Class 7 Science Chapter 16 MCQ

Most of the water present on earth is not fit for consumption by us. Sea and oceans contain salty water which cannot be drunk. Even most of the fresh water is frozen as ice in glaciers and polar regions. Hence, we are left with limited amount of water from lake, river and under the ground.

Snow and ice are frozen while water vapor is in gaseous state. Water from lake and river are in liquid state.

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

The upper limit of the layer where water is present between particles of soil and gaps between rocks is called water table and water below this layer is called groundwater.

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

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

Here, all the statements are correct for the causes for the shortage of water are.

22 March is celebrated as the World Water Day.

The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene is a minimum of 50 liters per person per day.

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

Every drop of water is precious for life to sustain on earth.

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

A pukka or cemented floor is usually impervious to water, inhibiting the seepage of rain water into grounds.

Rain is the source of water on earth. And about 71% of the earth’s surface is covered with water. Though, heavy rainfall is the source of water, not for water shortage.

Snow is also solid form of water. Water is present in liquid form in ocean, river, lakes, ponds and under the ground. Water is present in gas form as water vapor in the air or atmosphere around us. Water is present in solid form on snow covered mountains, glaciers and as ice caps on the poles of the earth.

The main source of groundwater is the rain. The impermeable rock does not allow water to pass through it. So, water starts collecting above the impermeable rock and fills the soil and permeable rocks completely with water up to the level known as water table. The underground layer of soil and permeable rocks in which water collects under the ground is called an aquifer.

Plants need water to obtain nutrients from the soil, and to make food by the process of photosynthesis. The scarcity of water will affect the nutrient uptake by the plants and the process of food making photosynthesis in plants. The plants will not be able to make sufficient food for themselves and for animals. Remember, plants help in bringing rain by releasing a lot of water vapor into the atmosphere through transpiration. Scarcity of water for plants will reduce transpiration also.

Rain is the ultimate source of fresh water. In very cold regions, water drops in the sky freeze to forms snow leading to snowfall. Snow is the solid form of water. The water which falls from clouds as rain or snow is called precipitation.

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

If there are less number of trees and plants in the forest, less rain water will seep into the ground. Lesser number of trees and plants in the forest will bring less rainfall. Deforestation leads to less rainfall as well as laser seepage of rainwater into the ground. This depletes the water table.

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

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

In ancient times, “Bawris” were mainly set up in cities and big towns for collecting water during drought periods, not “Big boros”.

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

The scarcity of water will affect the nutrient uptake by the plants and the process of food making (photosynthesis) in plants. So, due to scarcity of water, the plants will not be able to make sufficient food for themselves and for animals (including human beings). This will lead to severe shortage of food leading to famine.