Plant Tissue (leaf Structure) Flashcards
What is leaf vein?
Water and salts enter the leaf via the xylem. Sugar made by photosynthesis passes out of the leaf via the phloem.
What is guard cells?
Stomata open and close in response to changing conditions, such as light intensity, humidity, and carbon dioxide concentration.
What is lower epidermis?
The lower epidermis is a layer one cell thick, like the upper epidermis.
It contains pores called stomata (singular stoma). Each stoma is made is made up of a pair of guard cells.
The stomata allow gases and water vapour to diffuse in and out of the leaf.
What is spongy mesophyll layer?
This layer consists of irregularly shaped cells with large air spaces between them and looks like a sponge when seen under a microscope.
The cells have fewer chloroplast than the palisade cells since the light intensity is less.
What is palisade mesophyll layer?
Palisade cells have a cylindrical shape. This helps the light to penetrate into the leaf.
Chlorophyll is contained in chloroplasts. Palisade cells have more chloroplasts than other cells in the leaf.
The chloroplasts can move within the cell to regions where the light intensity is greatest.
What is upper epidermis?
The upper epidermis is one cell thick and covers the leaf like a skin. The cuticle is a waxy layer which protects the leaf against disease organisms such as parasitic fungi.
The cuticle is waterproof and helps prevent water loss by evaporation.
What is lower epidermis?
The lower epidermis is a layer one cell thick, like the upper epidermis.
What does the lower epidermis contain?
It contains pores called stomata (singular stoma). Each stoma is made is made up of a pair of guard cells.
What does the stomata allow?
The stomata allow gases and water vapour to diffuse in and out of the leaf.
What does the spongy mesophyll layer consists of?
This layer consists of irregularly shaped cells with large air spaces between them and looks like a sponge when seen under a microscope.
What do the cells have?
The cells have fewer chloroplast than the palisade cells since the light intensity is less.
What kind of shape do palisade cells have?
Palisade cells have a cylindrical shape.
What does it help?
This helps the light to penetrate into the leaf.
What is chlorophyll contained in?
Chlorophyll is contained in chloroplasts.
What cells have more chloroplasts than other cells in the leaf?
Palisade cells have more chloroplasts than other cells in the leaf.
