- Fascicular cambium separates the xylem and phloem in
(a) dicots only
(b) monocots only
(c) both dicots and monocots
(d) none of the above. (UP CPMT 2015)- When one wood is lighter in colour with a lower density, the
other wood is darker with a higher density. They are
(a) spring wood and autumn wood
(b) heart wood and late wood
(c) spring wood and early wood
(d) sapwood and spring wood
(e) autumn wood and spring wood. (Kerala PMT 2014)- During secondary growth the amount of secondary xylem
produced is more than the secondary phloem because
(a) the cambium is more active on the inner side
(b) the cambium is more active on the outer side
(c) the cambium is equally active on both sides but the
xylem is needed more
(d) the cambium has no role to play in this difference.
(AMU 2013)- Cork cambium of dicot stem originates from
(a) dedifferentiated parenchyma cells of cortex
(b) dedifferentiated collenchyma cells of cortex
(c) parenchyma cells of medullary ray
(d) parenchyma cells of pericycle. (Karnataka CET 2013) - The common bottle cork is a product of
(a) dermatogen (b) phellogen
(c) xylem (d) vascular cambium.
(AIPMT Prelims 2012)- Which one of the following is not correct?
(a) Early wood is characterised by large number of xylary
elements.
(b) Early wood is characterised by vessels with wider
cavities.
(c) Late wood is characterised by large number of xylary
elements.
(d) Late wood is characterised by vessels with narrower
cavities. (AMU 2010) - Medullary rays are made up of
(a) parenchymatous cells (b) sclerenchymatous cells
(c) tracheids (d) fibres. (AMU 2010) - What is/are true about heartwood?
A. It does not help in water conduction.
B. It is also called alburnum.
C. It is dark in colour but very soft.D. It has tracheary elements which are filled with tannin,
resin, etc.
(a) B and D (b) A, B and C
(c) B, C and D (d) A and D
(Karnataka CET 2009)Assertion & Reason
The following questions consist of two statements each : assertion
(A) and reason (R). To answer these questions, mark the correct
alternative as directed below :
(a) If both A and R are true and R is the correct explanation of A.
(b) If both A and R are true but R is not the correct explanation of A.
(c) If A is true but R is false.
(d) If both A and R are false.- Assertion : Sapwood is less durable.
Reason : Sapwood is resistant to microbial attack. - Assertion : Softwood is also known as nonporous wood.
Reason : Softwood is devoid of vessels. - Assertion : In dicot root vascular cambium is a wavy band
in the early stage of its activity.
Reason : In dicot root vascular cambium is secondary in
origin. - Assertion : The age of a plant can be determined by
counting the number of annual rings.
Reason : Annual ring formed in single year consists of
softwood and hardwood. - Assertion : Periderm is the secondary meristem giving rise
to cells on both the sides.
Reason : Phellogen, phellem and periderm together
constitute the phelloderm.
Short Answer Type Questions
- Fill in the blanks.
(i) As the secondary xylem is formed on the inner side,
the vascular cambium slowly moves to outside with
the formation of new cells. This process is known as
.
(ii) is the science of counting and analysing
annual growth rings of trees.
(iii) The ingrowth of adjacent parenchyma cells into
the tracheids and vessels of heartwood are called
___. - Write a short note on cork with its economic importance.
- Differentiate between phellem and phelloderm.
- Illustrate the secondary growth in a typical dicot stem with
the help of a labelled diagram.