Cholesterol
The animal plasma membrane is a layer of phospholipids that is entwined with cholesterol and proteins. Cholesterol makes up a small part of the cell membrane's mass and it is present in every cell of the body. Cholesterol maintains the integrity of the cell membrane. It assists in the immobilization of the outer surface of the cell membrane and it reduces the permeability of the membrane to most biological molecules. Cholesterol also perform roles in cell signaling, maintaining fluidity and protecting important proteins in the membrane.
It depends on the organism, they all vary, they can reach up to 90% but I’m not sure so pick C:70%
16 neutrons are present in the most abundant isotope.
Explanation:
Phosphorus has 18 isotopes. The most common isotope has mass number (no. of protons 15+ no. of neutrons 16=) 31 .
Answer:
A. Integumentary system
Explanation:
The integumentary system consists of the skin,hair and nail. This system consists of the largest organ in the body. The skin helps in protection against pathogens by shielding the internal body system from external objects.
The skin also helps in Vitamin D production through sunlight.
It also helps to prevent dehydration through regulation of water loss.