5.2 Plants grow

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 1

Are you ready?

- Put your phone in your locker

- Coats are on the coat rack or in your locker

- Bags are off the table

- Take off your hat or hoodie

- Books and laptops are on the table

- Did you do your homework?

 

5.2 Plants Grow

Learning objectives 

You will learn how a seed becomes a plant, how the plant develops further, and how a tree grows.

Quiz!

15 seconden per vraag!

Sequoia

• Very large diameter (one of the largest actually)
• North America
  

You need more than fifteen people to make a circle around the stem.

How tall do you think a sequoia can grow?

1. 25 m
2. 50 m
3. 100 m
4. 200 m

Is it a herbaceous or woody plant?

1. Herbaceous
2. Woody

What is germination?

What grows first in a plant?

1. Roots
2. Stem
3. Leaves

What is the difference between growth and development?

How does a plant grow from a seed?

Flowers become fruits!

Seed coat = outer layer that protects the germ and cotyledons.

Cotyledons (ko·tuh·lee·dnz) = the first pair of leaves with reserve food for the germ.

Germ = the very young plant that is inside a seed.

Germinating

1. First, the seed coat absorbs water.
   
2. This causes the cotyledons to swell and the seed coat to burst open.
   
3. Then the roots start growing.
4. Then the stem and the leaves grow.
   

Why do the roots start growing before the leaves?

Growth

Cell division and cell growth

Meristems = the far ends of stems and roots; here, the plant forms new cells

Development

Branch

terminal bud = a bud at the end of a branch, from which tree branches get longer

lateral buds = buds on branches from which new side branches grow  

bud scales = scales that protect the bud on a branch against the cold and insects

bud scale scar = a ring-shaped scar on a branch, at the spot where the bud scales fell off a terminal bud (one year).

Stem

Growth layer = New wood cells are formed there in spring and summer.

Annual growth ring = layer of wood cells that is formed in one year, (oldest in the middle)

• Light brown = Wood cells that develop during spring (large and thin cell walls).
  
• Dark brown = Wood cells that develop during summer (smaller and thicker cell walls).
  

Information about the tree (age, drought, pest, growing at an angle)

Why does a root grow downwards?

• gravity
• starch granules sink down
  
• stem responds to sunlight

What?	Make 5.2: assignments 4,5,8-10,12,14
How?	In your workbook (or computer). Use the information from your textbook.
Help?	You may gently consult with your neighbor. Raise your hand if the two of you can't figure it out together.
Time?	10 minutes
Finished?	Start to work on your research paper.
Product	You have practiced 5.2.

Let's discuss the lesson!

Don't pack your bags yet!

What did you learn today?

When de bell rings:

- Pull up your chairs

- Don't forget your phone