1. What is the primary function of cork cambium in plants?
a) Transport of nutrients
b) Photosynthesis
c) Production of secondary xylem
d) Formation of periderm
Answer: d) Formation of periderm
Explanation: Cork cambium produces cork (phellem) on the outer side and phelloderm on the inner side, forming the periderm that replaces the epidermis during secondary growth.
2. Cork cambium originates from which type of cells?
a) Meristematic cells
b) Parenchyma cells
c) Collenchyma cells
d) Sclerenchyma cells
Answer: b) Parenchyma cells
Explanation: Cork cambium is a lateral meristem that typically arises from dedifferentiated parenchyma cells in the cortex during secondary growth.
3. What is another name for cork cambium?
a) Vascular cambium
b) Phellogen
c) Pericycle
d) Xylem
Answer: b) Phellogen
Explanation: Cork cambium is also called phellogen, which is responsible for producing phellem (cork) and phelloderm.
4. Which part of the periderm is impermeable to water and gases?
a) Cork (phellem)
b) Phelloderm
c) Cortex
d) Epidermis
Answer: a) Cork (phellem)
Explanation: Cork is composed of suberized cells that are impermeable to water and gases, providing protection and preventing water loss.
5. In which plants is secondary growth most prominent?
a) Monocots
b) Dicots and gymnosperms
c) Bryophytes
d) Pteridophytes
Answer: b) Dicots and gymnosperms
Explanation: Secondary growth occurs in dicots and gymnosperms due to the activity of vascular and cork cambium.
6. Which compound in cork makes it resistant to decay?
a) Cellulose
b) Lignin
c) Suberin
d) Pectin
Answer: c) Suberin
Explanation: Suberin is a waxy substance in the cork cell walls that makes them water-resistant and decay-resistant.
7. What is the role of lenticels in the cork?
a) Photosynthesis
b) Gas exchange
c) Water absorption
d) Mechanical support
Answer: b) Gas exchange
Explanation: Lenticels are small openings in the cork that allow gas exchange between the internal tissues and the external environment.
8. What happens to the epidermis during secondary growth?
a) It thickens
b) It is replaced by the periderm
c) It forms secondary xylem
d) It forms lenticels
Answer: b) It is replaced by the periderm
Explanation: The epidermis is replaced by the periderm, which is formed by the cork cambium during secondary growth.
9. Which of the following is NOT a part of the periderm?
a) Cork (phellem)
b) Phelloderm
c) Vascular cambium
d) Cork cambium (phellogen)
Answer: c) Vascular cambium
Explanation: The periderm includes cork, phelloderm, and cork cambium, while vascular cambium is involved in the production of secondary vascular tissues.
10. Cork cambium is an example of which type of meristem?
a) Apical meristem
b) Intercalary meristem
c) Lateral meristem
d) Primary meristem
Answer: c) Lateral meristem
Explanation: Cork cambium is a lateral meristem responsible for secondary growth, producing tissues that increase girth.
11. The cork cambium produces cork on the ______ side.
a) Inner
b) Outer
c) Both inner and outer
d) None
Answer: b) Outer
Explanation: Cork cambium produces cork cells on the outer side and phelloderm on the inner side.
12. Suberin in cork cells serves to:
a) Store food
b) Transport water
c) Provide rigidity
d) Reduce water loss
Answer: d) Reduce water loss
Explanation: Suberin is hydrophobic and prevents water loss, protecting the plant from dehydration.
13. Secondary growth in plants is absent in:
a) Dicots
b) Gymnosperms
c) Monocots
d) Angiosperms
Answer: c) Monocots
Explanation: Monocots typically lack secondary growth because they do not have vascular and cork cambium.
14. Phelloderm cells are generally:
a) Thick-walled and suberized
b) Thin-walled and living
c) Dead and lignified
d) Sclerotic
Answer: b) Thin-walled and living
Explanation: Phelloderm cells are parenchymatous, living, and thin-walled, aiding in storage.
15. What causes the formation of annual rings in trees?
a) Cork cambium activity
b) Seasonal activity of vascular cambium
c) Photosynthesis
d) Hormonal changes
Answer: b) Seasonal activity of vascular cambium
Explanation: Annual rings result from variations in vascular cambium activity during different seasons, not cork cambium.
