On week 4, I learn about the cell theory, prokaryotes, virus, prions and viroids. there are 3 basic cell theory which are all living organisms are made up of one or more cells, cell is derived from pre-existing cell by cell division and cell is the basic unit of structure & function in living organisms.There are addition of 3 for modern cell theory.
PROKARYOTES
In prokaryotes it has cell wall, capsule, cell membrane, nucleoid region (DNA), flagella and pili
VIRUS
-has genetic material (DNA & RNA)
-reproduce inside host cell
-nucleic acid surrounded by protective protein coat called capsid
some virus surrounded by outer membrane layer called an envelope made up of lipid and protein.
-Virus reproduce in 2 ways :
1) Lytic Cycle 2) Lysogeny Cycle
PRIONS
-an infectious agent
-specific protein that prion was composed is Prion Protein (PrP)
-PrP found in infectious material
VIROIDS
-small circular RNA without protein coat
-contain 20 nucleotides
-infect plants