What happens to visible light of the Sun when it falls on chlorophyll?
Visible light of the Sun consists of seven colours, namely, violet, indigo, blue, green, yellow, orange and red. Out of these lights of different wave lengths, chlorophyll absorbs mainly blue, violet, red and orange lights but does not absorb the green light. It is due to the reflection of green light by the chlorophyll that the plant looks green in colour.
(a) Which part of the body secretes bile ? Where is bile stored ? What is the function of bile ?
(b) What is trypsin ? What is its function ?
Name the following :
(a) The process in plants which converts light energy into chemical energy.
(b) Organisms that cannot prepare their own food.
(c) Organisms that can prepare their own food.
(d) The cell organelle where photosynthesis occurs.
(e) The cells which surround a stomatal pore.
(f) An enzyme secreted by gastric glands in stomach which acts on proteins.
Apart from sunlight and chlorophyll, what other things are required to make food by photosynthesis ?
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
Out of photosynthesis and respiration in plants, which process occurs :
(a) all the time ?
(b) only at daytime ?
State whether the following statements are true or false :
(a) During respiration, the plants take C02 and release 02.
(b) Energy can be produced in cells without oxygen.
(c) Fish and earthworm exchange gases during respiration in the same way.
What are the different ways in which glucose is oxidised to provide energy in various organisms ? Give one example of each.
Explain why, when air is taken in and let out during breathing, the lungs always contain a residual volume of air.
State the three common features of all the respiratory organs like skin, gills and lungs.
Give two points of differences between respiration in plants and respiration in animals.
A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :
(a) What are autotrophs ? Give one example of autotrophs.
(b) What are the conditions necessary for autotrophic nutrition ?
(a) Photosynthesis converts energy X into energy Y. What are X and Y ?
(b) State the various steps involved in the process of photosynthesis.
a) How do plants obtain food ?
(b) Why do plants need nitrogen ? How do plants obtain nitrogen ?
(a) Leaves of a healthy potted plant were coated with vaseline. Will this plant remain healthy for long ? Give reason for your answer.
(b) What will happen to the rate of photosynthesis in a plant under the following circumstances ?
(a) Name the main organs of the human digestive system. Also name the associated glands.
(b) How do carbohydrates, fats and proteins get digested in human beings ?
Name the areas in a woody stem through which respiratory exchange of gases takes place.
Fill in the following blanks with suitable words :
(a) The organs of respiration in man are the…………..
(b) The actual exchange of gases takes place in the………… of the lungs.
(c) ………………in the lungs provide a very large surface area for gaseous exchange.
(d) Yeast undergoes……….. respiration whereas Amoeba undergoes………….. respiration.
(e) Gills are the breathing organs in…………..
(a) Explain how, the air we breathe in gets cleaned while passing through the nasal passage.
(b) Why do the walls of trachea not collapse when there is less air in it ?
(c) How are oxygen and carbon dioxide exchanged in our body during respiration ?
(d) How are lungs designed in human beings to maximise the exchange of gases ?