Explanation:
When a person opens the door, he or she uses 3 systems:
1. Nervous system: from the nervous system, neural instructions are generated through electrical impulses towards the muscles of the upper limb so that they make the necessary movements to open the door.
2. Muscular system: through the muscles of the trunk and the upper limb, it generates voluntary movement to open the door.
3. Skeletal system: the bones are the support of the soft tissues and the fulcrum of most of the skeletal muscles. In this sense, it serves as a support for the muscles of the trunk and the upper limb to carry out the movement of opening the door.
we can conclude that the correct answer is:
Answer:
1. Nervous system: instructions are generated from the nervous system by means of electrical impulses towards the muscles of the upper limb so that they carry out the necessary movements to open the door.
2. Muscular system: the muscles of the trunk and the upper limb generate voluntary movement to open the door.
3. Skeletal system: it supports the muscles of the trunk and the upper limb to carry out the door opening movement. It also has joints that help the mechanical movements necessary to open the door.
egg (female) and sperm ( male)
<h2>Urea </h2>
Explanation:
Urea is a small nitrogenous compound which is the main end product of protein catabolism in mammals
- Urea is a nitrogen-containing substance normally cleared from the blood by the kidney into the urine
- It is made predominantly in the liver from ammonia and bicarbonate and is one of the main components of urine
- The rate of synthesis varies from 300 to 600 mmol/day depending on the protein intake
- All of this urea eventually finds its way into the urine
- Because urea makes up a large part of the obligatory solute excretion, its osmotic pressure requires significant volumes of water to carry the urea
- Urea passively crosses biological membranes, but its permeability is low because of its low solubility in the lipid bilayer
- Some cells speed up this process through urea transporters, which move urea by facilitated diffusion
- Urea is passively reabsorbed in the proximal tubule, but its route of transport is not clear
- Urea transporters have not yet been identified for the proximal tubule
