Gaseous exchange and respiration questions | form two Biology

Explain the adaptation of lungs for gaseous exchange

Answer / Solution

The following are the adaptation of lungs in gaseous exchange

1. They are spongy with air sacs to hold air
2. Air sacs are numerous in number to provide large surface area for gaseous exchange.
3. Air sacs have thin membranes to reduce distance for diffusion of gases,
4. Lungs surface is highly moist to allow dissolving of gases.
5. Densely surrounded by network of capillaries to transport dissolved gases to and from the lungs.
6. Always contain air to maintain lungs shape.

Give reasons why it is healthier to breath through the nose than through the mouth

Answer / Solution

The following are the reasons for breathing through nose is healthier than through the mouth.

1. The nose is normally hairly to filter out solid components and dust from air before it reaches the lungs.
2. The nose contains mucus which traps dust, microorganisms and other substances from air hence preventing them from reaching the lungs.
3. The nose surfaces warms cold air before it reaches the lungs.

Which of the following statements is Not true ?

• Plants respire all the time
• At night plants give out CO₂
• During the day the rate of photosynthesis exceeds that of respiration
• Plants only rspire at night
• The dark reaction of photosynthesis cannot take place during the  day

Answer / Solution

D [ Plants only respire at night ]

Distinguish between

Breathing and gaseous exchange

Answer / Solution

The following is the difference between breathing and gaseous exchange.

Breathing is the inhalation of oxygen and exhalation of carbon dioxide gases, while

Gaseous exchange is the movement of oxygen and carbon dioxide across a respiratory surface.

What is ATP ?

Answer / Solution

ATP stands for adenosine triphosphate, which is a form of energy produced during aerobic respiration in which oxygen is used to break down glucose to form energy, carbondioxide and water.