Class 7 Science Chapter 16 MCQ

According to the recommendation of United Nations (UN) minimum 50 liters of water per person per day should be provided. Hence, three buckets (nearly 60 liters) of water is sufficient for a person for one day.

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

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].

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

22 March is celebrated as the World Water Day.

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

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].

Water cycle does not involve rainwater harvesting. Rainwater harvesting involves recharging the groundwater.

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

The process of seeping of water into the ground is called “infiltration”.

All are the effect of acute scarcity of water on plants, except shortage of carbon dioxide. Because plants give us oxygen, not carbon dioxide. Due to scarcity of water the plants will not be able to make sufficient food for themselves and for human beings also. Due to decrease photosynthesis caused by the scarcity of water the plants will not be able to release sufficient oxygen into the air, shortage of food and lesser rainfall. But shortage of CO2 is incorrect.

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.

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.

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.

Rain is the source of water on earth. And about 71% of the earth’s surface is covered with water.

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 shortage of water. Hence your answer will be option [D].

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.