Cell Organisation:Prokaryote Cell Eukaryote Cell

Cell Organisation:Prokaryotes have a simple structure and probably the first life on Earth!

Eukaryotes probably evolved from prokaryote cells around 1000 million years ago!

Features:

Prokaryotic cells Eukaryotic cells

Bacteria and blue-green algae

Found in plants, animals, fungi and protoctists

No membrane bound organelles

Membrane bound organelles

DNA is free in the cytoplasm

DNA located on chromosomes

No nuclear membrane or E.R.

Distinct membrane-bound nucleus

Ribosomes are smaller Ribosomes are larger

Cell wall contains murein

Cell wall in plants is made of cellulose

Viruses:Cause a variety of infectious diseases in humans, animals and plants.Extremely small and can only be seen with an electron microscope.

Can be called ‘non cells’ as they have no cytoplasm, organelles and no chromosomes.

Exist as an inert ‘viron’ when outside a cell.

Take over a cell’s metabolism and multiply within the host cell.

Each virus particle has a core of nucleic acid surrounded by a protein coat called the capsid.

Most viruses found in animal cells and those attacking bacteria (bacteriophages) have the nucleic acid DNA.

Other animal and plant viruses contain RNA.

A widely studied virus is T2 phage, a bacteriophage, which infects the bacterium Escherichia coli (E. coli).

Differences Between Plant and Animal Cells:

Plant Cells Animal CellsCell wall No cell wallChloroplasts No chloroplastsLarge permanent vacuole Small, temporary vacuolesNo centriole CentriolePlasmodesmata No plasmodesmata