Heartwood and Sapwood

Q.

What are the uses of wood?

Q. List some of the tissues in a woody dicotyledonous plant that are the products of redifferentiation. How would you describe a tumour?

Q.

Identify the wrong statement in the context of heartwood:

1. It conducts water and minerals efficiently
2. It comprises dead elements with highly lignified walls
3. Organic compounds are deposited in it
4. It is highly durable

Q. Read the assertion and reason carefully to mark the correct option in question.

Assertion: In plants differentiation is open.
Reason: Cells or tissues arising out of the same meristem have different structures at maturity.

1. If assertion is true but reason is false.
2. If both assertion and reason are true and the reason is the correct explanation of the assertion.
3. If both assertion and reason are true but reason is not the correct explanation of the assertion.
4. If both assertion and reason are false.

Q. The feature which is common to both heartwood and sapwood is

1. both comprise dead elements with accumulation of aromatic compounds
2. both are the regions of secondary xylem
3. both are involved in the conduction of water
4. both are located in the central layers of the stem

Q.

Why are a greater part of older trees dark brown?

Q. As secondary growth proceeds, in a dicot stem, the thickness of

1. Both sapwood and heartwood increases
2. Both sapwood and heartwood remains the same.
3. Sapwood increases
4. Heartwood increases

Q. The wood that comprises dead elements with highly lignified walls is called .

1. sapwood
2. early wood
3. late wood
4. heartwood

Q.

The outer wall of epidermis in stems and leaves has a waxy covering made up of ------------------------

1. Lignin

2. Suberin

3. Pectin

4. Cutin

Q.

What is Duramen or heartwood?

Q.

What do hardwood and softwood stand for?

Q.

Vertical growth in plants takes place by?

Q. In a plant organ, which is covered by periderm and in which the stomata are absent, some gaseous exchange still takes place through

1. pneumatophores
2. trichomes
3. lenticels
4. aerenchyma

Q. Secondary wall grows in thickness by

1. Introgression
2. Accretion
3. Epiboly
4. Intercalation

Q. Study carefully the following statements and select the incorrect one(s).
(i) Lateral roots develops from pericycle.
(ii) Endodermis is the innermost layer of cortex.
(iii) Sapwood is the central, dark coloured, non-conducting part of secondary xylem.

1. (i) and (ii)
2. (ii) and (iii)
3. (i) only
4. (iii) only

Q.

What Is Duramen Or Heartwood?

Q. The balloon shaped structures called tyloses

1. Characterize the sapwood
2. Are linked to the ascent of sap through xylem vessels
3. Originate in the lumen of vessels
4. Are extensions of xylem parenchyma cells

Q.

Why is differentiation in plants said to be open?

Q. Identify the correct statement in context of sapwood:

1. Durable in damp locations.
2. Comprises dead elements with highly lignified walls.
3. It contains valuable extractable materials like tannin and dyes.
4. It is highly efficient in conducting water and minerals.

Q. Match the different type of wood to the correct option.

1. Early wood
2. Late wood
3. Only angiosperms
4. Only gymnosperms

Q. Read the following statements.
A. Heartwood is durable, dark and central in position.
B. Tyloses are balloon like outgrowths of xylem parenchyma into the lumen of vessels.
C. Late wood is formed during spring season.

1. All are correct
2. Only A is correct
3. Only B is incorrect
4. Only C is incorrect

Q. Which of the following are involved in the conversion of sapwood into heartwood?

1. By deposition of resins, oils, gums, etc
2. By degeneration of protoplast of living cells
3. Tyloses formation
4. All of the above

Q.

Timber producing tree is __________.

1. teak

2. banana

3. peepal

4. none of these

Q. The wood that comprises dead elements with highly lignified walls is called .

1. sapwood
2. early wood
3. late wood
4. heartwood

Q. How many of the following statement(s) is/are correct regarding secondary growth?

A. Secondary tissues are formed from lateral meristems.
B. Gymnosperms show secondary growth.
C. Periderm is a secondary tissue that helps in secondary growth.
D. Because of the presence of vascular cambium, secondary growth does not occur in monocots.

1. One
2. Two
3. Three
4. Four

Q.

Name any two regions where sclereids can be seen.

Q. Out of diffuse porous and ring porous woods, which is correct?

1. Ring porous wood carries more water for short period.
2. Diffuse porous wood carries more water.
3. Ring porous wood carries more water when need is higher.
4. Diffuse porous wood is less specialised but conducts water rapidly throughout.

Q. Heartwood differs from sapwood in

1. being susceptible to pests and pathogens
2. presence of rays and fibres
3. absence of vessels and parenchyma
4. having dead and non-conducting elements

Q. Maam what is the difference between ring porous and diffused porous wood ?

Q.

1. (ii), (iii) and (iv)
2. (ii) and (iv)
3. (i), (ii) and (iii)
4. (i) and (iv)