Class 8 Science Chapter 1 MCQ

Fertilizers are not environment friendly as they are chemical substances rich in particular nutrient. Though, they increase the crop yield, the repeated and excessive use of fertilizers in the same field reduces the soil fertility. It also pollutes water bodies as they get dissolved and washed away by rain and also seeps in the water table posing threats to humans.

Some crop plants need transplantation, not all. Rest of all statements are correct. Hence, your answer will be option [C].

Ploughing of the soil during soil preparation creates spaces in the soil thus, leading to aeration and the soil also loosens which promotes the growth and survival of earthworms and microbes and release of nutrients in the soil.

If the field is dry for cultivation of crops, the soil preparation is done accordingly before sowing of crops. Preparation of dry soil includes adequate watering to restore the moisture content and then tilled and ploughed to allow growth of microbes and aeration. Finally, soil is turned and its crumbs are levelled and manures are mixed. The soil is ready for sowing of crops in the field.

The ginger is a modified underground stem, which is propagated vegetative by stem (rhizome) cultivation. It does not propagate by roots, leaves or seeds.

Harvesting is a process of cutting matured crops from close to the ground. It is done manually using a sickle.

Organic manure are obtained from decomposition of plant and animal wastes that are rich in nutrients and humus. But all nutrients might not be present in a proportionate amount in it, thus will not solve the problem if soil is particularly deficient in one or more specific nutrient.

Here, all the statements are associated with seed drill. Hence, your answer will be option [D].

Fish is good for health, we get cod liver fish oil from fish, which is rich in Vitamin-D.

Here, all the options are correct. Hence, your answer will be option [D]

Irrigation is the supply of water to crops at regular intervals as water or moisture is necessary for seed germination, growth and other physiological processes. Moreover, the plants readily absorb nutrients in dissolved from along with water through root hairs of roots. It does not protect crops from frost and hot air currents and manure not irrigation improves soil texture.

Conversion of dead decaying matter into ammonia and then into nitrites and nitrates by nitrifying microbes, called “Nitrification”. Conversion of air nitrogen into nitrites and nitrates by nitrogen microbes, called “Nitrogen fixation”. Conversion of nitrites and nitrates from decaying organic matter into gaseous nitrogen by denitrifying microbes, called “Denitrification”.

Hoe is a simple tool used for removing weeds from the field and loosening of soil, it works like a blade, pulled by the animals in the field. Plough is used for tilling of soil; axe is used for cutting trees and cultivator is another tool implemented for ploughing.

Dried neem leaves are added to stored grains, so as to prevent damage from pests. Hence, your answer will be option [D].

Seeds placed deep into the soil may fail to germinate. Rest, all the statements are correct. Hence, your answer will be option [D].

Option A is correctly suggesting the harmful effects of weeds. Weeds are the undesirable plants that grow along the main crops. Removal of weeds is necessary because they interfere and affect the major crop’s growth, by competing for light, water, nutrients and space. They also interfere during harvesting procedure. Weeds do not help in healthy growth of crop plants.

The ploughed field may have big pieces of soil called crumbs. It is necessary to break these crumbs with a plank. The field is levelled for sowing as well as for irrigation purposes. The levelling of soil is done with the help of a leveller.

Weedicides are sprayed during the vegetative growth of weeds “before” flowering and seed formation. Rest, all the statements are correct. Hence, your answer will be option [D].

The process of loosening and turning of soil is called tilling and ploughing. It is the first step, in preparation of soil for cultivation of crop. Ploughing is done using a plough, made of wood or iron.

The supply of water to crops at different intervals is called irrigation. Pulley system, chain pump, dhekli and rahat (Lever system) are traditional methods of irrigation whereas sprinkler system and drip irrigation are the modern methods of irrigation.

Here, all the options are correct (may include in possibilities). Hence, your answer will be option [D].

Fertilisers are chemical substances which are rich in a particular nutrient. Some examples of fertilisers are urea, ammonium sulphate, super phosphate, potash, NPK (Nitrogen, Phosphorus, Potassium). The use of fertilisers has helped farmers to get better yield of crops such as wheat, paddy and maize.

Paddy, maize, soya-bean, groundnut, cotton, etc., are kharif crops. Rabi crops are wheat, gram, pea, mustard and linseed. Thus, wheat is not associated in kharif crops. So, your answer will be option [D].

Here, all the options are associated with animal husbandry. Hence, your answer will be option [D].

Drip system is the method of irrigation which conserve water and avoids wastages as water is made to fall drop by drop at the position of roots. It is the best technique for watering fruit plants, trees and gardens. Sprinkler system is also a modern method of irrigation that efficiently uses of water in the form of sprinklers. It is useful for uneven lands, while pulley and lever systems are traditional methods of irrigation where a lot of water is wasted.