1. In dicot roots cork cambium originates in
(a) pith (b) hypodermis
(c) pericycle (d) endodermis.
2. Differential division of RAM gives rise to
(a) protoderm (b) procambium
(c) calyptrogen (d) all of these.
3. Which of the following is a primary lateral meristem?
(a) Interfascicular cambium
(b) Intrafascicular cambium
(c) Cork cambium
4. During secondary growth in dicot root phellogen form_____ towards outerside.
(a) periderm (b) secondary vascular tissue
(c) cork cambium (d) phellem.
5. Spring wood is _____ than autum wood, ____ in colour and _____ in density.
(a) wider, lighter, lower (b) narrower, lighter, lower
(c) wider, dark, higher (d) narrower, dark, higher.
6. Growth is a
(a) reversible increase in size
(b) reversible increase in shape
(c) irreversible increase in size
(d) none of the above
7. Meristem which is consumed in the formation of organ is
(a) determinate meristem
(b) indeterminate meristem
(c) secondary meristem
(d) lateral meristem.
8. Cells enter _______ phase for undergoing differentiation.
(a) G1 (b) S
(c) G0 (d) G2.
9. Cell enlargement may occur in
(a) all directions (b) linear direction
(c) both (a) and (b) (d) none of these.
10. Sap wood is
(a) outer wood of an old stem
(b) central wood of an old stem
(c) non functional part of secondary stem
1. As a tree grows older, which of the following increases more rapidly in thickness?
(a) Heart wood (b) Sap wood
(c) Phloem (d) Cortex. (CBSE-PMT 1994)
2. Cork cambium and vascular cambium are the examples of
(a) apical meristem (b) lateral meristem
(c) wound tissue (d) intercalary meristem. (DPMT 1991, 1995; CMC Vellore 2013 )
3. Procambium is situated just behind apical meristem. Procambium gives rise to
(a) vascular cambium (b) primary vascular bundle
(c) cork cambium (d) both (a) and (c). (DPMT 1993, 2001)
4. Vascular cambium in roots takes its origin from
(a) pericycle (b) conjunctive parenchyma
(c) both (a) and (b) (d) none of these
(DPMT 2004, 2006)
5. Secondary growth in dicot stem is the activity of
(a) xylem (b) cork cambium
(c) vascular cambium (d) both (b) and (c). (Manipal 1995)
6. Annual rings are distinct in plants, which grow in
(a) tropical regions (b) grass land
(c) temperate region (d) arctic regions. (Manipal 1999)
7. Which of the following is not a character of meristematic tissue?
(a) Presence of prominent nucleus
(b) Intercellular space present
(c) Absence of vacuole
(d) Proplastid present. (Manipal 2004)
8. Growth in numbers is maximum in the zone of
(a) cell maturation (b) cell division
(c) cell elongation (d) all of these. (AFMC 1994)
9. When seed germinates, while the fruit is attached to
the parent plant, it is called
(a) parthenocarpy (b) vivipary
(c) apomixis (d) parthenogenesis (BHU 1996)
10. Which of the following four phases, in the post emergence life of an angiospermic plant, begins just after germination of seed and ends when the plant develops the capacity to reproduce?
(a) Death (b) Maturity
(c) Ageing (d) Juvenility (DPMT 1998)
11. Vascular tissues in flowering plants develop from
(a) periblem (b) dermatogen
(c) phellogen (d) plerome.
(CBSE– PMT 2008)
12. Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by
(a) absence of secondary phloem
(b) presence of cortex
(c) position of protoxylem
(d) absence of secondary xylem (CBSE– PMT 2009)
13. Heartwood differs from sapwood in
(a) presence of rays and fibres
(b) absence of vessels and parenchyma
(c) having dead and non-conducting elements
(d) being susceptible to pests and pathogens. (AIPMT Prelims 2010)
14. Which one of the following pairs is an example for lateral meristem?
(a) Procambium and phelloderm
(b) Interfascicular cambium and phellem
(c) Phellogen and phelloderm
(d) Phellogen and fascicular cambium. (Karnataka 2010)
15. Youngest layer of secondary xylem in wood of dicot plants is located between
(a) pith and primary xylem
(b) just outside vascular cambium
(c) just inside vascular cambium
(d) just inside cork cambium. (Kerala 2000)
16. Secondary growth of dicot stem is due to
(a) phelloderm (b) bark
(c) lateral meristem (d) wood cork. (Manipal 2000)
17. Root cap is formed by
(a) dermatogen (b) calyptrogen
(c) vascular cambium (d) wound cambium. (AIIMS 2000)
18. The apical meristem of the root is present
(a) only in radicals (b) only in tap roots
(c) only in adventitious roots
(d) in all the roots (CBSE– PMT 2003)
19. Between the bark and the wood in a woody stem, there is a layer of meristem called
(a) cork cambium (b) apical meristem
(c) vascular cambium (d) the zone of cell division (Manipal 2006)
20. The secondary meristem initiates
(a) basal growth (b) transverse growth
(c) radial growth (d) vertical growth (J & K 2007)
21. Intercalary meristem occurs at the
(a) bases of internodes of monocot plants
(b) buds of the axillary leaves
(c) apex of dicot stem
(d) between the phloem and xylem (J & K 1998)
22. Secondary cortex is also known as
(a) phellem (b) phelloderm
(c) phellogen (d) bark. (Karnataka 2012)
23. The cork cambium, cork and secondary cortex are collectively called
(a) phelloderm (b) phellogen
(c) periderm (d) phellem
(AIPMT Prelims 2011)
