What are enzymes? Name any one enzyme of our digestive system and write its function.
Enzymes are biological catalysts. Catalysts are proteins that increase the rate of chemical reactions without being used up. For example: Amylase catalyses the breakdown of starch into sugars in the mouth and small intestine.
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
State the three common features of all the respiratory organs like skin, gills and lungs.
(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 ?
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).
Write correct sequence of four steps of method for the preparation of temporary mount of a stained leaf peel.
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) Define a nutrient. Name four important nutrients present in our food.
(b) What are the various types of heterotrophic nutrition ?
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.
(a) What is photosynthesis ?
(b) Write a chemical equation to show the process of photosynthesis in plants.
(c) Explain the mechanism of photosynthesis.
Draw a diagram of human excretory system and label renal artery and urethra.
State in brief the function of :
List the three kinds of blood vessels of human circulatory system and write ¦ their functions in tabular form.
A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :
Name the intermediate and the end products of glucose breakdown in aerobic respiration.
Name the component of blood that helps in the formation of blood clot in the event of a cut.
(a) What is meant by breathing? What happens to the rate of breathing during vigorous exercise and why?
(b) Define translocation with respect to transport in plants. Why is it essential for plants? Where in plants are the following synthesised?
(i) Sugar (iii) Hormone
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 ?
What is the scientific name of the animals which are :
(i) only meat eaters ?
(ii) only plant eaters ?
(iii) both, plant and meat eaters ?
(a) What criteria can be used to decide whether something is alive ?
(b) What is meant by life processes ? Name the basic life processes common to all living organisms which are essential for maintaining life.
(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 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) 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.
Name the process by which plant parts like roots, stems, and leaves get oxygen required for respiration.
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.
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…………..
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.