(a)Explain how does the exchange of gases occur in plants across the surface of stems, roots and leaves.
(b) How are water and minerals transported in plants ?
(a) In plants there are tiny pores called stomata on leaves and lenticels in stem which facilitate the exchange of gases. Carbon dioxide is taken in and oxygen given out {during photosynthesis} and vice versa during respiration.
(b) Water and minerals are transported within the plant by the Xylem vessels (mainly in an upward direction); these are part of the vascular system which also includes Phloem vessels.
Phloem transports the products of photosynthesis within the plant, to all parts like the stem, roots, fruits etc. in all directions.
What are the different ways in which glucose is oxidised to provide energy in various organisms ? Give one example of each.
Define (i) saprophytic nutrition (ii) parasitic nutrition, and (iii) holozoic nutrition. Give one example of each type.
(a) Photosynthesis converts energy X into energy Y. What are X and Y ?
(b) State the various steps involved in the process of photosynthesis.
State the three common features of all the respiratory organs like skin, gills and lungs.
Name the correct substrates for the following enzymes
(a) Trypsin (b) Amylase (c) Pepsin (d) Lipase
State the role of the following in human digestive system :
(i) Digestive enzymes (ii) Hydrochloric acid (iii) Villi
Name the intermediate and the end products of glucose breakdown in aerobic respiration.
Which of the following type of energy is used by living organisms to perform vital life processes ?
Kinetic energy, Chemical energy, Potential energy, Nuclear energy
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) How does carbon dioxide from the air enter the leaves of a plant to be used in photosynthesis ?
(b) How does water from the soil reach the leaves of a plant to be used in photosynthesis ?
Name the substance whose build up in the muscles during vigorous physical exercise may cause cramps.
Name the areas in a woody stem through which respiratory exchange of gases takes place.
a) Leaves of a healthy potted plant were coated with vaseline to block the stomata. Will this plant remain healthy for long? State three reasons for your answer.
(b) State any two differences between autotrophic nutrition and heterotrophic nutrition.
In the experiment "Light is essential for photosynthesis", why does the uncovered part of the leaf turn blue-black after putting iodine solution?
Fill in the following blanks with suitable words :
(a) All green plants are…………..
(b) All non-green plants and animals are…………
(c) Heterotrophs depend on…….. and other……………… for food,
(d) Green plants use……… ,………… and………… to make food.
(e) Iodine turns blue-black on reacting with………………
(a) What would happen if all the green plants disappear from the earth ?
(b) If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring ? Justify your answer.
In mammals and birds why is it necessary to separate oxygenated and de-oxygenated blood ?
(a) Draw a diagram of excretory system in human beings and label the following parts. Aorta, kidney, urinary bladder and urethra.
(b) How is urine produced and eliminated ?
In human alimentary canal, name the site of complete digestion of various components of food. Explain the process of digestion.
(a) Draw a diagram of human respiratory system and label the following:
(i) part where air is filtered by fine hair and mucus
(ii) part which terminates in balloon – like structures
(iii) balloon – like structures where exchange of gases takes place. (iv) part which separates chest cavity from abdominal cavity.
(b) Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms?
(a) Draw a sectional view of the human heart and label on it – Aorta, Right ventricle and Pulmonary veins.
(b) State the functions of the following components of transport system:
(i) Blood (ii) Lymph
Name the green dot like structures in some cells observed by a student when a leaf peel was viewed under a microscope. What is this green colour due to?
A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :