Write short notes
1. Sacred groves
Ans.
(1) The forest protected or conserved in the name of God (on religious grounds) and considered to be sacred is known as sacred grove or Devrai.
(2) Sacred groves are in fact sanctuaries conserved by the society and not by the government forest department.
(3) It has special protection, as it has been conserved due to special religious importance.
(4) Sacred groves are present not only in Western Ghats of India but in the entire country.
2. Lake Tapping
Ans.
(1) Lake tapping is a process in which a tunnel is dug out near the bottom of a lake upto the water-rock contact of the lake. The final layer of the rock is then blasted with the help of dynamite which provides the inflow of water into the tunnel with more speed.
(2) It is done to facilitate the generation of electricity when the water level goes down in peak summer.
(3) Thus, it also helps the areas suffering with drought due to scarcity of water during summer.
3. Nuclear Power Plant
Ans.
(1) In a nuclear power plant, uranium or plutonium are used as fuel.
(2) During the fission of nuclei of atoms like uranium or plutonium, the nuclear energy is converted to thermal energy.
(3) This thermal energy is used to heat the water present in a boiler. Steam of very high temperature and pressure is generated and directed on the blades of the turbine.
(4) The kinetic energy produced in the steam is then used to drive the turbine.
(5) The turbine rotates the generator connected to it which in turn produces electrical energy.
4. Problems due to nuclear power plant
Ans.
(1) Improper nuclear-waste storage and disposal result in environmental contamination.
(2) Accidental leakage of nuclear radiation can lead to lethal disaster.
5. Collar cells
Ans.
(1) Collar cells are special types of cells present in animals belonging to phylum Porifera.
(2) Collar cells help in movement of water within the body.
6. Starfish
Ans.
(1) Starfish belongs to phylum-Echinodermata.
(2) Starfish is exclusively found in the ocean.
(3) Starfish is triploblastic, eucoelomate and radially symmetrical. Larval forms however are bilaterally symmetrical.
(4) Starfish uses tube feet locomotion and capturing the prey.
(5) Starfish has a good ability of regeneration.
7. Mammals
Ans.
(1) Presence of mammary glands is the typical character of members belonging to class Mammalia.
(2) Exoskeleton is in the form of hairs or fur.
(3) They are warm blooded animals.
(4) Their body is divided into head, neck, trunk and tail.
(5) Digits of mammals are provided with nails, claws or hooves. For e.g. Elephant, human, kangaroo, dolphin, bat, etc.
8. Probiotics
Ans.
(1) Probiotics are milk products containing active bacteria like Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidium, etc.
(2) These bacteria maintain the balance of intestinal micro-organisms by increasing the population of microbes that help in digestion and decreasing the population of harmful microbes such as Clostridium.
(3) They also improve resistance and lower the ill effects of harmful substances formed during metabolic activities.
(4) When we take antibiotics, the useful microbes in alimentary canal become inactive. These microbes can be made active by consuming probiotics.
9. Microbial Enzymes
Ans.
(1) The enzymes obtained by microbial processes are active at low temperatures. Hence, the process of dirt/muck removal can occur at low temperatures when enzymes are mixed with detergents and energy can be saved.
(2) Certain enzymes can act specifically on different types of stains (starch, protein, oils, etc.) and hence enable more effective removal of such stains when mixed with detergents.
(3) Corrosion is a common problem in chemical industries. Using anti-corrosive instruments increases the production cost. However, while using microbial enzymes costly anti-corrosive instruments are not required.
(4) In microbial enzymatic reactions, elimination and decomposition of waste material is avoided and enzymes can be reused. Thus, microbial enzymes are eco-friendly.
10. Bio-fuels
Ans.
(1) Biofuels are renewable sources of energy.
(2) They are available in solid (dung, crop residue), liquid (vegetable oils, alcohol) and gaseous (gobar gas) forms.
(3) Biofuels are easily available in sufficient amounts.
(4) They are reliable fuels of the future.
11. Land Oiling sites
Ans.
(1) Landfill sites are located away from the residential area.
(2) In this method of waste disposal, large pits are dug in an open area.
(3) These pits are lined with plastic sheets to prevent soil pollution caused by leaching of toxic and harmful substances into the soil.
(4) The compressed degradable waste is dumped into the pit and covered with layers of soil, sawdust, leafy waste, specific biochemicals and sometimes the bioreactors are mixed for better aeration. This completely filled pit is sealed with soil slurry.
(5) Microbes present in soil and other layers decompose the waste. As a result, best quality compost is obtained after few days which can be removed and such sites can be reused.
12. Microbial inoculants
Ans.
(1) Microbial inoculants are produced by the process of fermentation and are either sprayed on seeds before sowing them or can be released into plants.
(2) Microbes in the inoculants, supply nutrients and help in plant growth. They also improve the quality of food.
(3) A solution containing Azotobacter and artificial nitrogenase is used in organic farming.
(4) Soil pollution caused due to chemical fertilizers can be prevented using such microbial inoculants.
13. Bio-insecticides.
Ans.
(1) Bioinsecticides are insecticides derived from natural biological agents.
