1. 1.Name the product and by product of photosynthesis.
2.In which biochemical form the photosynthate moves in phloem tissue?
3.What are the raw materials of photosynthesis?
4.What is the similarity between chlorophyll and hemoglobin?
5.Name the products of photolysis of water.
6.What are the end products of light dependant reaction?
7.Which cell organelle is the site of photosynthesis?
8.What is the difference between digestion of heterotrophs and saprotrophs?
9.Give example of two plants and two animal parasites.
10.Name the enzyme present in saliva, what is its role in digestion?
11.Which chemical is used to test for starch? Which colour shows the presence of starch?
12.Give the term- rhythmic contraction of alimentary canal muscle to propel food.
13.Name the three secretions of gastric glands.
14.What is the function of mucus in gastric gland?
15.Name the sphincter which regulates the exit of food from the stomach.
16.Give the functions of hydrochloric acid for the body.
17.What is the role of pepsin in stomach?
18.Why pancreas is called mixed gland?
19.Give two functions of bile juice, from which organ it is released?
20.Name the largest gland of our body.
21.Name any three important enzymes of pancreas and the food component on which they act.
22.Where from intestinal juice come to the small intestine?
23.What is the function of intestinal juice?
24.What are the simplest digestive product of carbohydrate, fats and protein?
2.In which biochemical form the photosynthate moves in phloem tissue?
3.What are the raw materials of photosynthesis?
4.What is the similarity between chlorophyll and hemoglobin?
5.Name the products of photolysis of water.
6.What are the end products of light dependant reaction?
7.Which cell organelle is the site of photosynthesis?
8.What is the difference between digestion of heterotrophs and saprotrophs?
9.Give example of two plants and two animal parasites.
10.Name the enzyme present in saliva, what is its role in digestion?
11.Which chemical is used to test for starch? Which colour shows the presence of starch?
12.Give the term- rhythmic contraction of alimentary canal muscle to propel food.
13.Name the three secretions of gastric glands.
14.What is the function of mucus in gastric gland?
15.Name the sphincter which regulates the exit of food from the stomach.
16.Give the functions of hydrochloric acid for the body.
17.What is the role of pepsin in stomach?
18.Why pancreas is called mixed gland?
19.Give two functions of bile juice, from which organ it is released?
20.Name the largest gland of our body.
21.Name any three important enzymes of pancreas and the food component on which they act.
22.Where from intestinal juice come to the small intestine?
23.What is the function of intestinal juice?
24.What are the simplest digestive product of carbohydrate, fats and protein?
25.Name the finger like projections of small intestine and what is the necessity of such type of projections in digestive system?
26.Why are intestinal villis highly vascular?
27.What is the function of anal sphincter?
28.Name the site of anaerobic and aerobic respiration in a cell.
29.A three carbon compound is the common product of both aerobic and anaerobic pathway. What is that?
30.Why do we get muscle cramp after vigorous exercise?
31.Distinguish between lactic acid and alcoholic fermentation?
32.Name the energy currency molecule of cell?
33.The breathing rate of aquatic animals is high, why?
34.What is the function of mucus and fine hair in nostrils?
35.Give the function of network of capillaries on alveoli.
36.Name the main carrier of oxygen and carbon dioxide in man.
37.Why does haemoglobin molecule act as efficient carrier of oxygen than diffusion process?
38.Give example of any three substances transported by plasma.
39.Name the organ that- (a) pushes blood around body (b) make blood to reach to tissues.
40.Name the blood vessel that carries blood from heart to lungs and from lungs to heart.
41.How many heart chambers are there in (a) fish (b) frog (c) lizard (d) crocodile (e) birds (f) man?
42.Name the device that measures blood pressure.
43.What is the normal blood pressure of man?
44.Why capillaries are thin walled?
45.Which cell of blood help in wound healing?
46.What is the other name of lymph?
47.Give two function of lymph.
48.What is the direction of flow of water in xylem and food in phloem?
49.Why do plants need less energy than animals?
50.Which process acts as suction to pull water from xylem cells of roots.
51.Mention two functions of transpiration.
52.What are the two substances transported through phloem tissue?
26.Why are intestinal villis highly vascular?
27.What is the function of anal sphincter?
28.Name the site of anaerobic and aerobic respiration in a cell.
29.A three carbon compound is the common product of both aerobic and anaerobic pathway. What is that?
30.Why do we get muscle cramp after vigorous exercise?
31.Distinguish between lactic acid and alcoholic fermentation?
32.Name the energy currency molecule of cell?
33.The breathing rate of aquatic animals is high, why?
34.What is the function of mucus and fine hair in nostrils?
35.Give the function of network of capillaries on alveoli.
36.Name the main carrier of oxygen and carbon dioxide in man.
37.Why does haemoglobin molecule act as efficient carrier of oxygen than diffusion process?
38.Give example of any three substances transported by plasma.
39.Name the organ that- (a) pushes blood around body (b) make blood to reach to tissues.
40.Name the blood vessel that carries blood from heart to lungs and from lungs to heart.
41.How many heart chambers are there in (a) fish (b) frog (c) lizard (d) crocodile (e) birds (f) man?
42.Name the device that measures blood pressure.
43.What is the normal blood pressure of man?
44.Why capillaries are thin walled?
45.Which cell of blood help in wound healing?
46.What is the other name of lymph?
47.Give two function of lymph.
48.What is the direction of flow of water in xylem and food in phloem?
49.Why do plants need less energy than animals?
