Answer: chain link fence
Peptidoglycan could be found in high number on gram positive cell walls. The structure of peptidoglycan looks like a cross link which makes it sturdy, so rain coat would be false. It is not an impenetrable brick wall because it still allow some ion and food pass through it. Sugar candy coat sounds good but chain link fence would be better.
HIV tests are used to detect the presence of the human immunodeficiency virus
(HIV) the virus that causes acquired immunodeficiency syndrome (AIDS) in serum, saliva , or urine such tests may antibodies, antigens, or RNA .
Nondisjunction - in nondisjunction, the chromosomes fail to separate at a proper state due to meiosis.