24. Which one of the following is not a lateral meristem?
(a) Intrafascicular cambium
(b) Interfascicular cambium
(d) Intercalary meristem. (AIPMT Prelims 2010)
25. Which one of the following is not correct?
(a) Early wood is characterized by large number of xylary elements
(b) Early wood is characterized by vessels with wider cavities
(c) Late wood is characterized by large number of xylary elements
(d) Late wood is characterized by vessels with narrower cavities. (AMU 2010)
ASSERTION AND 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.
1. Assertion (A) : Vascular cambium is single layered but
appears to be 2-3 layer in thickness due to presence of immediate derivatives.
Reason (R) : Cells of vascular cambium divide by unipolar division to form secondary permanent tissue.
2. Assertion (A) : Cells of the meristematic region enter G0 phase.
Reason (R) : Cells of meristem undergo differentiation to form a particular tissue or organ.
3. Assertion (A) : Germinating seeds respire slowly.
Reason (R) : Germinating seeds require only anaerobic environment for initiations of germination.
4. Assertion (A) : Intercalary meristem helps in elongation of the organs.
Reason (R) : Intercalary meristematic regions are derived from the apical meristem.
5. Assertion (A) : Abnormal type of secondary growth occur in some arborescent monocots.
Reason (R) : In arborescent monocot stem stems, secondary cambium grows in hypodermal region.
SHORT ANSWER TYPE QUESTIONS
1. Fill in the blanks.
(a) Water is essential for _______ of the growing cells.
(b) Pith cells are living cells, with little _______ and _______ in their walls.
(c) Lateral meristems involved in secondary growth of a plant are _______ and _______.
(d) Strain at the circumference of the stem resulting
from secondary thickening causes epidermis to _______.
2. Summarise the effect of abiotic factors on germination.
3. Differentiate between heart and sap wood.
4. Describe the role of two meristems involved in secondary growth of dicot root.
Part – I
1. (c) 2. (d) 3. (b) 4. (d) 5. (a)
6. (c) 7. (a) 8. (c) 9. (a) 10. (a)
Part – II
1. (a) 2. (b) 3. (b) 4. (c) 5. (d)
6. (c) 7. (b) 8. (b) 9. (b) 10. (d)
11. (d) 12. (c) 13. (c) 14. (d) 15. (c)
16. (c) 17. (a) 18. (d) 19. (c) 20. (c)
21. (a) 22. (b) 23. (c) 24. (d) 25. (c)
Part – III
1. (c) 2. (d) 3. (d) 4. (b) 5. (a)
Part – IV
1. (a) vacuolation
(b) thickening, no lignification
(c) vascular cambium, cork cambium
2. Necessary abiotic factors for germination are water, temperature and oxygen. Seed imbibes water and the resultant swelling may rupture the seed coat. Water is also essential for vacuolation of the growing cells for activation of enzymes, hydrolysis of stored substances and translocation of hydrolysis of food reserve to the site of growth of embryo. Optium temperature is necessary to enzymatic activity and energy for metabolism and growth comes through respiration.
3. Differences between sapwood or alburnum and heartwood or duramen are summarised in the given table.
|1||It is outer wood of an old
|It is the central wood of
an old stem.
|2||It is light coloured.||Heartwood is dark
|3||Living cells are present.||Living cells are absent.|
|4||Sapwood is the functional
part of the secondary
xylem or wood.
|Heartwood is the
nonfunctional part of
|5||The tracherary elements
are not plugged by tyloses.
|The tracheary elements
are plugged by tyloses.
|6||Tracheary elements do not
possess any deposition in
|Tracheary elements have
deposition of tannins,
resins, gums, etc.
|7||Sapwood or albunum is
|Heartwood is heavier|
|8||It is less durable because it
is susceptible to attack by
pathogens and insects
|It is more durable due to
its little susceptibility to
the attack of pathogens
4. Secondary growth in dicotyledonous roots occurs by the initiation and activity of two secondary meristems– (i) vascular cambium and (ii) cork cambium (or phellogen). Vascular cambium derives from dedifferentiation of cells inner to primary phloem and pericycle cells outer to protoxylem. The cells of cambium strips (vascular cambium) divide repeatedly to produce new cells both towards inner as well as outer side. The cells produced towards innerside (centripetally) differentiate into secondary xylem elements and those produced towards outerside (centrifugally) differentiate into secondary phloem.
Multiseriate vascular rays are also produced from vascular cambium derived from pericycle cells i.e., ray initials. The primary xylem remains in its original position but the primary phloem is pushed towards outerside and crushed.
Cork cambium derives from dedifferentiation of pericycle cells. The cells of cork cambium (phellogen) divide to form cells of cork (phellem) towards outer side and secondary cortex (phelloderm) towards inner side. It results in the formation of outer protective covering consisting of multilayered cork, cork cambium and multilayered secondary cortex. These three layers make the periderm.