50.Which process acts as suction to pull water from xylem cells of roots.
51.Mention two functions of transpiration.
52.What are the two substances transported through phloem tissue?
53.Name the food component whose digestion produce nitrogenous waste?
54.Which is the functional unit of kidney?
55.What is the cup shaped structure of nephron called?
56.Which materials are selectively reabsorbed by nephron tubule?
57.What are the two important functions of kidney.
58.What is the other name of artificial kidney?
54.Which is the functional unit of kidney?
55.What is the cup shaped structure of nephron called?
56.Which materials are selectively reabsorbed by nephron tubule?
57.What are the two important functions of kidney.
58.What is the other name of artificial kidney?
Answers:
1.Product-starch by product-oxygen
2.Sucrose.
3.carbon dioxide, water
4.both are pigments
5.oxygen, electron and protons
6.ATP, NADPH2
7.chloroplast
8.Heterotrophs- digestion occurs inside the body, saprotrophs- digestion occurs outside of body.
9.plant-cuscuta, orchid animal-lice, tics
10.Salivary amylase-It digests starch to maltose.
11.Iodine solution, blue
12.Peristaltic
13.HCl, pepsin, mucus
14.Protects the inner lining of stomach from the action of acid HCl.
15.Pyloric sphincter
16.Activates pepsin, make the medium acidic for enzyme action, Microcidal.
17.Pepsin digests protein into peptones.
18.It behaves as exocrine as well as endocrine gland.
19.(i)Emulsifies fat (ii) Change the food medium into alkaline on which pancreatic enzyme can act.
20.Liver
21.(i)Amylase- carbohydrate, (ii) Lipase- fat, (iii) Trypsin- protein.
22.Secreted from internal wall of small intestine.
23.Perform final digestion of all food components.
24.(i) carbohydrate- glucose, (ii)fat- fatty acid, glycerol (iii) protein- amino acid.
25.Villi, Increase the surface area of absorption of digested food.
26.More the blood supply, the more will be the absorption of digested food.
27.Regulate the exit of waste material.
28.Anaerobic-cytoplasm, aerobic- mitochondria.
29.Pyruvic acid.
30.Because of the accumulation of lactic acid which is formed due to anaerobic break down of glucose.
31.Lactic acid is a 3 carbon compound produced on oxidation of glucose anaerobically where as ethanol a 2 carbon compound is formed on anaerobic oxidation of glucose along with co2.
32.ATP
33.Because they take dissolved oxygen whose percentage in water is lower than atmospheric percentage.
34.Filter impurities.
35.Exchange of gases by diffusion process. Oxygen from lungs moves to blood and carbon dioxide from blood moves to lungs.
36.O2(-ve)haemoglobin, O2(-ve)plasma.
37.Haemoglobin has high affinity for oxygen, so it carries the gas faster in blood where as diffusion is a slow process.
38.Digested food, carbon dioxide, nitrogenous waste.
39.(a) Heart, (b) blood vessel.
40.(a) Pulmonary artery, (b) pulmonary vein.
41.(a) 2, (b) 3, (c) 3, (d) 4 (e) 4 (f) 4.
42.Sphygmomanometer
43.120/80
44.For exchange of materials by diffusion process.
45.Platelet cells.
46.Tissue fluid.
47.Carries digested and absorbed fats, drains excess fluid from extra cellular space to blood.
48.Flow of water is unidirectional i.e. from root to leaves, but flow of food bidirectional i.e. leaf to sink and vice versa.
49.Plants are nonmotile; most of the cells are dead.
50.Transpiration.
51.(i)Absorption and upward movement of water and minerals, (ii) temperature regulation.
52.Sucrose, amino acid.
53.Protein, nucleic acid.
54.Nephron.
55.Bowman’s capsule.
56.Glucose, amino acids, salts, water.
57.Filtration of nitrogenous waste from blood and osmoregulation.
58.Dialysis.
2.Sucrose.
3.carbon dioxide, water
4.both are pigments
5.oxygen, electron and protons
6.ATP, NADPH2
7.chloroplast
8.Heterotrophs- digestion occurs inside the body, saprotrophs- digestion occurs outside of body.
9.plant-cuscuta, orchid animal-lice, tics
10.Salivary amylase-It digests starch to maltose.
11.Iodine solution, blue
12.Peristaltic
13.HCl, pepsin, mucus
14.Protects the inner lining of stomach from the action of acid HCl.
15.Pyloric sphincter
16.Activates pepsin, make the medium acidic for enzyme action, Microcidal.
17.Pepsin digests protein into peptones.
18.It behaves as exocrine as well as endocrine gland.
19.(i)Emulsifies fat (ii) Change the food medium into alkaline on which pancreatic enzyme can act.
20.Liver
21.(i)Amylase- carbohydrate, (ii) Lipase- fat, (iii) Trypsin- protein.
22.Secreted from internal wall of small intestine.
23.Perform final digestion of all food components.
24.(i) carbohydrate- glucose, (ii)fat- fatty acid, glycerol (iii) protein- amino acid.
25.Villi, Increase the surface area of absorption of digested food.
26.More the blood supply, the more will be the absorption of digested food.
27.Regulate the exit of waste material.
28.Anaerobic-cytoplasm, aerobic- mitochondria.
29.Pyruvic acid.
30.Because of the accumulation of lactic acid which is formed due to anaerobic break down of glucose.
