1st -When cells are small, the movement of food and waste can be efficiently handled by the cell membrane
No this is not valid, bacteria and other Arachae do not possess membrane bound organelles like mitochondria and or chloroplasts, but use transport and enzymatic proteins across the cell membrane to carry out essential functions.
Along with having polypeptide makers, as ribosomes.
False it does pose a threat to human life
Answer: The answer is the last option, Backflow of blood through a defective valve.
Explanation: Hypotension causes high blood pressure, and the other two options are not related to heart murmurs. A hear murmur is when the blood isn't flowing in the right direction causing the hear to beat irregularaly.
