State whether the following statements are true or false. Justify your statement. [5 MARKS]
(1) During heavy exercise, the breathing rate of a person slows down.
(2) Plants carry out photosynthesis only during the day and respiration only at night.
(3) Frogs breathe through their skin as well as their lungs.
(4) At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our respiratory systems.
(5) Glucose breaks down into lactic acid in the absence of oxygen.
State whether the following statements are true or false. Justify your statement. [5 MARKS]
(1) During heavy exercise, the breathing rate of a person slows down.
(2) Plants carry out photosynthesis only during the day and respiration only at night.
(3) Frogs breathe through their skin as well as their lungs.
(4) At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our respiratory systems.
(5) Glucose breaks down into lactic acid in the absence of oxygen.
Statement and justification: 1 Mark each
(1) False. During heavy exercise, more oxygen is required to meet extra demand of energy. Therefore breathing rate increases.
(2) False. Photosynthesis occurs in the presence of sunlight. Respiration is a continuous process and occurs all the time (day and night).
(3) True. Frogs breathe through skin as well as through lungs. Thus they have moist-slippery skin and lungs to help them breathe on both land and water.
(4) True. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our respiratory systems. That is why mountaineers carry oxygen with them.
(5) True. Muscle cells break down glucose into lactic acid with the release of energy in the absence oxygen during heavy activities. This process is called anaerobic respiration.
Statement and justification: 1 Mark each
(1) False. During heavy exercise, more oxygen is required to meet extra demand of energy. Therefore breathing rate increases.
(2) False. Photosynthesis occurs in the presence of sunlight. Respiration is a continuous process and occurs all the time (day and night).
(3) True. Frogs breathe through skin as well as through lungs. Thus they have moist-slippery skin and lungs to help them breathe on both land and water.
(4) True. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our respiratory systems. That is why mountaineers carry oxygen with them.
(5) True. Muscle cells break down glucose into lactic acid with the release of energy in the absence oxygen during heavy activities. This process is called anaerobic respiration.
