What is photosyntesis?
this word can be separated to make two smaller words
Did you know that trees and plants can make their own food, but animals can't?
To make food plants need
CO2 from the air passes through small pores in the leaves, which are called stomata
Water is absorbed by the roots and passes through vessels in the stem on its way to the leaves
Sunlight is absorbed by a green chemical in the leaves
Photosynthesis takes place in the leaves of plants. The leaves are made up of very small cells. Inside these cells are tiny structures called
each chloroplast contains a green chemical called
which gives leaves their green colour
Let's sum up the knowledge about photosyntesis
plants need carbon dioxide, water and sunlight to make their food
the food they make is called glucose
in addition to glucose, plants also produce oxygen
Why is photosynthesis important?
1. provides food and energy for animals
2. produces oxygen and removes carbon dioxide from the air
What did you learn from previous labwork in Spain?
Today we're going to continue with this topic and the aim of todays labwork is
The epidermis structure of the leaf
Vocabulary you have to know
monocots - monocotyledons - they have only one cotyledon in embryo, leaf veins are parallel, roots - taproot system (grains, daffodils, banana, onions, grass...)
dicots - dicotyledons - dicot embryo has two cotyledons, leaf veins are reticulated (branched), fibrous roots (legumes, lettuce, tomato...)
stomata - is a pore, found in the epidermis of leaves, that is used to control gas exchange
Stomata open and close to allow the intake of carbon dioxide and the release of oxygen.
Stomata open when there is sunlight. Therefore, stomata are usually open during the day and closed at night
Dicotyledons usually have more stomata on the lower epidermis than the upper epidermis.
Monocotyledons have the same number of stomata on the two epidermes.
Structure of the leaf
Internal structure of a leaf
material tools
PROCEDURE
1. get the upper and lower part of the leaf epidermis
2. fold the leaf and catch and loose part of epidermis
3. replace this part of epidermis by use of tweezer
4. drip a drop of water on the glass microscope slide
5. move the part of epidermis on the glass microscope slide and cover with cover glass - prepare microscope preparation
6. observe with microscope
TASKS
1. find out the structure of the upper and lower epidermis of monocots and dicots and draw it
2. find out and describe internal structure of the leaf and write the names of marked parts in the picture
3. find out where are stomata situated and write what is their importance, try to draw stomata
4. conclusion - explain the difference between monocots and dicots regard to the leaf epidermis and describe the layout of the cells in leaf blade and point out the stomata importance