NCERT 7th Class (CBSE) Science: Respiration in Organism

Question: What do you mean by ‘stomata’ apparatus?

Answer: Stomata apparatus means stomata along with nearby guard cells and other cells.

Question: What are the main organs of the respiratory system?

Answer: Main organs that help in respiration are :

1. Nostrils (The passages in the nose)
2. Trachea (Windpipe)
3. Bronchi
4. Lungs

Question: What chemical reaction occur during anaerobic respiration in yeast?

Answer: In yeast, the cellular glucose is converted into alcohol and carbon dioxide which give us energy.

Question: An athlete suffers from muscular cramps while running a race. How can you help him overcome the quips?

Answer: To relief from these cramps we should massage the affected part or take a hot bath.

Question: How does exchange of gasses occur in the following:

Answer:

1.  Fish: fish have special structure called girls. Dissolved oxygen is used from the water entering the gills. Gills are well supplied with blood for exchange of blood.
2. Cockroach: Cockroaches movement of draws air in and out of the opening called spiracles. These openings are present on the body surface and are connected internally with a network of branched air tubes (trachea) and their branches (Tracheoles).

Question: How are combustion and cellular respiration similar to each other? In what ways are they different?

Answer: Similarities – During cellular respiration the sugar molecules in food are form carbon dioxide and water and energy is given out.

C₆ H₁₂ O₆+ 60₂ → 6CO₂ + 6H₂O + energy

This is similar to the chemical reaction that occurs during burning or combustion.