The autotrophic mode of nutrition requires :
carbon dioxide and water
chlorophyll
sunlight
all of the above
(4)
In the autotropic mode of nutrition, the plants can prepare their own food in the presence of sunlight, carbon dioxide, water and chlorophyll present in the leaves of the plants.
A student covered a leaf from a destarched plant with a black paper strip and kept it in the garden outside his house in fresh air. In the evening he tested the covered portion of the leaf for the presence of starch. By doing so the student was trying to show that:
is given out during respiration.
is necessary for photosynthesis.
Chlorophyll is necessary for photosynthesis.
Light is necessary for photosynthesis.
(4)
Only in the presence of sunlight autotrophs can convert carbon dioxide and water into carbohydrates. By covering the leaf by black paper strip the leaf does not get sunlight in the covered part and no photosynthesis takes place and no starch will be present in the leaf thus light is necessary for photosynthesis.
A few drops of iodine solution were added to rice water. The solution turned blue-black in colour. This indicates that rice water contains :
Complex proteins
Simple proteins
Starch
Fats
(3)
Due to the presence of starch, when iodine solution was added to rice water, the solution becomes blue-black. Iodine forms starch iodide complex when it comes in contact with the amylose structure of starch. The blue-black colour comes from the starch iodide complex.
The opening and closing of stomatal pores depends upon
Oxygen
Water in guard cells
Concentration of carbon dioxide in stomata
Temperature
(2)
The entry of water into guard cells aids in the opening of guard cells, the guard cell becomes turgid as a result of this. Water going out from guard cells aids in the closing of guard cells, as a result of this the guard cells become flaccid.
In which of the following groups of organisms, food material is broken down outside the body and absorbed ?
Mushroom, green plants, amoeba
Yeast, mushroom, bread mould
Paramecium, amoeba, cuscuta
Cuscuta, lice, tapeworm
(2)
Yeast, mushrooms, and bread mould all exhibit a saprophytic mode of nutrition. They use digestive enzymes secreted outside their body to break down complex organic substances and absorb basic molecules as nutrition.
If salivary amylase is lacking in the saliva, which of the following events in the mouth cavity will not take place properly?
Proteins breaking down into amino acids
Starch breaking down into sugars
Fats breaking down into fatty acids and glycerol
Absorption of vitamins
(2)
Amylase is a starch hydrolase enzyme that catalyses the conversion of starch to simple sugars. As a result, if salivary amylase is lacking in saliva, starch digestion is hampered.
Bile from the liver is received in which part of the alimentary canal?
Stomach
Small intestine
Large intestine
Oesophagus
(2)
Bile is a dark green to yellowish brown fluid produced by the liver. It is stored in the gall bladder and it helps in the digestion of fats in the small intestine.
In which part of alimentary canal food is finally digested ?
Stomach
Mouth cavity
Large intestine
Small intestine
(4)
Food is broken down in the small intestine by enzymes secreted by the pancreas and bile from the liver. Because it contains all of the enzymes required for the digestion of every type of food, the food is finally digested in the small intestine of the alimentary canal.
Choose the function of pancreatic juice from the following.
Trypsin digests proteins and lipase digests carbohydrates.
Trypsin digests emulsified fats and lipase digests proteins.
Trypsin and lipase digest fats.
Trypsin digests proteins and lipase digests emulsified fats.
(4)
Pancreatic juice contains the digestive enzymes amylases, lipases, and trypsin, which are secreted by the pancreas. Amylase degrades starch, trypsin degrades proteins, and lipase degrades emulsified lipids.
The pancreatic juice does not contain one of the following enzymes.
Trypsin
Amylase
Lipase
Ptyalin
(4)
Ptyalin, also known as salivary amylase, is an enzyme that is found in the saliva of humans and some other animals. It begins the process of starch digestion in the mouth. While the pancreas does produce digestive enzymes like trypsin, amylase, and lipase, which are crucial for breaking down proteins, carbohydrates, and fats respectively, it does not produce ptyalin.
