numbers, e.g. wheat, oat, tobacco.
Write short notes on the following :
(a) Callus and suspension cultures
(b) Meristem culture
(c) Embryo culture
(d) Anther culture
(e) Somatic hybridization
(a) Callus and suspension cultures: The division of explant makes a callus. Callus is unorganized mass of cells. It is kept in a medium having auxin 2,4D. The cells become meristematic and divide to give rise to a plantlet. In suspension culture the cells aid groups of cells are suspended in nutrient media they develop in/o plantlet.
(b) Meristem culture: In meristem culture, the shoot forms many shoots if kept in a nutrient media. The explant for it has nodes or shoot tips.
(c) Embryo culture: It is called “the excision of young embryos from the developing seeds and their cultivation on a nutrient media. Other embryos are cultured in vitro.” Examples are orchids.
(d) Anther culture: The haploids develop from the gametes or they develop from the unfertilized eggs. In lab they are made from male and female gametes. They are formed in Datura. The nucleus of pollen grain divides and give rise to pollen embryo to produce a callus.
Fig.: Production of homozygous lines using anther culture. The two parents are
shown to differ for only one gene, i.e., AA and aa. The same will be true even when they differed for many genes with the following difference: the number of different homozygous lines will be much larger than that shown here.
(e) Somatic hybridization: It is the process of producing somatic hybrids. The somatic hybrid is made by the fusion of somatic cells of two varieties or species. The cell wall is removed and the cells fuse
Fig. Somatic Hybridization
(a) Production of protoplasts using a combination of pectinase and cellulase
(b) protoplast fusion induced by PEG ultimately yields somatic hybrid cells
(f) Totipotency: It is the property of a cell to develop into a plantlets or full plant when kept in a nutrient medium. Carrot cells are totipotent.
(g) Biofertilizers: These are the organisms used to enhance the
availability of nutrients such as phosphate, nitrogen and phosphorus etc. Example: Rhizobia fix atmospheric N, into nitrates for the legume plant.
(h) Biopesticides: These are the biological agent used to kill weeds, insects and pathogens. These are chemicals. Some bacteria and fungi are used to control diseases of crops and weeds.
One Word Type Questions
Give the locational site of Imperial Veterinary Research Institute (IVRI).
Name the protein types found in egg white.
Ovalbumin, can albumin.
Which country is the native place of jungle fowl Gallus gallus?
Mention the ploidy of modern bread wheat Triticum aestivum.
Name the part of fruit from which mango juice is extracted.
Central Rice Research Institute.
Where is the FRI situated?
In which state of India, most of coffee is produced?
Name the plant from which coir is produced?
Name two plants which have been produced by artificial selection.
Wheat and maize.