Free Natural Resources 01 Practice Test - 9th Grade
Question 1
Since decades, Antarctica has been a place of intense scientific research. Various countries have established their bases in Antarctica to study the impact of climate change. The ozone hole was discovered in 1985 in Antarctica. Which of the following is true regarding ozone hole?
Ozone hole is aggravated due to modernisation and use of technology without environment sustainability.
Ozone hole is a portion of the atmosphere where the concentration of ozone is the most.
SOLUTION
Solution : A and C
Ozone hole region in Antarctica is due to thinning of the stratospheric ozone layer. Ozone hole is caused by increasing concentrations of ozone-depleting chemicals in the stratosphere that come from spray cans, refrigerants, and air conditioners.Once they reach the ozone layer, they will react with the ozone molecules.This will result in a reduction of the ozone layer. In the absence of ozone layer, there will be a direct exposure to ultraviolet rays of the Sun which can cause a variety of health-related issues such as cancer, mutations, etc.
Question 2
Humus is a major factor in deciding the soil structure.
SOLUTION
Solution : A
Humus is a major factor in deciding the soil structure because it causes the soil to become more porous and allows water and air to penetrate deep underground.
Question 3
The factors like water, wind and living organisms influence soil formation.
SOLUTION
Solution : A
Soil formation is influenced by physical, chemical and biological processes. Physical factors like water and wind, chemical processes like hydration, biological factors like living organisms do influence soil formation.
Question 4
Most of the fresh water on Earth surface is found in:
SOLUTION
Solution : C
Out of the 3% of the fresh water found on the Earth's surface, majority is found in the form of glaciers. Almost 90% of the fresh water of Earth's ice mass is in Antarctica. The rivers and underground water are fresh water bodies while ocean water is saline.
Question 5
The process which involves the conversion of nitrates in the soil into atmospheric nitrogen is known as ______.
SOLUTION
Solution : B
The nitrates which are formed by the process of nitrification are utilized by the plants. The excess nitrates in the soil are released back in the atmosphere as atmospheric nitrogen by denitrifying bacterias. This process is known as denitrification.
Question 6
Which of these processes helps in nitrogen fixation?
SOLUTION
Solution : B
Nitrogen fixation is an essential biological process by which nitrogen in the atmosphere is converted into ammonia. Lightning is one of the physical processes that convert nitrogen into oxides of nitrogen. These oxides then dissolves in water to form nitrates and fall on land along with rain.
Question 7
Which among the natural cycles is the reason for the seas and oceans not drying up?
SOLUTION
Solution : C
The whole process in which water evaporates from the surface of seas and oceans and falls back on land as rain and later flows back into the sea via rivers is known as water-cycle. This is one of the ways in which the water present on earth is circulated all over the Earth.
Question 8
Oxygen from atmosphere is used up for processes such as
SOLUTION
Solution : B and C
Oxygen from the atmosphere is used for processes such as combustion and resipration. Oxygen is added up to the atmosphere by the process of photosynthesis. Transpiration is the process by which water is lost in the form of water vapour from the parts of the plants.
Question 9
The oxides of nitrogen and sulphur dissolve in rain to give rise to acid rain.
SOLUTION
Solution : A
The fossil fuels like coal and petroleum produces oxides of nitrogen and sulphur when they are burnt. These oxides are mixed up with rain water which give rise to acid rain.
Question 10
Which of the following constitute the abiotic components of the biosphere?
SOLUTION
Solution : A, B, and D
Abiotic factors or components are mainly referred to all the non-living things in the biosphere. Air, land,water, sunlight are the examples of abiotic factors. These factors help in sustaining
life on Earth.