Answer:
Bacteria like E coli, streptococcus
Viruses like Influenza and HIV
Parasites like malaria
Correct answer: A) Extension
Extension is a physical position that occurs when angle between the bones and the limbs of joint increases.
It takes place when there is a contraction of muscles and bones move the joint from a bent to a straight position, it is opposite of flexion, in which the angle between the bones and the limb at the joint decreases.
Example: During straightening of the leg, the angle between the tibia and femur increases, which shows extension has taken place.
A viroid is an infectious piece of RNA without a capsid. A viroid is an infectious RNA molecule, which is similar to a virus, however, not quite the same thing. It's smaller than a virus and has no capsid. It is a coiled "naked" RNA molecule that can affect a cell. An example of human disease that is known to be caused by Viroid is hepatitis D.
