Solution:

Explanation

Water cycle also called the hydrologic cycle is as described below: 

Final Answer

Hence, this is the process of water cycle in nature.

A: Endoplasmic reticulum

B: Golgi apparatus

C: Nucleus

D: Mitochondria

Solution:

Explanation

2% solution of the silver nitrate is involved in staining the golgi apparatus. Due to the impregnation of silver in the golgi apparatus,

the morphological structure can be studied post the staining procedure.

Final Answer

Hence, option B. i.e., Golgi apparatus is the correct answer.

Solution:

Explanation and Final Answer:-

Irrigation is defined as the supply of the water in the absence of rainfall with the help of manual or mechanical methods to the crops which is required for the optimum growth and yield.

The two methods which are water saving are Drip irrigation and Sprinklers irrigation.

• Drip irrigation- is also called trickle irrigation which involves dripping water onto the soil at very low rates (2-20 litres /hour) by a system of narrow plastic pipes fitted with outlets called emitters or drippers.

Water is applied close to the roots of the plants unlike surface and sprinkler irrigation, which involves watering the entire area of the ground. In the drip irrigation method, water is to be given more frequently ( a gap of 1-3 days)

than in the other methods and hence it provides a great moisture level in the soil in which plants can have optimum growth.

• Sprinkler irrigation system- allows the application of water under high pressure provided with the help of a pump. It irrigates the crops by sprinkling the water similar to rainfall through a small nozzle placed in the pipes.

Water is well distributed through a system of pipes and cisterns, sprayed thin into air and irrigates in most of the soil types usually,  due to its wide range of discharge capacity.

Solution:

Explanation:

Carbon-dioxide is the main greenhouse gas which creates a greenhouse effect in the atmosphere. 

Carbon dioxide is increasing in the atmosphere due to the excessive use of fossil fuels.

They are called greenhouse gasses as they work like a glass of a greenhouse and allows visible light to pass through it, but traps long wave radiations leading to an increase in temperature of the earth.

Besides carbon dioxide, other gasses like methane, nitrous oxide and water vapour also act as greenhouse gases. 

Final Answer:

carbon -dioxide is the main gas responsible for creating the greenhouse effect in the atmosphere.

Besides carbon dioxide, methane, nitrous oxide and water vapour is responsible for the greenhouse effect. These all gasses occur naturally.

The percentage of oxygen in air is:

A: 78 %

B: 0.03 %

C: 21 %

D: 80 %

Solution:

Correct Option is  - C -  i.e., 21%

Explanation:

The percent of oxygen in air is 21% in air. It is one of the most important gasses required for the respiration process and hence important for the survival of life on the Earth.

Air is a mixture of different gasses, it constitutes about 78% of Nitrogen, 21% oxygen, and 0.93% of Argon. It also contains a trace amount of other gasses like carbon dioxide, neon, hydrogen.

Thus, option A, B and D do not hold true.