Advertisements
Advertisements
प्रश्न
Advertisements
उत्तर
Carbon dioxide is removed from the atmosphere by:
(i) Producers - Producers or green plants use carbon dioxide through photosynthesis. A small amount of carbon dioxide is used by chemosynthetic bacteria also.
(ii) Marine Organisms - Some amount of carbon dioxide is directly fixed by a few marine organisms and sea water absorbs carbon dioxide in the form of dissolved carbon dioxide, carbonic acid, carbonate and bicarbonates.
APPEARS IN
संबंधित प्रश्न
Fill in the blank:
Land plants obtain their carbon dioxide from the ______.
The diagram alongside refers to an experiment in which the apparatus was set up with the light source 10 cm away from the plant. After 15 minutes the number of bubbles evolved per minute from the cut stem was recorded. The light source was moved to 20 cm away from the plant, left for 15 minutes and the number of bubbles evolved per minute was again recorded. The experiment was repeated with the light source at distances of 40, 60, 80 and 100 cm away from the plant. Plot a graph for the results obtained and answer the following questions.
(i) From the graph it seems likely that the rate of bubbling per minute at 50 cm would have been
(a) 2.0 (b) 2.5 (c) 3.0 (d) 3.5
(ii) The gas produced by the plant during the experiment was
(a) air (b) oxygen (c) carbon dioxide (d) nitrogen (e) hydrogen
(iii) The gas collected comes due to the breakdown of
(a) glucose (b) starch (c) water (d) air (e) ATP
(iv) If ice cubes were added to the water, the rate of bubble formation would
(a) Stay the same.
(b) Increase because more water is added.
(c) Decrease because the temperature drops.
(d) Decrease because water freezes.
(e) Cannot tell from the information given.
(v) If some sodium bicarbonate is added to the water the rate of bubble formation
(a) Increases because more respiration occurs.
(b) Increases because more photosynthesis occurs.
(c) Increases because the gas becomes less soluble.
(d) Decreases because carbon dioxide acts as a limiting factor.
(e) Decreases because respiration decreases.
The chemical substance used to test the presence of starch in the cell of a leaf is ______.
Given below is the representation of a certain phenomenon in nature. With four organisms 1-4.
Name any one organism that could be shown at No .5
Given below is the representation of a certain phenomenon in nature. With four organisms 1-4.
Name one natural element which all the organisms 2-4 and even 5 are getting from No. 1 for their survival.
The diagram below shows two test-tubes A and B. Test-tube A contains a green water plant. Test-tube B contains both a green water plant and a snail. Both test-tubes are kept in sunlight. Answer the questions that follow:
(a) Name the physiological process that releases the bubbles of oxygen.
(b) Explain the physiological process as mentioned above in (a).
(c) What is the purpose of keeping a snail in test-tube B?
(d) Why does test-tube B have more bubbles of oxygen?
(e) Give an example of a water plant that can be used in the above experiment.
(f) Write the overall chemical equation for the above process.
Chlorophyll is necessary for photosynthesis.
Complete the following sentence with appropriate word:
A light-induced reaction which leads to the splitting of water is _____ of water.
Give reasons/explain:
During the starch test, the leaf is boiled in water.
Give reasons/explain:
During the starch test, the leaf is boiled in methylated spirit.
