Biology Questions

The olfactory system is the only system in which the receptors send their signal directly to the higher brain and bypass the thalamus, which normally acts as a filter for the processes of the lower brain.

Membrane bound organelles are not found in the cells of Prokaryotes whereas Eukaryotes have nucleus and membrane bound organelles.

For example : Bacteria is prokaryotic organism with lack of nucleus and membrane bound organelles whereas fungi is a eukaryotic with nucleus and membrane bound organelles.

Veins are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart.

Veins are less muscular than arteries and are often closer to the skin. There are valves in most veins to prevent backflow.

A pulse can be detected most easily in Arteries as they are under much greater pressure than veins because they are carrying blood away from the heart which is the pumping machine to force blood to move to all of the body.

Every time the hear contracts, it can be felt in an artery where a surge of blood has just been forced.

A capillary is too small to feel a pulse and a lacteal is part of the lymphatic system found in the small intestine.