6.4 organisation and specialisation of cells
General information
levels of organisation in multicellular organisms
specialised cells -> tissues -> organisms -> organ systems -> whole organism
cells become differentiated meaning they are specialised to carry out very specific functions
four main categories of tissues in animals
Muscle Tissue
Connective Tissue
Epithelial Tissue
Nervous Tissue
different tissues in plants
epidermis
vascular
an organ system is a number of organs working to together to carry out a major function
Specialised Animal Cells
Specialised Plant Cells
cell types
Erythrocytes - Red Blood Cells
Neutrophils - type of white blood cell
Sperm Cell - Male Gametes
Cell Types
Palisade Cell
Root Hair Cells
Guard Cells
Flattened biconcave shape increases their surface area to volume ratio so there is more area for oxygen to diffuse in and out, so they can more easily gain and release oxygen at certain points in the body
not many organelles so there is more room for oxygen and carbon dioxide
multi lobbed nucleus allows them so squeeze through gaps to get to the site of the infection
cytoplasm contains more lysosomes used to attack pathogens
more mitochondria so provide more energy to swim to egg
tail/flagellum to allow movement to get to the egg
acrosome on the head digests the protective layer of the egg to allow for fertilisation
Rectangle shape allows for them to be packed closely together to form a continuous layer
thin walls allow for easier diffusion (increases diffusion)
large vacuole maintains turgor pressure to keep shape
can move within the cytoplasm in order to absorb more light
long extensions to increase surface area to ensure the maximum uptake of water and minerals from the soil
form small openings (stomata) which allow for exchange of carbon dioxide and oxygen (necessary for photosynthesis)
when water is lost they become less swollen and change shape to prevent more water loss