New News Biology #23

The Structure of Leafs

Plant Organization (from small to big):

Smaller cells

Tissues

Organs

Organ systems

Plant

Example: Leaf (organ) + Stem (organ) + Roots (organ) = Transport substances (organ system)

The Structure of a Leaf (from bottom to up):

The stoma are located in the lower epidermis, which allow the carbon dioxide in and water out

The carbon dioxide travels up, through the spongy mesophyll. Also located here is the phloem, which is a tube that carries stuff

The carbon dioxide then travel to the palisade mesophyll, where most of the photosynthesis happen. That is also why the cells at this layer contain a lot of chloroplasts

Above the palisade mesophyll is the upper epidermis.

Stoma Adaptations (concluded into a short rhyme):

Sensitive to light, closes at night

If water too much, turgid (open up)

If water too little, flaccid (closed down)

And all that is to conserve the water

Meristem Tissues = able to differentiate into loads of other tissues

These are mainly located at the growing tips of stems & roots, which enables the growth of the plant.