(2) Bacterial and fungal toxins which can destroy pests and pathogens can be directly integrated into plants with the help of biotechnology.
(3) Being toxic to insects, they do not consume the plants.
(4) Similar to bacteria, some species of fungi and viruses are useful as pesticides.
14. Organ and Body Donation.
Ans.
(1) In recent times people have a more liberal view behind the concept of organ and body donation and believe that after death our body should be useful to other needful persons so that their miserable life would become comfortable.
(2) Also, awareness about these concepts is increasing in our country and people are voluntarily donating their bodies.
(3) Life of many people can be saved by organ and body donation. Blinds can regain their vision. Life of many people can be rendered comfortable by donation of organs like liver, kidneys, heart, heart valves, skin, etc. Similarly, body can be made available for research in medical studies.
(4) Many government and social organizations are working towards increasing the awareness about body donation.
15. Green Revolution
Ans.
(1) Green revolution is the agricultural revolution that took place in India by application of various methods for harvesting maximum yield from minimum land.
(2) Improved dwarf varieties of rice and wheat, proper use of fertilizers and pesticides and water management has contributed to green revolution.
(3) Dr. Norman Borlaug and Dr. M.S. Swaminathan have valuable contributions in green revolution.
16. White Revolution
Ans.
(1) White revolution involves improved production of dairy and dairy products
(2) Dr. Verghese Kurien was associated with the white revolution in India.
(3) He put the cooperative dairy movement of Anand, Gujarat at an all-time high status.
(4) During the process of attaining self-sufficiency of dairy products, various experiments were performed for quality control, newer dairy products and their preservation, thus boosting the white revolution.
17. Blue Revolution
Ans.
(1) Blue revolution involves fisheries and improved production of aquatic organism (aquaculture).
(2) Farm ponds and fishes are very common in the East Asian countries. Apart from this people began cultivating other aquatic plants and animals too.
(3) The Government of India vowed to increase the production by encouraging the people for pisciculture by launching the ‘Nil-Kranti Mission -2016 (NKM-16). 50 – 100% subsidies are offered in this case.
(4) Marine (shrimp and lobsters) and freshwater (Rohu, Catla and other fishery products) fisheries are being carried out on a large scale.
18. Biotechnology
Ans.
(1) The technique of bringing about improvements in living organisms by genetic modifications and hybridization, for the welfare of human beings is called ‘Biotechnology’.
(2) Biotechnology is used in the field of agriculture in order to improve crop variety and yields by techniques such as genetic modification, hybridization, etc.
(3) Techniques such as artificial insemination and embryo transfer are useful in animal husbandry to improve quality and/or quantity of animal products like milk, wool, meat, etc.
(4) Biotechnology has applications for the welfare of human health in diagnosis and treatment of diseases using vaccines, interferons, antibiotics, etc.
19. Addiction
Ans.
(1) Peer-group influence is stronger in case of adolescents. Adolescents always prefer the company of friends and follow their good or bad habits instead of following advice of parents and teachers, thus leading to various addictions.
(2) Children in their early age try upon tobacco, cigarette, gutkha, alcoholic drinks, drugs, etc. due to either peer-group pressure or symbol of high standard living or as an imitation of elders. However, it may lead to addiction to such deadly substances.
(3) Temporarily intoxicating drugs of plant origin and some chemicals may permanently damage the human nervous system, muscle system, heart, etc.
(4) Persons spending the time with cell phones for several hours are usually unaware of the surrounding. This is also a sort of addiction and leading to endangering of the social health.
20. Various ways for stress management
Ans. The various ways for stress management include the following:
(1) Communication with friends, peers, cousins, teachers, family members, etc.
(2) Fostering hobbies like photography, reading, cooking, sculpturing, drawing, etc.
(3) Physical activities like sports, regular exercising, yoga, etc.
(4) Inculcation of character traits like time management, planning.
21. Budding in Hydra
Ans.
(1) In Hydra, under favourable conditions, the regenerative cells of body wall are used for reproduction in the process of budding.
(2) When Hydra reaches maturity, body wall begins to form an outgrowth from the stalk of the adult. It is called bud. This bud develops into a young Hydra.
(3) The dermal layers and the digestive cavity of the young Hydra are continuous with that of the parent Hydra. The young Hydra gets nourishment from the parent.
(4) When the young Hydra is sufficiently developed, it breaks off from the parent Hydra. Then, it leads an independent life.
22. In-vitro fertilization
Ans.
(1) IVF is a technique in which fertilization is brought about in the test tube. Sperm is injected into the ovum using a micropipette.
(2) The embryo formed after fertilization is implanted in the uterus of a woman at the appropriate time.
(3) Childless couples, who have problems like less sperm count, obstacles in oviduct, etc., can use IVF technique for having a child.
23. Reasons of infertility
Ans. Various reasons of infertility are as follows:
(1) In case of women, irregularity in menstrual cycle, difficulties in oocyte production, obstacles in the oviduct, difficulties in implantation in uterus and many other reasons are responsible for this.
(2) Absence of sperms in the semen, slow movement of sperms, anomalies in the sperms are the reasons in case of males.