Bio f4 chap 8

Question 1

Predict what will happen to a fish if its gills are torn after being caught in a net

Answer 1

• damaged gills reduce the total surface area for an efficient gaseous exchange
• may die due to lack of oxygen

Question 2

How do abdominal muscles help insects to breath?

Answer 2

• inhalation: the abdominal muscles relax and the spiracle valves open.
• reduces the internal pressure of the trachea causing air to be drawn into the trachea through the spiracle
• exhalation: the abdominal muscles contract
• increases the internal pressure of the trachea forcing air out through the spiracle

Question 3

How does the usage of an inhaler help an asthmatic patient to breathe?

Answer 3

• reduces inflammation
• opens up the bronchoile tubes so that air can flow easily

Question 4

Explain why the gaseous exchange becomes less efficient for an emphysema patient.

Answer 4

• alveoli walls become damaged
• surface area of the alveoli is reduced
• gaseous exchange becomes less efficient

Question 5

Why a transportation system is not required to transport respiratory gases in insects?

Answer 5

• supplied with tracheole
• directly enters the cell to enable gaseous exchange

Question 6

Why are thee lungs of amphibians not as efficient as human lungs?

Answer 6

• do not have ribcage and diaphragm (help in the expansion and compression of the lungs)

Question 7

The diaphragm of an individual no longer functions normally due to an accident. Explain how this condition affects the breathing mechanism of the individual.

Answer 7

• breathing becomes difficult
• volume and air pressure of the thoracic cavity cannot be increased nor decreased

Question 8

How does an increase in heartbeat rate during an emergency help a person to face the emergency?

Answer 8

• oxygenated blood to flow to cells at a faster rate
• enables cellular respiration to occur at a faster rate
• supply extra energy required during the state of panic
• carbon dioxide can be expelled at a faster rate

Question 9

A hardcore smoker can easily suffer from a prolonged cough. Explain how this condition affects the function of the respiratory system.

Answer 9

• the heat generated from cigarettes dries up the tracheal wall and damages cilia
• cilia produce more mucus
• coughing is a reflex action to expel mucus
• cigarette smoke damages the alveoli, reducing the total surface area of gaseous exchange
• causes emphysema

Question 10

Another illness that may be easily contracted by a hardcore smoker.

Answer 10

• lung cancer
• carcinogens in cigarettes induce the growth of cancer cells

Question 11

Explain the effects of tar that is present in cigarette smoke on the smoker.

Answer 11

• tar that is deposited on the surface of alveoli, blackens them
• reduces efficiency of gaseous exchange and may cause cancer

Question 12

One of the effects of emphysema is the loss of elasticity in the alveolus. Explain the effect of this on gaseous exchange.

Answer 12

• less air is inhaled and exhaled
• breathing difficult
• air trapped in the alveoli may cause the alveoli to burst, producing a large air space in the alveoli
• less total surface area for gaseous exchange

Question 13

Why the rate of oxygen supply to human cells is faster than the rate of oxygen supply to fish cells if both are of the same size.

Answer 13

• humans have diaphragm and intercostal muscles to aid in the breathing mechanism
• not found in fish
• humans have a muscular heart that is able to pump oxygenated blood to the whole body faster

Question 14

Air pollution makes breathing difficult in animals and humans. If you are a scientist, which animal will you choose as an indicator of pollution level in a particular area? Explain the justification of your choice.

Answer 14

• frog
• although frog possesses a pair of lungs, the main respiratory organ is the skin
• unlike the heart, the air that diffuses through the skin is not filtered
• therefore, air pollution may cause the skin to be clogged by tiny particles
• clogged skin reduces the efficiency of gaseous exchange and cause death
• thus, frogs are more sensitive to air pollution compared to other vertebrates

Question 15

All mammals breath through the lungs as with mammals that live in the sea such as whales. How does the whale breathe in water?

Answer 15

• whales are able to store a very high concentration of oxygen in their blood and muscles
• they inhale at the sea surface and hold their breath when submerging
• body metabolism and heartbeat is reduced when whales dive
• the arteries in some parts also constrict to reduce blood circulation to that particular part to save oxygen consumption
• the saved oxygen is channelled to other important body parts such as the heart, sensory organs and brain
• a whale is able to hold its breath for approximately 50 minutes before rising to the sea surface to breathe