organisation of cells Flashcards
hierarchical structure of cells
organelles-cells-tissues-organs-systems-organisms
what are unicellular organisms
a single cell
can be either prokaryotic or eukaryotic
example include bacteria and protista
responsible for all its own life processes
only have ribosomes
may contain cell membrane, cytosine, ribosomes and some sort of genetic material
what are colonial organisms
made up of a group of identical single called organisms
all individuals are capable of carrying out their own function
examples include volvox, coral or jellyfish
what are multicellular organisms
made up of many different types of cells
they cannot live independently of each other
what are the differences between unicellular organisms
- single called organisms
- interdependent
- simple cells, little specialisation
- reproduce asexual (identical offspring)
what are the differences between colonial
- group of identical cells
- some cooperation between cells. independant as individual cells
- slightly more specialised than unicellular
- reproduce asexual
what are the differences between multicellular
- large number of differentiated cells
- cells are dependant
- highly specialised
- asexual-mitosis
sexual-meiosis
similarities between unicellular, multicellular and colonial
- they are all composed of cells
- they all contain genetic material
- they all possess ribosomes, cell membrane, cytoplasm
where do all specialised cells come from
stem cells
what is cell specialisation
it refers to the particular functions that the cell does
what is differentiation
the process that a stem cell goes through to become specialised
what happens when organisms are growing and developing
their cells (except gametes) are constantly dividing by mitosis
undifferentiated cells for mammals
stem cells
undifferentiated cells for plants
meristematic cells
