(a) How do guard cells regulate opening and closing of stomatal pores ?
(b) Two similar green plants are kept separately in oxygen free containers, one in dark and the other in continuous light. Which one will live longer ? Give reasons.
(a) The opening and closing of stomatal pores is controlled by the guard cells, when water flows into the guard cells, they swell, become curved and cause the pore to open whereas when the guard cells lose water, they shrink, become straight and close the stomatal pore. (b) Plant kept in continuous light will live longer because it will be able to produce oxygen required for its respiration by the process of photosynthesis.
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
Write correct sequence of four steps of method for the preparation of temporary mount of a stained leaf peel.
A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :
Name the final product/products obtained in the anaerobic respiration, if it takes place :
(a) in a plant (like yeast).
(b) in an animal tissue (like muscles).
List the three kinds of blood vessels of human circulatory system and write ¦ their functions in tabular form.
Name the component of blood that helps in the formation of blood clot in the event of a cut.
Apart from sunlight and chlorophyll, what other things are required to make food by photosynthesis ?
(a) Name the pigment in leaves which absorbs sunlight energy.
(b) What is the colour of this pigment ?
(a) Define a nutrient. Name four important nutrients present in our food.
(b) What are the various types of heterotrophic nutrition ?
Name the process by which plant parts like roots, stems, and leaves get oxygen required for respiration.
Name the type of respiration in which the end products are :
(a) C2H,OH and C02
(b) C02 and H20
(c) Lactic acid
Give one example of each case where such a respiration can occur.
State the three common features of all the respiratory organs like skin, gills and lungs.
Name the intermediate and the end products of glucose breakdown in aerobic respiration.
(a) List the three events that occur during the process of photosynthesis.
Explain the role of stomata in this process.
(b) Describe an experiment to show that "sunlight is essential for photosynthesis."
The leaves of a plant first prepare food A by photosynthesis. Food A then gets converted into food What are A and B ?
All the animals can be divided into three groups on the basis of their eating habits. Name the three groups.
What is the scientific name of the animals which are :
(i) only meat eaters ?
(ii) only plant eaters ?
(iii) both, plant and meat eaters ?
Arrange the following processes involved in the nutrition in animals in the correct order (in which they take place):
Assimilation, Egestion, Ingestion, Absorption, Digestion
(a) What is common for Cuscuta, ticks and leeches ?
(b) Name the substances on which the following enzymes act in the human digestive system :
(i) Trypsin (ii) Amylase (iii) Pepsin (iv) Lipase
(c) Why does absorption of digested food occur mainly in the small intestine ?
(a) What is photosynthesis ?
(b) Write a chemical equation to show the process of photosynthesis in plants.
(c) Explain the mechanism of photosynthesis.
(a) Define nutrition. Why is nutrition necessary for an organism ?
(b) What are the different modes of nutrition ? Explain with one example of each mode of nutrition.
(c) Name the mode of nutrition in (i) roundworm, and (ii) Plasmodium.
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 differences between aerobic and anaerobic respiration ? Name some organisms that use anaerobic mode of respiration.