Revision: Enhancement of Food Production Biology HSC Science (General) 12th Standard Board Exam Maharashtra State Board

The hydrostatic pressure which balances and prevents the osmotic inflow of water into concentrated solution is called osmotic pressure.

Osmotic pressure may be defined as the external pressure which should be applied to the solution in order to stop the phenomenon of osmosis, i.e., to stop the flow of solvent into the solution when the two are separated by a semipermeable membrane.

A group of cells having the same origin, same structure and same function is called ‘tissue’.

'Ex vivo growth of cells or tissues in an aseptic and nutrient-rich medium’ is called tissue culture.

or

Tissue culture is the technique of growing plant cells, tissues or organs under controlled laboratory conditions for crop improvement.

Single Cell Protein is the microbial biomass obtained from bacteria, yeasts, fungi or algae and used as a source of protein for human food or animal feed.

Biofortification is the breeding of crop plants to increase their content of vitamins, minerals, proteins or healthy fats in order to improve human nutrition and public health.

It is a livestock breeding and growing practice in agriculture.

Breeding between a superior male of one breed with a superior female of another breed is known as cross-breeding.

Apiculture is the rearing of honey bees for honey. It is called Beekeeping.

The rearing of honey bee to obtain honey and other commercially important products is known as apiculture or bee‑keeping.

Pisciculture or Fish culture is the process of breeding and rearing fishes in ponds, reservoirs (dams), lakes, rivers, and paddy fields.

Pisciculture (fishery) is the practice of breeding, rearing and harvesting fish in natural or artificial water bodies for food and other economic uses.

Zymology is an applied science which deals with the biochemical process of fermentation and its practical uses.

"Superbug" is a term used to describe strains of bacteria that are resistant to the majority of antibiotics commonly used today.

Antibiotics are chemical substances produced by microorganisms which can kill or retard the growth of other disease causing microbes even in low concentration. Antibiotic means “against life”.

Bioherbicides are living creatures such as microbes, fungi, insects, or other pathogens that are employed to restrict the population of undesired plants in agricultural fields, ponds, lakes, and so on.

The practice of rearing lac insects for the commercial production of lac is called lac culture.

The improvement or purposeful manipulation of heredity of crop plants for the production of new and superior varieties is called plant breeding.

The in-vitro technique of producing a large number of plants from a small piece of plant tissue under sterile conditions is called micropropagation.

The production of genetically identical plants from a single parent plant is called clonal propagation.

The branch of applied zoology that deals with the rearing of silkworms for the production of silk is called sericulture.

• Microbes help in energy production by synthesizing fuels such as ethanol, methane, hydrogen, and hydrocarbons.
• Gasohol, a mixture of gasoline and alcohol, is produced using microbes like Zymomonas mobilis and Thermoanaerobacter ethanolicus.
• Biogas is mainly methane produced by methanogenic bacteria such as Methanobacterium during anaerobic fermentation of cattle dung.
• Biogas plants use dung slurry to generate gas for cooking and lighting, while the leftover slurry serves as a good fertilizer.
• Some algae produce hydrogen gas from water in sunlight through a process called biophotolysis, using the enzyme hydrogenase.
• Microbes also play a role in petroleum formation, oil-spill cleanup, and enhanced recovery of petroleum, helping in sustainable energy management.

• Biofertilizers are living micro-organisms that improve soil fertility by increasing the availability of nutrients to plants.
• They are eco-friendly alternatives to chemical fertilizers, which degrade soil quality and reduce microbial life.
• Nitrogen-fixing microbes such as Rhizobium, Azotobacter, Azospirillum, and Frankia convert atmospheric nitrogen into usable forms.
• Legume–Rhizobium symbiosis forms root nodules that fix large amounts of nitrogen and enrich the soil for subsequent crops.
• Azolla–Anabaena symbiosis and cyanobacteria are widely used in paddy fields and significantly increase rice yield.
• Mycorrhiza (fungus–root association) enhances absorption of phosphorus and other minerals and protects plants from pathogens.
• Phosphate-solubilizing bacteria and fungi convert insoluble phosphates into forms available to plants.
• Biofertilizers improve crop yield, reduce fertilizer requirement, and help in sustainable agriculture and soil conservation.

• Animal Breeding
  Animal breeding is the scientific practice aimed at improving desirable traits and increasing the yield of animals and their products like milk, meat, and eggs.
• Breed
  A breed is a group of animals with common ancestry and similar characters such as size, appearance, and productivity.
• Inbreeding
  Inbreeding is the mating of closely related individuals for 4–6 generations, which increases homozygosity and helps in producing pure lines, but may reduce fertility.
• Outbreeding
  Outbreeding involves breeding of unrelated animals, including crossbreeding and interspecific hybridization, to remove inbreeding depression and improve performance.
• Modern Breeding Techniques
  Techniques like artificial insemination and MOET (Multiple Ovulation Embryo Transfer) are used to rapidly increase herd size and obtain high-yielding superior animals.

1. Poultry Farming
   Poultry farming involves the rearing of domesticated birds such as chicken, ducks, turkey, and fowls for the production of eggs and meat.
2. Requirements of Poultry Management
   Proper breed selection, housing, feed, water, hygiene, and disease control are essential for efficient poultry farm management.
3. Types of Poultry Breeds and Uses
   Leghorn is the best egg-laying (layer) breed, while Plymouth Rock, Rhode Island Red, Aseel, Brahma, and Kadaknath are preferred as broilers (meat birds).
4. Poultry Diseases
   Common poultry diseases include viral (Ranikhet, bird flu), bacterial (cholera, typhoid), fungal (aspergillosis), parasitic, and protozoan (coccidiosis) diseases.

• Sewage is liquid waste containing human excreta, organic matter, chemicals, and pathogenic microorganisms.
• Microorganisms in Sewage:
  Sewage contains bacteria, viruses, protozoa, fungi, algae, and nematodes, including disease-causing microbes.
• Preliminary Treatment:
  Large floating and heavy solid particles are removed by screening and grit chambers.
• Primary Treatment:
  Suspended solids settle in sedimentation tanks forming primary sludge, reducing organic matter and microbes.
• Secondary Treatment:
  Aerobic bacteria form flocs that degrade organic matter and significantly reduce BOD.
• Tertiary Treatment:
  Anaerobic digestion produces biogas, and treated effluent is disinfected and released or reused.