9.3 Growth In Plants

Question 1

Angiosperm tissue types (flowering plants)

Answer 1

Dermal tissue - outer protective layer (prevents water loss and pathogens)

Ground tissue - thin walled cells used for storage and photosynthesis

Vascular tissue - xylem and phloem

Meristematic tissue builds all tissue

Question 2

Angiosperm organs

Answer 2

Root - absorbs minerals and water

Leaves - photosynthesis (6 structure parts)

Stem - raises leaves up for more sunlight, (6 structure parts)

Question 3

Stem structure

Answer 3

All come together to form vascular bundle

Question 4

Leaf structure

Answer 4

Question 5

Plant growth

Answer 5

Cells divide from the lateral and apical meristems through mitosis

Lateral = vascular and cork cambiums (grows out and thick)

Apical = shoot and root (Taller and longer roots)

Question 6

Lateral meristem growth (5 phases)

Answer 6

Question 7

Result of removal of bark and vascular cambium around the tree

Answer 7

New Phloem and Xylem cannot be produced and tree dies.

Cork is able to be taken from the tree because the cork cambium remains protecting the xylem and phloem. But can still produce more cork

Question 8

Plant hormones

Answer 8

Auxins = initiates growth of roots, fruits and leaves
- Prevents axillary bud growth

Cytokinin = produced in root to promote axilliary bud growth
- Inhibits root growth

Gibberellin = promotes elongation and seed germination

Question 9

Plant growing towards light

Answer 9

1. Phototropins in plant tip detect more light on one side of plant than the other
2. Phototropins change shape
3. PIN3 proteins are produced
4. PIN3 proteins regulate Auxin efflux
5. Auxin moved to shadier side
6. Plant grows more on shadier side causing the plant to bend towards the light

Question 10

Tropism

Answer 10

Growth in a specific direction due to external stimuli

Question 11

Gravitropism

Answer 11

Statoliths fall within the cell due to gravity.

PIN3 proteins direct auxin to bottom of cell.

Auxins then promote growth in roots downwards