Transcript Plant_growth_1_

What is the activity of the meristems?
The cells carry out mitosis to produce new cells for plant
growth.
Are there any meristems in animals?
No as they grow all over
Name the two meristems and their position in a plant.
Apical meristem at the shoot and root tips
Lateral meristem in between the xylem and phloem called the
cambium
Label the diagram of the root tip.
S = apical meristem
R = region of elongation and vacuolation
Q = region of differentiation
P = region of permanent tissue
Name the cell process responsible for increase in the length
of the root.
Mitosis
Which meristem is involved in making annual rings?
Cambium found in the vascular bundles
Explain how annual rings are formed
Cambium becomes a complete ring
It produces new cells to the inside that differentiate into
xylem vessels
In the spring the xylem vessels have a larger diameter
(plants needs more water and nutrients to grow quickly)
In the summer the xylem vessels have a smaller diameter
as the plant requires less water and nutrients as it is
growth is slowing down.
This creates the annual rings
What can you learn about the plant from the
annual rings?
Age – number of years old
Count the annual rings in the diagram below
3 annual rings of xylem so 3 years old
Compare the powers of regeneration in angiosperms and
mammals.
Animals have poor powers of regeneration and plants
(angiosperms) have extensive powers.
Shape of annual plant
Decrease in mass initially as the seeds uses the starch food
store
Increase in mass as it produces food by photosynthesis
Growth starts to decrease as it dies off
Shape of the growth of a tree
Within one years there is more growth in spring and summer
and less growth in autumn and winter.
Human growth curve
Birth to 2 years there is a growth spurt (quick growth)
Then a steady growth period occurs
Second growth spurt – adolescent spurt
Insect growth curve between A and B
It loses the exoskeleton and the insect can grow
Step affect is produced because there is no growth when the
insect has developed an exoskeleton (lots of protection but no
growth)
.