Lecture 12

Question 1

Indeterminate growth

Answer 1

most plants experience this and means that they continue to grow for the duration of their life. allows plants more exposure to sunlight, soil, and air

Question 2

Angiosperms characterized according to life cycle duration

Answer 2

• annuals
• biennials
• perennials

Question 3

Annuals

Answer 3

complete lifecycle in one year of less (crops)

Question 4

Biennials

Answer 4

complete lifecycle in 2 years (beets/carrots)

Question 5

Perennials

Answer 5

live and reproductive for many years (trees/shrubs)

Question 6

Plant growth made possible by tissues called..

Answer 6

meristems

Question 7

Meristems

Answer 7

consist of cells that divide frequently generating more cells. some of these new cells remain in the meristem and continue to divide while other differentiate being incorporated into the tissue of plant

Question 8

Apical meristems

Answer 8

located at tips of roots and buds of shoot. enables roots to push through the soil and shoots to increase exposure to life/CO2

Question 9

Primary growth

Answer 9

cell division here produces new cells allowing the plant to grow in length

Question 10

Root cap

Answer 10

tip of root covered by this which protects the cells of the apical meristem which are actively dividing

Question 11

Growth in length occurs just behind the root tip with 3 areas of distinct cells

Answer 11

• zone of cell division
• zone of elongation
• zone of maturation

Question 12

Zone of cell division

Answer 12

contains the cells of the root apical meristem and cells that derive from it. new cells of the root are produced here (root cap cells)

Question 13

Zone of elongation

Answer 13

root cells here elongate (10x). pushes the root tip hurter into soil, cells lengthen and don’t expand because cellulose finer arrangement, cells take up water and the cellulose fibres separate expanding like an accordion

Question 14

Zone of differentiation

Answer 14

all 3 plant tissues complete their development here. cells in the vascular cylinder differentiate into primary xylem and primary phloem. occurs because of differential gene expression

Question 15

Secondary growth

Answer 15

woody plants continue to grow in girth once primary growth is complete

Question 16

Lateral meristems

Answer 16

secondary growth occurs because of activity in these stems. arranged into cylinders called vascular cambium and cork cambium

Question 17

Vascular cambrium

Answer 17

cylinder of meristem cells one cell thick between the primary xylem and primary phloem

Question 18

Secondary growth adds..

Answer 18

layers of vascular tissue on either side of the vascular cambrium