Cell wall - made of cellulose which supports cell
Vacuole - cell sap
Chloroplast - Photosythesis occurs, contains chlorophyll
Nucleus - contains genetic info which control activities of cell
Cytoplasm - chemical reactions happen, contains enzymes.
Mitochondria - Respiration takes place here
Ribosomes- proteins are made.
In a leaf:
the waxy layer- stops water escaping
upper epidermis- transparent layer to let light through
palisade mesophyll- cells contain chloroplast trap light.
spongy mesophyll- has air spaces to allow gases in and out
xylem and phloem- tubes bring water and take away glucose
lower epidermis- layer with stomata (allow gases to diffuse in and out of leaf)
Animal, Yeast and Bacteria Cells
Nucleus- contains genetic material, controls activities of cell
Cytoplasm- chemical reactions happen, contains enzymes
Ribosomes- proteins are made
Types of Fossils and Extinction
Gradual Replacement - By Minerals replacing bones ect. Form rock like substance.
Casts and Impressions - In places like clay and mud.
Preservation - In environments where no decay can happen.
Causes for Extinction:
The Environment Changes too quickly.
Speciation (new species develops)