2A-2B LEVELS OF ORGANISATION + CELL STRUCTURE

definition of organelles

a component within a cell that carries out a specific task

definition of cells

the basic structural and functional units in a living organism

definition of tissues

a group of cells of similar structure working together to perform a particular function

definition of organs

a group of different tissues working together to perform a particular function

definition of organ systems

a group of organs with related function working together to perform body functions within the organism

nucleus structure/function

• contains genetic material in chromosomes which control how cells grow and work

• controls cell division

cytoplasm structure/function

• supports cell structures

• site of many chemical reactions

• contains water + many solutes

cell membrane structure/function

• holds the cell together

• controls substances entering and leaving the cell

cell wall function/structure

• gives the cell extra support

• defines cell shape

chloroplasts structure/function

• site of photosynthesis, providing food

• the chlorophyll pigments absorb light energy needed for the reaction to occur

vacuole structure/function

• contains cell sap

• used for storage of certain materials

• helps support cell shape

mitochondria structure/function

• site of aerobic respiration, providing energy for the cell

ribosomes function/structure

• site of protein production in protein synthesis

what is cell differentiation

• the process by which a cell changes to perform a specific function

• during differentiation, certain genes get activated or inactivated

• the cell then produces different substances or develops into a different shape

benefits of stem cells

• great potential to treat a wide variety of diseases, some already done successfully

• organs developed from a patients own stem cells will not be rejected + no wait time

risks of using stem cells

• stem cells cultured in labs could be infected with viruses which are then transferred to the patient

• cultured stem cells could accumulate mutations which could lead to cancer cells.

• low number of stem cell donors

what is a stem cell

an undifferentiated cell of an organism capable of infinitely dividing. it can be used to repair damaged orans by growing new tissues, using the patient’s genetic information.