Soil Composition

Q.

What is the colour of Iron oxide?

Q. Question 1
How is soil formed?

Q.

Hydrated soil appear Red in colour.

Q. which organism secretes organic acids , break down rocks and help is soil formation?

Q. Plants do not grow well in:

1. Extremely dry soil
2. Fertile soil
3. Manure added soil
4. Humus-rich soil

Q.

Give one word for special group of bacteria which disintegrate simple organic substances into inorganic compounds.

Q.

How is humus formed?

Q.

In addition to the rock particles, the soil contains.

1. Air and water.

2. Water and plants.

3. Minerals, organic matter, air, and water.

4. Water, air, and plants.

Q.

Are fungi decomposer?

Q.

Most of the fungi are harmful for human beings as they cause skin diseases and food poisoning but the biggest role of fungi in nature is:

1. Decompose the dead organisms and cleans up the environment

2. Source of antibiotics

3. Fermentation

4. Increasing the absorption of phosphate through mycorrhizal association

Q.

How living organisms help in the formation of soil? Give examples.

Q. Question 18
Top-soil contains the following

(a) Humus and living organisms only
(b) Humus and soil particles only
(c) Humus, living organisms and plants
(d) Humus, living organisms and soil particles.

Q. Humus is a major factor in deciding the soil structure.

1. True
2. False

Q. is one of the major factors that determines the soil structure and makes the soil more porous.

1. Lichen
2. Saline water
3. Sun
4. Humus

Q. The top most layer of soil contains

1. Humans and soil particles
2. Humus, living organism and soil
3. Human, living organism and plants
4. Human and microorganism

Q. Identify the constituents of soil from the following:

1. Mineral
2. Salt
3. Gravel
4. All of the above

Q. Soil is formed by the _____.

1. Formation of rocks
2. Arrangement of layers of sand
3. Breaking down of rocks
4. Arrangement of rocks

Q. Soil is a mixture of:

1. All the above
2. Air and water
3. Minerals
4. Dead and living organisms

Q. ............... helps in maintaining the supply of nutrients to the growing plants.

1. Herbivores
2. Carnivores
3. Decomposers
4. Omnivores

Q. The major source of formation of soil is:

1. Rocks
2. Snow covered mountains
3. River beds
4. Volcanoes

Q. Weathering of rocks occurs due to:

1. Strong winds
2. Flowing water
3. Heating and cooling of rocks
4. All of the above
   

Q. Humus is defined as

1. Physical texture of soil
2. Chemical composition of soil
3. Decomposed organic matter in soil
4. None of the above

Q. Plants do not grow well in:

1. Sand
2. Fertile soil
3. Manure added soil
4. Humus

Q. Why is organic matter (humus) an important part of soil?

1. It can break down organic pollutants
2. It helps to improve water infiltration
3. It converts nitrogen in the air into nitrates used by plants
4. It is rich in nutrients, which is important for fertility

Q.

Question 20
Major source of mineral in soil is the:

(a) parent rock from which soil is formed
(b) plants
(c) animals
(d) bacteria

Q. Which of the following factor does not help in the formation of soil?

1. Wind and water
2. Rocks and temperature
3. Decomposed plants and animals
4. Water accumulation

Q. Which of the following convert the dead plants and animals to humus?

1. Chemicals
2. Scavengers
3. Decomposers
4. Consumers

Q.

Question 3
How are living organisms dependent on the soil? Are organisms that live in water totally independent of soil as a resource?

Q. The rotting dead matter in the soil is called:

1. Humus
2. Minerals
3. Petrification
4. Decomposition

Q.

Question 18
Top-soil contains the following

(a) Humus and living organisms only
(b) Humus and soil particles only
(c) Humus, living organisms and plants
(d) Humus, living organisms and soil particles.