The outer layer of bone . is a thin membrane
is thick and hard
looks like a sponge
makes red blood cells

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.

you know that this symptom is misleading and quite often is related to: heart attack

a heart attack is a condition that occurs when the blood flow that transports oxygen to the heart muscle is damaged or cut off completely. the coronary arteries that supply the heart muscle with blood flow can be blocked by the accumulation of plaque. also, when the plaque within the heart artery breaks, it creates blood clot that can also hinder the blood flow. men that are over 45years of age and women that are over 55years of age are at risk of having a heart attack. the symptoms of a heart attack include chest discomfort, chest pain, coughing, and shortness of breath.