31.Lactic acid is a 3 carbon compound produced on oxidation of glucose anaerobically where as ethanol a 2 carbon compound is formed on anaerobic oxidation of glucose along with co2.
32.ATP
33.Because they take dissolved oxygen whose percentage in water is lower than atmospheric percentage.
34.Filter impurities.
35.Exchange of gases by diffusion process. Oxygen from lungs moves to blood and carbon dioxide from blood moves to lungs.
36.O2(-ve)haemoglobin, O2(-ve)plasma.
37.Haemoglobin has high affinity for oxygen, so it carries the gas faster in blood where as diffusion is a slow process.
38.Digested food, carbon dioxide, nitrogenous waste.
39.(a) Heart, (b) blood vessel.
40.(a) Pulmonary artery, (b) pulmonary vein.
41.(a) 2, (b) 3, (c) 3, (d) 4 (e) 4 (f) 4.
42.Sphygmomanometer
43.120/80
44.For exchange of materials by diffusion process.
45.Platelet cells.
46.Tissue fluid.
47.Carries digested and absorbed fats, drains excess fluid from extra cellular space to blood.
48.Flow of water is unidirectional i.e. from root to leaves, but flow of food bidirectional i.e. leaf to sink and vice versa.
49.Plants are nonmotile; most of the cells are dead.
50.Transpiration.
51.(i)Absorption and upward movement of water and minerals, (ii) temperature regulation.
52.Sucrose, amino acid.
53.Protein, nucleic acid.
54.Nephron.
55.Bowman’s capsule.
56.Glucose, amino acids, salts, water.
57.Filtration of nitrogenous waste from blood and osmoregulation.
58.Dialysis.
2. 1. A farmer floods his field everyday thinking that watering in this manner will result a better yield of his wheat crop. What will be the result of this action of the farmer.
Ans.This will result in water logging of the soil due to which roots cannot breathe and ultimately plants will die .
2. Name the term for transport of food from leaves to other parts of plants.
Ans.Translocation
3. Which pancreatic enzyme is effective in digesting proteins?
Ans.Trypsin
4. Which enzyme is present in saliva breaks down starch?
Ans.Salivary amylase.
5. After a vigorous exercise you may experience cramps in your leg muscles. Why does this happen?
Ans.Accumulation of lactic acid.
6. Name the organelle in which photosynthesis occurs.
Ans.Chloroplast.
7. Name the type of blood vessels which carry blood from organs to the heart.
Ans.Veins.
8. Name the respiratory structures of i.Mosquito ii)earth worm.
Ans.(i) mosquito—System of air tubes. (ii)earth worm—moist skin.
9. Write the two functions of kidneys.
Ans.Osmoregulation and excretion.
10. What are spiracles.
Ans The holes found on the lateral side of insect‘s body.
Ans.This will result in water logging of the soil due to which roots cannot breathe and ultimately plants will die .
2. Name the term for transport of food from leaves to other parts of plants.
Ans.Translocation
3. Which pancreatic enzyme is effective in digesting proteins?
Ans.Trypsin
4. Which enzyme is present in saliva breaks down starch?
Ans.Salivary amylase.
5. After a vigorous exercise you may experience cramps in your leg muscles. Why does this happen?
Ans.Accumulation of lactic acid.
6. Name the organelle in which photosynthesis occurs.
Ans.Chloroplast.
7. Name the type of blood vessels which carry blood from organs to the heart.
Ans.Veins.
8. Name the respiratory structures of i.Mosquito ii)earth worm.
Ans.(i) mosquito—System of air tubes. (ii)earth worm—moist skin.
9. Write the two functions of kidneys.
Ans.Osmoregulation and excretion.
10. What are spiracles.
Ans The holes found on the lateral side of insect‘s body.
3. What are the raw materials for photosynthesis? (1 mark)
Answer: The raw materials and other necessary items required for photosynthesis are Sunlight, Water, CO2and Chlorophyll.
4. What is the role of bile juice in digestion? (1 mark)
Answer: Bile is alkaline in nature and it is temporarily stored in gall bladder and helps in digestion of fats,
it also helps in absorption fats.
5. Write the equation for respiration? (1 mark)
Answer:
Glycol sis
|
In presene of O2
| |||||
C6H12O6
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-->
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C3H4O3
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------->
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6CO2 +
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6H2O +
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38ATP
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Pyuvic acid
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Kreb cycle in mitochondria
|
6. Name three types of blood vessels used in the transport of blood. (1 mark)
Answer: Arteries, vein and capillaries
Note: There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart.
7. Name the artificial method for the removal of liquid nitrogenous waste from body? (1 mark)
Answer: Dialysis: Dialysis is a process by which waste materials and excess water are removed from the blood. This is a normal function of our kidneys inside the body.
8. Write any two points of difference respiration in plants and respiration in animals. (2 marks)
Answer:
Respiration in plants.
|
Respiration in animals
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1.In plants separate respiratory organs are absent
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1.In animals respiratory organs are generally present
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2.The rate of respiration is slow.
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2.The rate of respiration is fast.
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3.They lack respiratory surface
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3. Respiratory surface is generally present.
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9. How are the alveoli designed to maximize the exchange of gases? (2 marks)
Answer: The alveoli are present at the terminal of bronchioles. They are balloon shaped structures which increases the surface area for the exchange of gases and are richly supplied with blood vessels to take the oxygen to different cells
10. Amylase is secreted by two different glands. Name them. Write is the action of amylase on food? (2 marks)
Answer: Salivary glands are found in mouth cavity .They secrete enzyme called salivary amylase or ptyalin. It helps in digestion of starch.
