Chapter 29.3- Secondary Growth

Question 1

Why is the growth in plant diameter important? What two functions does it serve:

Answer 1

1. it strengthens the stem
2. increases the capacity of vascular plants

Question 2

What is primary growth?

Answer 2

plant growth in length meristems are responsible for it

Question 3

What is secondary growth?

Answer 3

is the increase in plant diameter

increased lateral stems.

Question 4

What is a lateral meristem?

Answer 4

grows the width of a plant

Question 5

What are the ways in which later meristems differ from shoot apical meristems?

Answer 5

• Lateral stems surround the stem vs. the tip
• Later stems grow diameter vs. length
• Lateral meristems become larger over time vs. staying the same size

Question 6

What are the two types of lateral meristems?

Answer 6

Vascular cambium cambia: responsible for diameter increase and is the sour of phloem and xylem

Cork cambium: responsible for creating an outer protective layer after primary growth stops.

Question 7

Where does vascular cambium cells form in xylem and phloem cells?

Answer 7

in between the procambial cells and parenchymal cells located in vascular bundles

Question 8

How can we differentiate what becomes secondary xylem or secondary phloem ?

Answer 8

Secondary xylem: inside of the vascular cambium (creates wood) easy to pull apart

Secondary phloem: those on the outside vascular cambium ( Bark)

Question 9

How does the vascular cambium create new secondary xylem cells?

Answer 9

newly formed cells push the vascular cambium outwards the vascular cambium adds new cells to increase perimeter.

Question 10

How does the vascular cambium create a secondary phloem?

Answer 10

the vascular cambium expands and breaks the phloem and creates a new secondary phloem

Question 11

Where is water producing xylem located vs non producing xylem?

Answer 11

Sapwood: is where water producing xylem is

Heartwood: in the center of the tree and does not produce water darker in color due to chemicals

Question 12

What information does the growth ring of a tree tell you?

Answer 12

the age of a tree and envoriment of the tree

Question 13

What information does the growth ring of a tree tell you? compare wide growth ring to narrow

Answer 13

the age of a tree and environment of the tree
Wide growth ring: more desirable conditions

Narrow growth rings: less desirable conditions

Question 14

How does cork cambium form?

Answer 14

stems from cortex cells that actively divide drifting further from the phloem. As it no longer has access to carbohydrates it creates a second phloem.

Question 15

What are the structural functions and components of cork?

Answer 15

• suberin coats the outside of cork which protects the cells from pathogens and mechanical damage. ( hard for oxygen to enter)
• lenticels is the outer bark that allows oxygen to enter the cell

Question 16

What are two examples that show the diversity of angiosperms wood?

Answer 16

Fibers: they are narrow cells with thick walls they help the plant grow taller

Vessel elements: are extremely wide cells that transport water they can grow bigger than tracheid bc of fiber support.