Answer:
cellular membranes
Explanation:
Cellular membranes are selectively permeable because they allow only certain molecules to cross into and out of the cell. The phospholipid bilayer is a selectively permeable membrane that surrounds all biological cells. The movement of molecules across the cell membrane bilayer can occur by passive transport (does not require energy) or active transport (requires energy). For example, water molecules pass passively through the cell membrane (passive transport), while other molecules pass through transmembrane proteins against a concentration gradient (active transport).
Viruses enter human body like an invader and uses the living cells to replicate causing infections in the cell or can damage it.
Explanation:
The attacks of viruses on the body of living organisms is compared with a ‘sneak attack’ as they invade the body and enters into a living cell to replicate themselves. This may cause damage or bring about changes in the cell causing sickness and infections.
They can hide themselves on our body attacking sneakily to harm the immune system to fight the infection. This stealth infection can result in fever, damaging immunity, disorder etc.
I'm a carbohydrate and I'm useful for a fast source of energy.
Answer:
umm well I dont know to. be honest