Pancreas secrets pancreatic juice into small intestine. Pancreatic juice contains tyrosine and pancreatic amylase.
Pancreatic amylase is a major digestive enzyme, which can hydrolyze starch into simplersugars, like maltose and glucose, for absorption.
11. Name the passage in sequence through which urine passes from kidneys to the outside in humans. How is urine prevented from flowing back into the ureters? (2 marks)
Answer:
kidney -> the urinary bladder -> the urethra ----> outside [via vaginal opening in women or via the penis in man]
There are valves present in ureters called as ureterovesical valves which prevent the backflow of urine.
12. State the role of the following in the human respiratory system
(a) Nasal cavity (ii) Diaphragm (iii) Alveoli (3 marks)
Answer: (i) Nasal cavity: It contains hair and mucus which entrap the dust particles.
(b) Diaphragm: Contract and relax to increase and decrease the volume of chest cavity respectively
(c) Alveoli: it helps in exchange of air in blood. it transfer oxygen to the blood and takes carbon di oxide from the blood.
13. Give reasons for the following:
(i)The glottis is guarded by epiglottis.
(ii) The lung alveoli are covered with blood capillaries.
(iii) The wall of trachea is supported by cartilage rings. (3 marks)
Answer : (i) The epiglottis guards the entrance of the glottis and prevent flow of food into wind pipe.
(ii) Lungs alveoli are covered with blood capillaries for the exchange of gases to take place and oxygen can easily diffuse into the blood stream and be transported to various parts of the body through the heart.
(iii) The wall of trachea is supported by cartilage rings which percent them to collapse when air is absent in them
14. 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. (3 marks)
Answer: By applying Vaseline on leaves stomata gets covered and transpiration stops. This prevents loss of water vapour and the moisture of the leaf retain for sometimes. But as the layer of vaselin stops all type of gaseous exchange, leaf will end up dying.
(a) Respiration will stop. (b) Transpiration will stop. (c) Photosynthesis will stop.
15. What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration. (3 marks)
Answer :
Aerobic
|
Anaerobic
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(i) It occurs in all living cells of higher plants.
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It occurs in bacteria, certain fungi, germinatin seeds and fleshy fruits muscles.
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(ii) It requires oxygen.
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Oxygen in not required
|
(iii) The end products are CO2 and H2O.
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The end products are alcohol [fungi] or lactic acid [ muscles] and CO2.
|
(iv) The oxidation of one molecules of glucose produces 38 ATP molecules
|
The number of ATP molecules produced is only 2.
|
some organisms that use the anaerobic mode of respiration : bacteria, certain fungi, germinatin seeds and fleshy fruits muscles
| |
16. Describe double circulation in human beings. Why is it necessary? (3 marks)
Answer :The blood passes to aorta from the left ventricle. The aorta gives rise to manyarteries that distribute the oxygenated blood to all the regions of the body. Therefore, the blood goes twice through the heart. This is known as double circulation.
Importance of double circulation:: This separate oxygenated and deoxygenated blood that ensure more efficient supply of oxygen to the body cells. This also help in maintaining a constant internal temperature and allows mammals and birds to carry-out body processes more efficiently.
17. (i) Name the blood vessel that brings oxygenated blood to the human heart. (5 marks)
(ii) Which chamber of human heart receives oxygenated blood?
(iii) Explain how oxygenated blood from this chamber is sent to all parts of the body.
Ans: (i) The pulmonary vein (ii) the left atrium
18. Name any three waste products of plants? (1 mark)
Ans: The gums, resins and latexes
Ans: The gums, resins and latexes
19. Name three excretory organs of man. (1 mark)
Ans: lungs, kidney and skin
Ans: lungs, kidney and skin
20. Name the part of plants which helps in transportation. (1 mark)
Ans: Phloem tissue
Ans: Phloem tissue
21. Name the juice secreted by the liver. (1 mark)
Ans: Bile
Ans: Bile
22. What is the function of digestive enzymes? (2 marks)
Ans: Digestive enzymes such as amylase, lipase, pepsin, trypsin, etc. help in the breaking down of complex food particles into simple ones. These simple particles can be easily absorbed by the blood and thus transported to all the cells of the body.
Ans: Digestive enzymes such as amylase, lipase, pepsin, trypsin, etc. help in the breaking down of complex food particles into simple ones. These simple particles can be easily absorbed by the blood and thus transported to all the cells of the body.
23. What is the role of saliva in the digestion of food? (2 marks)
Ans: The salivary glands secrete the first of the digestive juices, the saliva. In the digestion process, the saliva helps the teeth and tongue to masticate and mix up the food thoroughly. Mucus in saliva helps in lubricating and adhering food particles into a bolus. Then the bolusconveyed to pharynx for further digestion. Lysosomes present in saliva acts as anantibacterial agent that prevents infection.
Ans: The salivary glands secrete the first of the digestive juices, the saliva. In the digestion process, the saliva helps the teeth and tongue to masticate and mix up the food thoroughly. Mucus in saliva helps in lubricating and adhering food particles into a bolus. Then the bolusconveyed to pharynx for further digestion. Lysosomes present in saliva acts as anantibacterial agent that prevents infection.
