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)

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