1. The vascular cambium activity is
a) More on inner side than outer
b) More on outer side than inner
c) Equal on outer and inner side
d) None of these
Explanation: The vascular cambium activity is more on inner side than outer
2. The following will not happen during secondary growth by cambium ring:
a) Secondary xylem produced is more than secondary phloem.
b) Primary and secondary phloem is crushed due to continued formation and accumulation
of secondary xylem.
c) Primary xylem remains more or less intact in or around centre.
d) The cells cut off towards pith mature into secondary phloem and cells cut off towards
periphery mature into secondary xylem.
Explanation: The cells cut off towards pith mature into secondary phloem and cells cut off towards periphery mature into secondary xylem.
3. During secondary growth all occur except
a) Secondary medullar rays forms
b) Phloem crushed
c) Primary phloem forms
d) Secondary xylem forms
Explanation: Primary phloem forms
4. The activity of cambium is under control of
a) Physiological factor
b) Environmental factor
c) Both (a) and (b)
d) None of these
Explanation: Both (a) and (b)
5. Select the total number of correct statements from the following:
(1) In spring season cambium is active and produces a large number of xylary elements
having vessels with wider lumen.
(2) The spring wood is also known as early wood.
(3) In winter, the cambium is less active and forms few xylary elements having narrow
vessels this is called autumn wood or late wood.
(4) The spring wood is lighter in colour and has lower density.
(5) Autumn wood is darker and has higher density.
(6) Annual ring (autumn wood and spring wood) used to estimate the age of plant.
a) 3
b) 4
c) 5
d) 6
Explanation: 6
6. In older trees, the greater part of secondary xylem is dark brown due to the deposition of
a) Tannins and resins
b) Oil and gums
c) Aromatic substance and essential oil
d) All of these
Explanation: All of these
7. The dark brown deposition of organic compound in heartwood will make it
a) Hard
b) Durable
c) Resistant to microbes and pest
d) All of these
Explanation: All of these
8. Heartwood contains
a) Live lignified element
b) Dead highly lignified element
c) Live non-lignified element
d) Dead non-lignified elements
Explanation: Dead highly lignified element
9. The function of heartwood is
a) Conduction of water
b) Conduction of mineral
c) Conduction of food
d) Mechanical support
Explanation: The function of heartwood is Mechanical support.
10. Peripheral region of secondary xylem, which is light in color is known as
a) Heartwood (duramen)
b) Sapwood (alburnum)
c) Spring wood
d) Autumn wood
Explanation: Sapwood (alburnum)