Viva Voce: CO2 is Released During Respiration | Lab Manuals for Class 10 PDF Download

Q.1. When we say that plants and animals respire, where exactly is the process occurring?

The process of respiration occurs in the mitochondria of the cell. 

Q.2. Why germinating seeds or flower buds are ideal materials for this experiment (Method 2)?

Because their cells are active and they actively exchange the respiratory gases (CO₂ and O₂) as the oxidation of food takes place in these cells.

Q.3. Why do we pour water into the boiling tube containing germinating seeds through a thistle funnel?

Thistle funnels are used to add small amount of liquids (water) to an exact position. Thus, water is poured through a thistle funnel into the boiling tube containing germinating seeds as water is required for germination.

Q.4. How do germinating seeds respire—aerobically or anaerobically? Analyse.

Germination seeds respire aerobically. CO₂ is produced as an end product, when respiration occurs in the presence of oxygen.

Q.5. In which form energy is produced and utilised in our body?

ATP (Adenosine triphosphate)

Q.6. Aerobic respiration is different from anaerobic respiration. How?

Q.7. Why is respiration called a catabolic process?

As in this process, larger molecules are broken down into smaller units with release of energy.

Q.8. Does respiration occur in plants only at a specific time?

No, plants perform respiration at all the times.

Q.9. The germinating seeds are required to be kept moist during the experiment. Why so?

Germinating seeds are in growing stage and require water. If water is not available, the seeds will dry up and rate of respiration will slow down.

Q.10. Drop a NaOH (or KOH) pellet into the pale yellow phenol red indicator and observe? Reason out the cause of the change.

Pale yellow phenol red indicator (acidic medium) will turn into pink on addition with NaOH or KOH. As phenol red gives pink colour on addition of base.

Q.11. What is the gas that reacts with phenol red indicator (or with the lime water)?

CO₂

Q.12. Why is the experimental setup kept in sunlight in method 2?

To make the rate of germination much faster.

Q.13. Why do we use germinating seeds in this experiment (Method 1)?

Germinating seeds respires actively at a faster rate

Q.14. What is the roie of KOH in this experiment (Method 1)?

The KOH solution suspended in the flask absorbs the CO₂ released by germinating seeds.