Multiple Choice QuestionsWhat is common between chloroplasts, chromoplasts and leucoplasts
Presence of pigments
Possession of thylakoids and grana
Storage of starch, proteins and lipids
Ability to multiply by a fission-like process
Assertion: Our body secretes adrenaline in intense cold.
Reason: Adrenaline raises metabolic rate.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Assertion: When the ambient temperature is high and soil contains excess of water, the plants tend to lose water in the form of droplets from lenticels.
Reason: Root pressure regulates the rate of loss of water form lenticels
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Assertion: In angiosperms the conduction of water is more efficient because their xylem has vessels.
Reason: Conduction of water by vessel elements is an active process with energy supplied by xylem parenchyma rich in mitochondria
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
C.
If assertion is true but reason is false
Xylem is the main conducting tissue in plants. It consists of 4 different components-tracheids, trachea or vessels, xylem fibre and xylem parenchyma.
Tracheids are elongated cells with tapering end. They arc generally present in ferns and gymnosperms for conduction of water. In angiosperms, vessels are composite structure as these are formed by dissolution of end walls of row of cells i.e., vessels elements. So angiosperms, have more efficient system of conduction due to presence of vessels. Conduction of water by vessel elements is also known as ascent of sap. Water absorbed by roots, goes upward to replace the water loss by transpiration. The most accepted theory for ascent of sap is transpiration pull theory i.e., when water is lost by transpiration from the leaves, a tension is created in the xylem and due to this water absorbed by roots hair is passed through vessels to the leaves. The xylem parenchyma are mainly for storage function but sometimes help in conduction.
Assertion: Gram-negative bacteria do not retain the stain when washed with alcohol.
Reason: The outer face of the outer membrane of Gram-negative bacteria contains lipopolysaccharides, a part of which is integrated into the membrane lipids
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Assertion: Under conditions of high light intensity and limited CO2 supply,
photorespiration has a useful role in protecting the plants from photo-oxidative damage.
Reason: If enough CO2 is not available to utilize light energy for carboxylation to proceed, the excess energy may not cause damage to plants.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Assertion: Photosynthetically C4 plants are less efficient than C3 plants.
Reason: The operation of C4 pathway requires the involvement of only bundle-sheath cells.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is falsen
If both assertion and reason are false.
Assertion: Eukaryotic cells have the ability to adopt a variety of shapes and carry out directed movements.
Reason: There are three principal types of protein filaments - microfilaments, microtubules and intermediate filaments, which constitute the cytoskeleton.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Which one of the following pairs of features is a good example of polygenic inheritance
Human height and skin colour
ABO blood group in humans and flower colour of Mirabilis jalapa
Hair pigment of mouse and tongue rolling in humans
Human eye colour and sickle cell anaemia
Mating of an organism to a double recessive in order to determine whether it is homozygous or heterozygous for a character under consideration is called
reciprocal cross
dihybrid crossn
test cross
back cross
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