24. Point out two differences between an artery and a vein. (2 marks)
Ans: Artery
Ans: Artery
a. Vessels which carry blood from the heart to various body parts
b. Arteries carry oxygenated blood from the heart except pulmonary artery
Vein
c. Vessels which carry blood from the various body parts to the heart
d. Veins carry deoxygenated blood from the various body parts except pulmonary vein
25. What do you mean by double circulation of blood? (2 marks)
Ans: The human heart is divided into four chambers − the right atrium, the right ventricle, the left atrium, and the left ventricle.
Ans: The human heart is divided into four chambers − the right atrium, the right ventricle, the left atrium, and the left ventricle.
Flow of blood in the heart :
· The heart has superior and inferior vena cava, which carries de-oxygenated blood from the upper and lower regions of the body respectively and supplies this de-oxygenated blood to the right atrium of the heart.
Flow of blood in the human heart
· The right atrium then contracts and passes the de-oxygenated blood to the right ventricle, through an auriculo-ventricular aperture.
· Then the right ventricle contracts and passes the de-oxygenated blood into the two pulmonary arteries, which pumps it to the lungs where the blood becomes oxygenated. From the lungs, the pulmonary veins transport the oxygenated blood to the left atrium of the heart.
· Then the left atrium contracts and through the auriculo-ventricular aperture, the oxygenated blood enters the left ventricle.
· The blood passes to aorta from the left ventricle. The aorta gives rise to many arteries that distribute the oxygenated blood to all the regions of the body.
Therefore, the blood goes twice through the heart. This is known as double circulation
26. Write any two points of difference between respiration in plants and animals? (2 marks)
Ans: Respiration in plants.
Ans: Respiration in plants.
a) In plants separate respiratory organs are absent
b) The rate of respiration is slow.
c) They lack respiratory surface
Respiration in animals
d) In animals respiratory organs are generally present
e) The rate of respiration is fast.
f) Respiratory surface is generally present.
27. What criteria do we use to decide whether something is alive? (3 marks)
Ans: The main criteria to check for life, is the sign of breathing and respiration. If there is no sign of breathing or respirations then the given organism is not alive.
Ans: The main criteria to check for life, is the sign of breathing and respiration. If there is no sign of breathing or respirations then the given organism is not alive.
28. What are the differences between autotrophic nutrition and heterotrophic nutrition? (3 marks)
29. Ans:
Autotrophic nutrition
|
Heterotrophic nutrition
|
Food is synthesized from simple inorganic raw materials such as CO 2 and water.
|
Food is obtained directly or indirectly from autotrophs. This food is broken down with the help of enzymes.
|
Presence of green pigment (chlorophyll) is necessary.
|
No pigment is required in this type of nutrition.
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Food is generally prepared during day time.
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Food can be prepared at all times.
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All green plants and some bacteria have this type of nutrition.
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All animals and fungi have this type of nutrition.
|
30. Where do plants get each of the raw materials required for photosynthesis? (3 marks)
Ans:
Ans:
the raw materials for photosynthesis
| |
Water
|
Ground water
|
Sunlight
|
sun
|
CO2
|
Atmosphere
|
31. What are the different ways in which glucose is oxidized to provide energy in various organism? (3 marks)
Ans: At first glucose (6 carbon molecules) is broken in the cytoplasm of cells of all organisms. This process yields a three carbon molecule compound called pyruvate.Further break down of pyruvate takes place in different manners in different organisms.
Ans: At first glucose (6 carbon molecules) is broken in the cytoplasm of cells of all organisms. This process yields a three carbon molecule compound called pyruvate.Further break down of pyruvate takes place in different manners in different organisms.
Anaerobic Respiration
This process takes place in absence of oxygen, e.g. in yeast during fermentation. In this case pyruvate is converted into ethanol and carbon dioxide.
Aerobic Respiration
In aerobic respiration, breakdown of pyruvate takes place in presence of oxygen to give rise 3 molecules of carbon dioxide and water. The release of energy in aerobic respiration is much more than anaerobic respiration.
Lack of Oxygen
Sometimes, when there is lack of oxygen, especially during vigorous activity, in our muscles, pyruvate is converted into lactic acid (3 carbon molecule compounds). Formation of lactic acid in muscles causes cramp.
32. (i) Draw a labelled diagram of the human respiratory system. (5 marks)
(ii) How oxygen and carbon dioxide exchanged in our body during respiration?
(iii) Explain, how the air we breathe in gets cleaned while passing through the nasalpassage.
(iii) Explain, how the air we breathe in gets cleaned while passing through the nasalpassage.
Ans: (1) respiratory system
(ii) When the air enters into the lungs through nostrils, trachea and bronchi it enters into the bronchioles, from bronchioles it moves into thin walled alveolar sacs or alveoli. Alveoli are rich in blood capillaries, at this place oxygen from air diffuses into the blood and reaches to all the cells and tissues of body this oxygen now diffuses into the cell and is utilized for the oxidation of food and production of energy in mitochondria as a result of this carbon dioxide is produced in cells, due to this increased concentration of CO2, it diffuses into the blood and is brought back to alveoli and expelled out of the lungs through trachea and nostrils.
(iii) Nasal passage: This passage is separated from oral cavity by means of a hard and bony palate. It is lined by ciliated columnar epithelial cells that are rich in mucus; it brings about warming, moistening and sterilization of air. It contains hair and mucus which entrap the dust particles.
