Secondary Thickening Flashcards
What is secondary thickening?
The process by which plants increase the diameter of their stems and roots through the production of additional vascular tissues.
Which type of cells primarily contribute to secondary thickening?
Cambia, specifically vascular cambium and cork cambium.
True or False: Secondary thickening occurs in all plant types.
False, it primarily occurs in dicotyledons and gymnosperms.
What is the main function of the vascular cambium?
To produce secondary xylem (wood) and secondary phloem.
Fill in the blank: The outermost layer of bark is known as __________.
periderm.
What tissues are formed by the cork cambium?
Cork cells and phelloderm.
Multiple Choice: Which of the following is NOT a component of bark? A) Cork B) Cortex C) Xylem D) Phelloderm
C) Xylem.
What is the role of cork cells in plants?
To provide protection and reduce water loss.
True or False: Secondary phloem is responsible for the transport of water.
False, it transports nutrients and sugars.
What happens to the primary phloem during secondary thickening?
It gets pushed outward and may eventually be crushed or sloughed off.
Fill in the blank: The vascular cambium is a type of __________ meristem.
lateral.
What are the two main types of cells produced by the vascular cambium?
Tracheids and vessel elements for xylem; sieve elements and companion cells for phloem.
What is the significance of secondary thickening in woody plants?
It provides structural support and allows for increased height and girth.
Multiple Choice: Which of the following layers is formed last during secondary growth? A) Secondary xylem B) Cork C) Secondary phloem D) Phelloderm
B) Cork.
True or False: Bark is primarily made up of living cells.
True, the inner bark (secondary phloem and phelloderm) consists of living cells.
What is the main component of the periderm?
Cork (phellem).
Fill in the blank: The process of cork formation is known as __________.
cork cambium activity.
What is a common feature of trees that undergo secondary thickening?
They develop a distinct bark layer.
Multiple Choice: What type of growth do monocots primarily exhibit? A) Primary growth B) Secondary growth C) Both A and B D) None of the above
A) Primary growth.
What is the role of the phellogen?
To produce cork cells and contribute to the formation of the periderm.
True or False: The secondary growth process is reversible.
False, it is not reversible.
What is the primary substance that composes the cell walls of cork cells?
Suberin.
Fill in the blank: The __________ is the layer of cells just inside the cork that can perform photosynthesis.
phelloderm.
What happens to the vascular cambium as a plant matures?
It continues to divide and produce new layers of xylem and phloem.
Multiple Choice: Which of the following is NOT a characteristic of secondary growth? A) Increased diameter B) Formation of new leaves C) Production of secondary xylem D) Development of bark
B) Formation of new leaves.
What is the relationship between secondary thickening and tree rings?
Tree rings are formed by the annual growth of secondary xylem produced by the vascular cambium.
