Biology
Assertion (A): A plant should be placed in dark for 24 to 48 hours before using it for experiments on photosynthesis.
Reason (R): During this period, all the starch from the leaves, is either utilized in the process of respiration or stored in the storage organs.
- A is True and R is False.
- A is False and R is True.
- Both A and R are True.
- Both A and R are False.
Answer
Both A and R are True.
Explanation
The plant is kept in the dark for 24 to 48 hours to destarch it. In the absence of light, photosynthesis does not occur, so no new starch is formed. During this time, the starch already present in the leaves is used in respiration or transported to the storage organs.
Related Questions
Assertion (A): Palisade cells of mesophyll are loosely arranged towards the lower epidermis of a dorsiventral leaf.
Reason (R): Palisade cells contain the maximum amount of chlorophyll, trap solar energy and help in the process of photosynthesis.
- Both A and R are True
- Both A and R are False
- A is True and R is False.
- A is False and R is True.
Assertion (A): Phosphorylation occurs in all organisms only during the process of respiration.
Reason (R): Photophosphorylation is the process during which ADP combines with inorganic phosphate (iP) and produces ATP.
- Both A and R are True
- Both A and R are False
- A is True and R is False.
- A is False and R is True.
Name the following:
(a) The category of organisms that prepare their own food from basic raw materials.
(b) The kind of plastids found in the mesophyll cells of the leaf.
(c) The compound which stores energy in the cells.
(d) The first form of food substance produced during photosynthesis.
(e) The source of CO2 for aquatic plants.
(f) The part of chloroplast where the dark reaction of photosynthesis takes place.
Given below are groups of terms. In each group, the first pair indicates the relationship between the two terms. Complete the second pair accordingly.
(a) Chlorophyll : Magnesium :: Haemoglobin : …………… .
(b) Light reaction : Granum :: Dark reaction : …………… .
(c) Producers : Autotrophs :: Consumers : …………… .
(d) Respiration : Carbon dioxide :: Photosynthesis : …………… .
(e) Water and minerals : Xylem :: Prepared food : …………… .