33. Point out of differences between an artery and vein. (1 mark):
Artery
Vessels which carry blood from the heart to various body parts
Arteries carry oxygenated blood from the heart except pulmonary artery
Arteries have thick elastic muscular walls
Valves are absent
Blood flows under high pressure
Vein
Vessels which carry blood from the various body parts to the heart
Veins carry deoxygenated blood from the various body parts except pulmonary vein
Veins have thin non elastic walls
Valves are present to prevent the backward flow of blood
Blood flows under low pressure
34. Write the two functions of kidneys.
Ans. Osmoregulation and excretion.
35. Name the largest artery in human body. (1 mark)
36. Ans: The largest artery in the human body is the aorta. It carries oxygenated blood to the whole body from the heart.
37. What is the difference between stroma and grana? (2 marks)
Ans:
Grana
|
Stroma
|
The stacks of thylakoids are called grana.
|
Grana are connected by intergrana or stroma thylakoids
|
Grana contribute to chloroplasts' large surface area to volume ratio.
|
It carries all the enzymes, e.g., RUBISCO, needed to carry out the "dark" reactions of photosynthesis
|
38. Write two differences between the transport of materials in xylem and phloem. (2 marks)
Ans:
Xylem
|
Phloem
|
(i) Functional xylem ells are dead.
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(i) Functional phloem cells are alive.
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(ii) It carries mineral salts, water and traces of organic molecules
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(ii) An organic solution of sugars and amino acids is
translocated.
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(iii) The movement is only upward.
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(iii) The movement can be upward or downward.
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39. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration? (2 marks)
Ans: In the aquatic habitat the concentration of oxygen is good up to a certain depth only. Moreover, as oxygen is available as dissolved in water, so taking oxygen from there is not a very efficient method to that.
In terrestrial habitat oxygen is available in free form so it is easier to absorb by organisms. This is more efficient so terrestrial organisms can facilitate better utilization of food by way of respiration.
40. Differentiate between osmoregulation and excretion?
Ans: Excretion is the elimination of metabolic waste products from the body.
Osmoregulation is regulating osmotic pressure of the body fluids by controlling the amount of water and salts in the body
41. Name any two autotrophic plants which also show heterotrophic mode of nutrition. Why do they need to do so? (2 marks)
Ans: All green plants are autotrophic but some of them also show heterotrophic nutrition like Venus fly trap and pitcher plant as their nutritional requirement is not fulfilled by photosynthesis like nitrogen and phosphorus as in some areas, the soil is deficient in nitrogen.
42. Name 3 kinds of blood vessels of human circulatory system. Write function of each. (3 marks)
Ans:
Arteries
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Veins
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Capillaries
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1.
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Carry Oxygen rich blood from heart to all parts of the body.
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Carry carbon dioxide rich blood from all parts of the body back to the heart.
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Capillaries act as a link between arteries and veins.
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2.
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Since blood flow is rapid and at high pressure they have thick elastic walls.
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They have thin walls
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Consists of just a single layer of endothelial cells.
Water and other small-molecule substances can pass through this wall.
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3.
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Valves are absent.
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Valves present to prevent back flow of blood.
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No valves are found
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43. Name the constituents of blood. Why are WBC called ‘soldiers of the body’? (3 marks)
Ans: The constituents of blood are
Red blood cells or RBCs (erythrocytes)
White blood cells or WBCs (leucocytes)
Blood platelets (thrombocytes)
WBC is called ‘soldiers of the body’ because
(a) White blood cells protect the body from infec on. If germs like bacteria or viruses enter the body, these cells surround the germs and destroy them by digesting.
(b) They also produce an bodies (blood proteins) which kill the germs and foreign particles entering our body.
44. Explain the process by which inhalation occurs during breathing in human beings. (3 marks)
Ans: he process by which oxygen rich air is taken up through the nostril into the body is known as inhalation. During inhalation, the chest cavity increases in size due to the downward movement of the diaphragm (dome shaped muscular sheet that separates chest from abdomen). As a result air from outside rushes into the lungs to fill the extra space.
Exhalation is the process by which carbon dioxide rich air comes out of the body. It occurs when the diaphragm moves up and the chest cavity becomes narrower. This creates a pressure on the air inside the lungs. As a result the air comes out of the lungs to the atmosphere due to lack of space inside. Both the process of inhalation and exhalation is commonly known as breathing.
45. Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning. (3 marks)
Ans:
Alveoli
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Nephron
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Structure
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Structure
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(i) Alveoli are tiny balloon-like structures present inside the lungs.
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(i) Nephrons are tubular structures present inside the kidneys.
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(ii) The walls of the alveoli are one cell thick and it contains an extensive network of blood capillaries.
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(ii) Nephrons are made of glomerulus, bowman’scapsule, and a long renal tube. It also contains a cluster of thin-walled capillaries.
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Function
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Function
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(i) The exchange of O 2 and CO2 takes place between the blood of the capillaries that surround thealveoli and the gases present in the alveoli.
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(i) The blood enters the kidneys through the renal artery which branches into many capillaries in the glomerulus. The water and solute are transferred to the nephron at Bowman’s capsule. Then the filtrate moves through the proximal tubule and then down into the loop of henle. From henle’s loop, filtrate passes into the distal tubule and then to the collecting duct. The collecting duct collects the urine from many nephrons and passes it to the ureter. During the flow of filtrate, some substances such as glucose, amino acids, and water are selectively re-absorbed.
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(ii) Alveoli are the site of gaseous exchange.
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(ii) Nephrons are the basic filtration unit.
