CBSE Test Paper-03
Chapter 06 Life Processes
1. Raisins swell up after being placed them in a beaker containing water for sometime
because: (1)
a. the concentration of water in the cell sap is the same as that of water in the beaker
b. water inside the raisins passes out of them when placed in a beaker of water
c. the concentration of water in the cell sap is higher than the water in the beaker.
d. the concentration of water in the cell sap is lower than the water in the beaker
2. Match the following with correct response. (1)
(1) Saliva (A) sucrose
(2) Gastric juice (B) Pepsin
(3) Pancreatic juice (C) Amylase
(4) Succuss entricus (D) Trypsin
a. 1-A, 2-C, 3-B, 4-D
b. 1-C, 2-B, 3-D, 4-A
c. 1-B, 2-D, 3-A, 4-C
d. 1-D, 2-A, 3-C, 4-B
3. Three students Jagdeep, Gautam and Gurdev get 10 gm raisins equally. They soaked
the raisins in distilled water at room temperature. They removed the raisins after 35
minutes. 1 hour 15 minutes and 2 hours respectively. Who got more percentage
absorption of water? (1)
a. Gurdev
b. Gautam
c. Jagdeep, Gautam and Gurdev
d. Jagdeep
4. Which is the vestigial part of human alimentary canal? (1)
a. epiglottis
b. pineal gland
c. thymus gland
d. Vermiform appendix
5. If the water absorbed by soaked raisins is 50% then the weight of raisins before
soaking in water W1 and the weight of raisins after soaking in water W2 might have
been (1)
a. W1 = 30g and W2 = 50 g
b. W1 = 50g and W2 = 100 g
c. W1 = 5 g and W2 = 25 g
d. W1 = 20g and W2 = 30 g
6. Name the exchange of gases between the blood and the air at the respiratory surface.
(1)
7. When do viruses show movements? (1)
8. Which of these blood vessel carry less nitrogenous waste - renal vein or the renal
artery? (1)
9. After drinking access of cold drink, a person suffered from acidity. Explain? (1)
10. What is the advantage of four chambered of heart? (3)
11. The pulse rate increases due to physical exercise. Why? (3)
12. A girdled tree dies if the girdle is wide and is not filled up. comment. (3)
13. State the function of Bowman's capsule and glomerulus. (3)
14. Describe the structure and functioning of nephrons. (5)
15. Draw the diagram of part of leaf from which transpiration takes place. Explain
stomatal or foliar transpiration. (5)
Answers
1. c. the concentration of water in the cell sap is higher than the water in the beaker.
Explanation: Due to osmosis, water moves from lower concentrated solution
to higher concentrated solution.
2. b. 1-C, 2-B, 3-D, 4-A
Explanation:
An amylase is an enzyme that catalyses the hydrolysis of starch into
sugars. Amylase is present in the saliva of humans and some other
mammals.
Pepsin is the powerful enzyme in gastric juice that digests proteins such
as those in meat, eggs, seeds, or dairy products.
Three enzymes found in pancreatic juice, called trypsin, chymotrypsin
and carboxypeptidase, are the pancreatic enzymes that complete the
digestion of proteins. Because proteins are held together by peptide
bonds, these enzymes work by breaking peptide bonds.
The ileum and the jejunum parts of the small intestines secrete a
combination of several enzymes called succus entericus. Succus
entericus contains sucrose which is used in the breakdown of sucrose
into fructose and glucose.
3. a. Gurdev
Explanation: Absorption of water increases with time upto its maximum
limit.
4. d. Vermiform appendix
Explanation: Vestigial organs can be defined as an organ that once was useful
in an animal's evolutionary past, but that now is useless or very close to useless.
As vermiform appendix plays no significant function in humans, so it is
considered as a vestigial organ.
5. d. W1 = 20g and W2 = 30 g
Explanation:
6. External respiration
7. When the virus is outside the living body they as they are dead but by entering the
living body they start showing molecular movement.
8. Renal vein carries deoxygenated but purified blood (has less nitrogenous waste) away
from the kidney.
9. Cold drinks contain carbon dioxide dissolved in them under pressure. some amount
of the gases escape when a bottle of cold drink is opened while a portion of it remain
dissolved. Carbon dioxide dissolved in water from a weak acid, carbonic acid.
consumption of excess of cold drink accumulation of carbonic acid in the stomach
which is responsible for the development of acidity.
10. The right and left parts are separated by a septum to prevent oxygenated and
deoxygenated blood from mixing. This is particularly advantageous in warm-blooded
animals such as birds and mammals who constantly use energy to maintain their
body temperature.
11. The arteries expand as the ventricles pump this blood out of the heart, and this is
known as a pulse. Fundamentally, exercise will increase the need for additional food,
known as energy, and oxygen in the body. The breathing will increase to rid the body
of carbon dioxide and to provide more oxygen, and the pulse will increase to provide
the extra food and oxygen needed.
12. Girdling removes bark containing phloem from the trunk region. Food manufactured
foliage does not reach the roots which requires the same as they are always growing.
In the absence of food supply, roots starve and stop absorbing water. The foliage wilts
and the plants dies.
13. Bowman’s capsule and glomerulus have semipermeable walls. The glomerulus, is a
tuft of capillaries contained in Bowman’s capsule. The water and dissolved substances
(wastes and useful) are filtered into the Bowman’s capsule and from here they are
sent into the tubule. Thus, both the structures act as filtering apparatus.
14. Structure of Nephron: Nephron is the structural and functional unit of kidney.
i. It consists of a long coiled tubule differentiated into proximal tubule, loop of Henle
and distal tubule. The latter opens into the collecting tubule.
ii. At the proximal end of the nephron lies a double-walled cup-shaped structure
called Bowman’s capsule.
iii. The Bowman’s capsule contains a bundle of blood capillaries which is called
glomerulus.
iv. In the glomerulus, the blood that comes in through afferent arteriole is drained
out through efferent arteriole.
Functions of Nephron:
i. Filtration: Filtration of blood takes place in Bowman’s capsule from the capillaries
of glomerulus. This takes place under high pressure. The filtrate passes into the
tubular part of the nephron. This filtrate contains glucose, amino acids, urea, uric
acid, salts and major amount of water.
ii. Selective Reabsorption: As the filtrate flows along the tubule, useful substances
such as glucose, amino acids, salts and water are selectively reabsorbed into the
blood by capillaries surrounding the nephron tubule. The amount of water
reabsorbed depends on the need of the body and also on the amount of wastes to
be excreted.
iii. Tubular secretion: Certain substances which are harmful and not needed by the
body like ammonia, potassium, creatinine and hydrogen ions are secreted from
the capillary blood into the lumen of distal tubule. This is called tubular secretion.
15. Stomatal transpiration: The epidermis has minute pores called stomata. Each
stoma is surrounded by two specialised epidermal cells called guard cells. The guard
cells are kidney-shaped, process chloroplasts and less elasticity. Adjacent to the
epidermal cells, their walls are thin and elastic. They are thickened near the openings.
The stomata remain open in light and close in darkness. Guard cells control the
opening or closing of stomata.
The stomata form the chief pathway of transpiration. Though the relative total area of
the stomatal pore is 1-2% of the total area of the leaf, more transpiration takes place
through these stomata only.
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