CBSE Class 9 Biology Improvement in Food Resources MCQs Set 06

Answer: (d) All of these

Explanation:
1. M. S. Swaminathan led the green revolution in India, helped introduce Mexican wheat varieties and developed improved crops.
2. So all the statements are correct.

Teacher's Note:
1. He is called the father of the green revolution in India.
2. Norman Borlaug developed the Mexican dwarf wheat.

Answer: (a) Genetic variations

Explanation:
1. A mutation is a sudden change in the genetic material.
2. It produces new variations.

Teacher's Note:
1. Mutation breeding uses radiation to create useful variations.
2. Most mutations are harmful, a few are useful.

Answer: (c) Cross pollination by unwanted pollen

Explanation:
1. After emasculation the flower is covered with a bag.
2. This stops unwanted pollen from reaching the stigma.

Teacher's Note:
1. Only the chosen pollen is applied later.
2. The bag is removed after fertilisation.

Answer: (a) Genetically Modified Organism

Explanation:
1. GMO stands for genetically modified organism, an organism whose genes have been altered by genetic engineering.
2. Bt cotton is an example.

Teacher's Note:
1. Genes from another organism are inserted.
2. GMOs are made to improve crops.

Answer: (b) Zinc

Explanation:
1. Micronutrients are needed in very small amounts, and zinc is one.
2. Potassium, calcium and magnesium are macronutrients.

Teacher's Note:
1. Other micronutrients are iron, boron, copper and manganese.
2. Plants need 16 nutrients in all.

Answer: (b) It increases the number of friendly microbes

Explanation:
1. Manure adds organic matter (humus) to the soil and increases the number of useful microbes.
2. It also improves soil structure and water holding.

Teacher's Note:
1. Fertilisers are nutrient specific, easy to store and carry.
2. Manure is bulky.

Answer: (b) Biofertilisers

Explanation:
1. Biofertilisers contain living microbes like Rhizobium and blue-green algae.
2. They improve soil fertility, e.g. by fixing nitrogen.

Teacher's Note:
1. They do not pollute the soil.
2. They are cheaper than chemical fertilisers.

Answer: (b) Hybridisation

Explanation:
1. Hybridisation crosses varieties to combine a disease-resistance gene with other good traits.
2. Artificial insemination is used with animals.

Teacher's Note:
1. Wheat varieties resistant to rust were made this way.
2. Mutation breeding is another method.

Answer: (b) It encourages the build-up of diseases and pests that destroy that particular crop

Explanation:
1. Growing the same crop every year allows its pests and diseases to build up in the soil.
2. Rotation breaks this cycle.

Teacher's Note:
1. Rotation with legumes also restores nitrogen.
2. Mono-cropping also drains the same nutrients.

Answer: (d) Intergeneric

Explanation:
1. Crosses between different genera are called intergeneric.
2. Crosses between different species of one genus are interspecific.

Teacher's Note:
1. Crosses between varieties are intervarietal.
2. Triticale is an intergeneric hybrid of wheat and rye.

Answer: (c) Pesticides can be easily applied to individual crops

Explanation:
1. Because crops grow in separate rows, each can be sprayed, harvested and threshed separately.
2. In mixed cropping seeds are mixed and there is no pattern.

Teacher's Note:
1. The first, second and fourth statements describe mixed cropping.
2. Intercropping is more organised.

Answer: (b) Amaranthus, Chenopodium and Convolvulus

Explanation:
1. Amaranthus (chaulai), Chenopodium (bathua) and Convolvulus (hirankhuri) are weeds.
2. Sunflower, triticale, berseem and paddy are crops.

Teacher's Note:
1. Weeds compete with crops for water, light and nutrients.
2. Weeding is done by hand or by herbicides.

Answer: (b) Abiotic factors

Explanation:
1. Non-living factors such as temperature, wind, light and water are abiotic factors.
2. Living things are biotic factors.

Teacher's Note:
1. Both kinds of factors affect crops.
2. A community is a group of living species.

Answer: (a) Nagpuri

Explanation:
1. Nagpuri is a buffalo breed, like Murrah and Surti.
2. Gir, Red Sindhi and Sahiwal are cattle breeds.

Teacher's Note:
1. Murrah is the best known milch buffalo.
2. Cattle breeds are indigenous Bos indicus.

Answer: (d) Have a long lactation period

Explanation:
1. Exotic breeds like Jersey have a long lactation period and give a lot of milk.
2. Local breeds are more disease resistant.

Teacher's Note:
1. Cross breeding combines both advantages.
2. Lactation is the period of milk production.

Answer: (a) Broilers

Explanation:
1. Broilers are fast-growing chickens raised for meat.
2. Layers are raised for eggs.

Teacher's Note:
1. Broilers need protein-rich feed with vitamins.
2. They are marketed at about six to seven weeks.

Answer: (d) All of the above

Explanation:
1. Ranikhet disease, fowl pox and fowl cholera all affect poultry.
2. So all the options are correct.

Teacher's Note:
1. Vaccination prevents these diseases.
2. Clean housing also helps.

Answer: (a) Fowl

Explanation:
1. Aseel is an Indian breed of fowl known for its fighting nature and meat.
2. It is an indigenous breed.

Teacher's Note:
1. Leghorn is an exotic breed of fowl.
2. Indigenous breeds are hardy.

Answer: (b) Eggs of fishes

Explanation:
1. In fish culture, the young fish or fish eggs are called seed.
2. They are collected from rivers or bred in hatcheries.

Teacher's Note:
1. Seed can be obtained by induced breeding.
2. Good seed is important for fish farming.

Answer: (c) Blue

Explanation:
1. The increase in fish production by fish farming is called the blue revolution.
2. The green revolution is for food grains.

Teacher's Note:
1. The white revolution is for milk.
2. The silver revolution is for eggs.

Answer: (c) Apis mellifera

Explanation:
1. The Italian bee is Apis mellifera.
2. It is used widely in bee keeping because it gives a lot of honey.

Teacher's Note:
1. Apis dorsata is the rock bee.
2. Apis indica is the Indian bee.

Answer: (d) Development of new crop varieties with increased yield and disease resistance

Explanation:
1. The green revolution was the great increase in food-grain production through high-yielding and disease-resistant varieties.
2. Better irrigation and fertilisers also helped.

Teacher's Note:
1. It made India self-sufficient in wheat and rice.
2. It began in the 1960s.

Answer: (a) Plough - tilling the soil

Explanation:
1. The description is of the plough, which has a share, shaft, handle and beam.
2. It is used to till (loosen and turn) the soil.

Teacher's Note:
1. A hoe removes weeds.
2. A seed drill sows seeds.

Answer: (d) Mrigal

Explanation:
1. Mrigal feeds at the bottom of the pond.
2. Catla is a surface feeder, and rohu is a column feeder.

Teacher's Note:
1. This is why different species can be grown together.
2. It gives better use of pond food.

Answer: (d) Sickle, harvester, threshing, combine

Explanation:
1. Crops are cut by hand with a sickle or by a harvester.
2. Separating the grain from the crop is called threshing, done by a combine.

Teacher's Note:
1. A combine does harvesting and threshing together.
2. Winnowing separates grain from husk using wind.