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46. Draw a diagram of human alimentary canal showing duodenum, small intestine, liver and pancreas. (3 marks)
47. State the two vital function of the human kidney.
48. Name the procedure used in the working of artificial kidney. (3marks)
Ans: (a) Function of Kidneys:
Absorption of water and salt
Removal of waste materials like urea, ammonia etc from blood
Blood pressure control
(b) Artificial kidney works on the principal of dialysis. It is also known as haemodialysis.
In hemodialysis, only a few drops of blood are allowed to flow, through a special filter that removes wastes and extra fluid. The detoxified blood is then returned to the body.
The special filter used in dialysis consists of a number of tubes with semi-permeable lining, suspended in a tank filled with the dialysis fluid.
49. What are the methods used by plants to get rid of excretory products? (5 marks)
Ans:
Plants get rid of carbon dioxide and oxygen through diffusion. Old branches and leaves are shed off when they become useless. Plants release some waste products through roots also. Some waste products are deposited near bark as raisins or gums.
50. . Give the energy transformation that takes place in the process of photosynthesis. (1 mark)
Ans: Light energy converted into chemical energy
51. Write any two functions of large intestine to man. (2 marks)
Ans(a) Inner lining of colon has numbers of villi that absorb water from undigested food and form solid waste
(b) Store solid secrete in rectum and spell out with anus
52. How are lungs designed in human beings to maximize the area for exchange of gases (2 marks)
Ans: The lungs get filled up with air during the process of inhalation as ribs are lifted up and diaphragm is flattened. The air that is rushed inside the lungs fills the numerous alveoli present in the lungs.
These numerous alveoli increase the surface area for gaseous exchange making the processof respiration more efficient.
53. Draw the human heart and label its parts. (2 marks)
Ans: See NCERT Figure 6.10 -Sectional view of the human heart
54. Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like human? (2 marks)
Ans: Diffusion is insufficient to meet the energy requirements of large multicellular organisms like humans because the volume of the human body is so big that oxygen the diffusion pressure alone cannot take care of oxygen delivery to all parts of the body. This is because oxygen has to travel large distances inside the body to reach each and every cell quickly but diffusion is a very slow process.
55. What is the role of the acid in our stomach? (2 marks)
Ans: The hydrochloric acid creates an acidic medium which facilitates the action of the enzyme pepsin and also kills bacteria present in food.
56. Draw a diagram & describe the process by which excretion occurs in amoeba. (3 marks)
Ans: Amoeba removes these wastes by simple diffusion from the body surface into the surrounding water.
[Amoeba is an ammonotelic organism since the principal excretory product is ammonia. Special excretory organelle in Amoeba is lacking. CO2 and ammonia are exerted by diffusing is solution through plasma membrane. The concentration of ammonia is always higher in Amoeba than in the surrounding water. The water enters through plasma membrane by “endosmosis”. Ammonia is formed in cytoplasm by metabolism. Surplus water enters contractile vacuole. This surplus water can rupture the animal’s body. Thus size of contractile vacuole increases, when the contractile vacuole is fully expanded with water, it moves towards the periphery. As it comes in close contact with the plasma membrane, the contractile vacuole bursts. Thus excess of water (surplus water) is discharged in the surrounding water, this phenomenon of controlling the amount of water in the body is called as “osmoregulation”. ]
57. How does blood circulate between lungs and heart in human beings? Give two functions of lymph in human body. (3 marks)
Ans: At first the impure blood from all the body parts reach the right auricle and then into right ventricle.From right ventricle it is carried to lungs through Pulmonary arteries .In lungs, it gets purified [alveoli do the purification] and then it is send to left auricle through Pulmonary Vein. From left auricle it flows into left ventricle and then to all the body parts through systemic aorta.
Lymph carries digested and absorbed fat from intestine and drains excess fluid from extra cellular space back into the blood.
58. 1 How do each of the following factors affect the productivity in the process of photosynthesis?
(i) Temperature (ii) Water (iii) Carbon dioxide. (3 marks)
(i) Temperature (ii) Water (iii) Carbon dioxide. (3 marks)
Ans: (i) Temperature : The higher the temperature then typically the greater the rate of photosynthesis, photosynthesis is a chemical reaction and the rate of most chemical reactions increases with temperature
(ii) Water : An increase in the amount of water leads to the increase in the amount of photosynthesis.
The amount of water available to the plant will affect the rate of photosynthesis. If the plant does not have enough water, the plant’s stomata will shut and the plant will be deprived of CO2, and thus lower photosynthesis rate .
(iii) Carbon dioxide. The concentration of carbon dioxide in the Earth’s atmosphere varies between 0.03% and 0.04%. An increase in the concentration of carbon dioxide gives an increase in the rate of photosynthesis.
59. Write necessary conditions for autotrophic nutrition and its by-products? (3 marks)
Ans: The necessary conditions for autotrophic nutrition are :
1. Sunlight 2.water 3.CO2 4.chlorophyll; It’s by-products are carbohydrates & oxygen
60. How are fats digested in our body? Where does this process take place? (3 marks)
Ans: Fats are present in the form of large globules in the small intestine. The small intestinegets the secretions in the form of bile juice and pancreatic juice respectively from the liver and the pancreas. The bile salts (from the liver) break down the large fat globules into smaller globules so that the pancreatic enzymes can easily act on them. This is referred to as emulsification of fats. It takes place in the small intestine.
61. (i) Draw a labeled diagram of the respiratory system of human beings with diaphragm at the end of expiration. (5 marks)
(ii) List four conditions required for efficient gas exchange in an organism
(ii) List four conditions required for efficient gas exchange in an organism
Ans:
(ii) (a)A large surface area over which exchange can take place.
