CBSE Class 10 Science Chapter 15: Our Environment

Every food chain in the ecosystem begins with………., which are the original source of food.

• Saprophytes

• Parasites

• Producers

• Herbivores

We should reduce the use of the plastic bags, bottles etc. because:

• They are not durable

• They are non-biodegradable

• They are made of toxic materials

• They react with the atmospheric gases

Among the following choose the correct option which contains only biodegradable items?

(i) Wood, paper, PVC

(ii) Paper, seeds, detergent,

(iii) Paper, animal excreta, wood

(iv) Wool, leaves, paper

• (i), (ii) and (iii)

• (i) and (iii)

• (ii), (iii) and (iv)

• (iii) and (iv)

Which among the following statements is incorrect in view of the plants?

• They convert the solar energy into mechanical energy

• They prepare their food from organic compounds

• They are also called producers

• They are the initial source of energy in a food chain

In a food chain the second trophic level is occupied by:

• Carnivores

• Autotrophs

• Herbivores

• Producers

Green plants utilize ……… percent of sun’s energy to prepare their food by the process of photosynthesis?

• 1%

• 10%

• 20%

• 99%

The process of accumulation of harmful chemical substances like pesticides, in the body of living organisms at each trophic level of a food chain is known as:

• Biological magnification

• Biological accumulation

• Chemical magnification

• Chemical accumulation

Which of the following may be a conclusion of the excessive exposure of humans to sun’s ultraviolet rays?

(i). Peptic ulcers

(ii). Eye disease like cataract

(iii). Damage to lungs

(iv). Skin cancer

• (i) and (iv)

• (ii), (iii) and (iv)

• (ii) and (iv)

• Only (iv)

Which among the following is a correct full form for DDT?

• Dichloro Diphenyl Trichloro ethane

• Dichloro Diphenyl Tetrachloro ethane

• Dichloro Decaphenyl Trichloro ethane

• Dichloro Diethyl Trichloro ethane

If 100 J energy is available at the producer level in a food chain then the energy available to the secondary consumer will be:

• 10 J

• 0.1 J

• 1 J

• 0.01 J