First 534 words of the document:
Cell Organisation - small ribosomes when compared to Some cells remain undifferentiated such
eukaryotic cells as the parenchyma cells in plants which
Animal and Plant Cells: - cell wall is made up of murein act as packing cells.
Plant cells contain;-
- Plasmodesmata Comparison: Tissues are groups of cells which have all
- Chloroplasts Prokaryotes- naked nucleus, earliest life differentiated in the same way, and so work
- Large vacuoles form, small ribosomes, no membrane together to fulfil a common role. Example
- Cellulose cell wall organelles, murein cell wall. would be bi-ceps muscle.
- no centrioles Eukaryotes- true nucleus, evolved from
Animal cells contain;- prokaryotes, membrane organelles, cellulose Organs are a collection of different tissues
- centrioles cell wall. that work together to fulfil a common role.
- small temporary vacuoles Example would be an eye.
- No Plasmodesmata Viruses:
These are so small that they can only be Systems are a group of organs working
- No chloroplasts together to fulfil a common role. Example
seen with an electron microscope. Each viral
- No cell wall would be the digestive system.
cell consists of a nucleic acid which can
either be DNA or RNA. The nucleic acid is
There are two types of cells which are known Organisms are made up of man systems
contained in the caspid or protein coat.
as Eukaryotic cells which are found in working together. Example would be human
Viruses which infect animals/plants contain
animals, plants, fungi and some algae. beings.
RNA while viruses which infect bacteria
Prokaryotic cells are found in blue-green
algae and bacteria.
Viruses have no organelles or cytoplasm, so
can they really be cell at all?
It is assumed that these cells evolved from
They only contain a nucleic acid rather than
prokaryotic cells. The characteristics are;-
the DNA arranged in chromosomes. It is only
- a true nucleus which as DNA when they invade another organism, known
arranged in chromosomes and a
as the host, can they reproduce as they can
use the host's metabolism.
- contains cell organelles *outside a host a virus exists as an inert
- large ribosomes when compared to virion*
prokaryotic cells T2 bacteriophage is a virus that you need to
- and the plant eukaryotic cells have a know. It infects bacteria, and so contains
cellulose cell wall DNA, and it only infects the bacterium E-Coli.
Prokaryotic Cells: Multicellular Organism Organisation:
These kinds of cells are very simple, and are Higher animals and plants are made up of a
probably the earliest life form on Earth. large variety of cells.
The characteristics include;- These cells are specialized in order to carry
- no true nucleus that isn't contained in out specific roles in the body.
a membrane and the DNA lies free in
- no membrane organelles