(b) A concentration gradient without which nothing will diffuse.
(c) A thin surface across which gases diffuse.
(d) Warm conditions
62. What is source of O2 liberated during photosynthesis? (1 mark)
Ans: The main source of oxygen in the atmosphere during photosynthesis is photosynthetic [green] plants, cyanobacteria and algae which releases oxygen during photosynthesis. Other sources include the photolysis of atmospheric water and nitrous oxides by ultraviolet light and the free oxygen released from the silicates and mineral oxides present in the earth crust.
63. In which part of the digestive canal food is absorbed? (1 mark)
Ans: small intestine
64. Which organelle of the cell is known as ‘power house’? (1 mark)
Ans: Mitochondria
65. Why oxygenated and deoxygenated blood is separated in mammals and birds? (1 mark)
Ans: Oxygenated and deoxygenated blood is separated in mammals and birds as Such kind of separation allows a highly efficient supply of oxygen to the body . Birds and mammals constantly use energy to maintain their body temperature.
Ans: Oxygenated and deoxygenated blood is separated in mammals and birds as Such kind of separation allows a highly efficient supply of oxygen to the body . Birds and mammals constantly use energy to maintain their body temperature.
66. Name the functional unit of human kidney. (1 mark)
Ans: Nephron is the basic structural and functional unit of the kidney.
67. ‘Respiration is a vital function of the body’. Justify. (2 marks)
Ans: Respiration is the bodily process of inhalation and exhalation. Through this process, oxygen is inhaled. T his inhaled oxygen is used to burn/oxidize/break down the food (glucose). This reaction produces energy which is used to carry out various activities going on in our body. Our body need continuous supply of energy to carry out these activities. So, respiration is continuous processes which make us able to meet energy demand of our body. If respiration comes to halt the person will die
68. Differentiate between autotroph and heterotrophs. (2 marks)
Ans: Autotrophic nutrition means that the organism is preparing its own food and is not dependent on any other organism for food. Green plants are autographs.
Ans: Autotrophic nutrition means that the organism is preparing its own food and is not dependent on any other organism for food. Green plants are autographs.
Heterotrophic nutrition means that the organism does not prepare its own food and is dependent on other organisms for food. All organisms which are not among green plants are heterotrophic.
69. Mention the role of the valves in maintaining blood flow in the heart. (2 marks)
Ans: The valves present in the heart normally allow the blood to flow in only one direction. There are four valves in the heart – mitral valve, tricuspid valve, bicuspid valve and pulmonary valve. These valves control the flow of blood by opening and closing through the heart at the time of contraction.
Ans: The valves present in the heart normally allow the blood to flow in only one direction. There are four valves in the heart – mitral valve, tricuspid valve, bicuspid valve and pulmonary valve. These valves control the flow of blood by opening and closing through the heart at the time of contraction.
70. What is the structural difference between the auricles and ventricles? (2 marks)
Ans: The arteries have thick, elastic walls. They do not have valves
Ans: The arteries have thick, elastic walls. They do not have valves
The Veins do not have thick, elastic walls. They have valves.
71. How are lungs designed in human beings to maximize the area for exchange of gases(3marks)
Ans: Within the lungs, the bronchi divides into smaller and smaller tubes called bronchus which finally terminate in balloon-like structures which are called alveoli. The alveoli provide a surface where the exchange of gases can take place. The walls of the alveoli contain an extensive network of blood-vessels.
Ans: Within the lungs, the bronchi divides into smaller and smaller tubes called bronchus which finally terminate in balloon-like structures which are called alveoli. The alveoli provide a surface where the exchange of gases can take place. The walls of the alveoli contain an extensive network of blood-vessels.
72. How are water and minerals transport in plants? (3 marks)
Ans: The components of xylem tissue (tracheids and vessels) of roots, stems, and leaves are interconnected to form a continuous system of water-conducting channels that reaches all parts of the plant. Transpiration creates a suction pressure, as a result of which water is forced into the xylem cells of the roots. Then there is a steady movement of water from the root xylem to all the plant parts through the interconnected water-conducting channels.
73. How is food transported in plants? (3 marks)
Ans: Food is transported in plants through phloem. The transport in phloem is an active process and involves use of energy. The energy in the form of ATP created osmotic gradient which results in transportation of food through phloem.
Ans: Food is transported in plants through phloem. The transport in phloem is an active process and involves use of energy. The energy in the form of ATP created osmotic gradient which results in transportation of food through phloem.
74. (i) What are the functions of liver and pancreas in the digestive system? (5 marks)
(ii) Which part of the body secretes bile? Where is bile stored? (iii) What is trypsin? What is its function?
(ii) Which part of the body secretes bile? Where is bile stored? (iii) What is trypsin? What is its function?
Ans:(i) Liver and pancreas play key roles in the digestive system. Liver secretes bile juice which helps in emulsification and digestion of fat molecules. It also aids in absorption of fat soluble vitamins like A, D E, K. While pancreas secrete pancreatic juice containing several enzymes that help in carbohydrate metabolism.
(ii) Bile is secreted by liver. It is stored in the gall bladder till required.
(iii) Trypsin is secreted by the duodenum of small intestine. When proteins are digested in the stomach the acidic medium is passed as such into the small intestine. The small intestineis incapable of handling such low pH and neither can its enzymes function. Hence Trypsin is released to neutralize the acidity
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