Assertion (A): Amount of secondary xylem produced is more than the secondary phloem in the dicot stem.
Reason (R): Cambium is generally more active on the inner side than on the outer.
1. If both Assertion & Reason are true and the reason is the correct explanation of the assertion.
2. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion.
3. If Assertion is a true statement but the reason is false.
4. If both Assertion and Reason are false statements.
A: The secondary xylem is derived from procambium during secondary growth.
R: The amount of secondary xylem is almost equal to the amount of secondary phloem.
1. If both Assertion & Reason are true and the reason is the correct explanation of the assertion.
2. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion.
3. If the Assertion is a true statement but the reason is false.
4. If both Assertion and Reason are false statements.
Mark the correct statements with respect to meristematic tissues
A. | The meristem that occurs at the tip of roots and shoots contributes to the formation of the primary plant body. |
B. | The lateral meristems are responsible for producing the secondary tissues. |
C. | Some cells 'left behind' from the lateral meristem, constitute the axillary bud. |
D. | The cells which are structurally and functionally specialised and lose the ability to divide are called meristems. |
1. | A & C | 2. | A & B |
3. | B & C | 4. | C & D |
Identify the incorrect statement.
1. | Sapwood is involved in conduction of water and minerals from roots to leaves. |
2. | Sapwood is the innermost secondary xylem and is lighter in colour |
3. | Due to deposition of tannins, resins, oils etc., heartwood is dark in colour. |
4. | Heart wood does not conduct water but gives mechanical support. |
Secondary medullary rays are
1. Narrow band of parenchyma
2. Arranged transversely
3. Dead and dignified
4. Formed by primary cambium
Which of the following structures labelled as A, B, C and D represents complete and continuous wavy ring of vascular cambium?
1. A
2. B
3. C
4. D
Heart wood is differentiated from sap wood in being
1. Peripheral in position
2. Resistant to the attack of microorganisms and insects
3. Lighter in colour and dignified
4. hard, durable and help in conduction of water
All are the features of heart wood, except
A. Forms greater part of secondary xylem in old trees.
B. Light in colour.
C. Constitutes peripheral region of secondary xylem.
D. It is hard and durable due to deposition of organic compounds, essential oils etc.
E. It is physiologically active and is comprised of living elements.
F. Involved in the conduction of water and minerals from root to leaf
1. A, D & F
2. B, C, E & F
3. D, E & F
4. B, D & E
Arrange the following diagrams in correct order according to the events occurring during secondary growth in dicot stem.
1. b, d, c, a
2. b, a, d, c
3. d, a, b, c
4. d, b, a, c
During secondary growth in dicot root
1. Vascular cambium arises completely from conjunctive parenchyma
2. Growth rings are distinct with spring wood alternating with autumn wood
3. Phellogen arises from the epidermis
4. Vascular cambium is complete and continuous wavy ring