Question

1) Write the events in photosynthesis. How is it different in desert plants? (2 marks)
2) Explain the difference between autotrophs and heterotrophs (2 marks)
3) From where do aquatic, terrestrial and submerged aquatic plants obtain the raw materials for photosynthesis? (2 marks)
4) What would happen: (2 marks)
a) If the intensity of light is more?
b) If the pollution is more?
5) How will be release of carbon dioxide in day and night time? (2 marks)

Answer 1

Answer:

1) In desert plants, the stomata is open during night. During night, desert plants absorb carbon dioxide and form an intermediate. Then during day time when the stomata is closed to prevent loss of water, they use this stored carbon dioxide to perform photosynthesis.

2) Autotrophs are known as producers because they are able to make their own food from raw materials and energy. Examples include plants, algae, and some types of bacteria. Heterotrophs are known as consumers because they consume producers or other consumers. Dogs, birds, fish, and humans are all examples of heterotrophs.

3) The raw materials for photosynthesis are carbondioxide and water. Terrestrial plants get carbondioxide from environment and water from thesoil. Aquatic plants obtain Co2 that is present indissolved form in water. Water is simply absorbed by the parts of plant submerged in water.

4)

a) For each single photon at the same frequency. From the point of view of photons, a more intense light is not made of "higher waves", but of a higher number of photons. Than is obvious that, if each photon is capable to expel an electron, the more intense is the light the more number of electrons will be expelled.

b) Long-term health effects from air pollution include heart disease, lung cancer, and respiratory diseases such as emphysema. Air pollution can also cause long-term damage to people's nerves, brain, kidneys, liver, and other organs. Some scientists suspect air pollutants cause birth defects.

5)as global temperatures rise, scientists say the output of carbon dioxide by plants will accelerate. During daylight hours, plants take in carbon dioxide and release oxygen through photosynthesis, and at night only about half that carbon is then released through respiration.