That which exists, a being, a creature, an entity.
Because each gamete has only half the amount of DNA of a normal cell, when the male and female gamete unite, the zygote has a complete set of DNA.
Into the human digestive system, mucus is used as a lubricant for materials that must passover membranes e.g, food passing down the esophagus. A layer of mucus around the inner walls of stomach is vital to protect the cell things of that organ from the highly acidic environment with in it.
All organisms need food for the energy required to live and grow. They all excrete (get rid of) waste products, and detect changes in their surroundings and respond to them. All living organisms follow a LIFE CYCLE of growth and development, reproduction, and death.
The correct answer is Island Arc. A string of islands known as an Island arc can form from the collision of two oceanic plates. Island arcs are curved chains of the volcanic islands, usually located in the deep ocean trenches on the convex side.