1) B
(I'm not so sure of this one) All of the other options have a steady impact on population regardless of the density of organisms except competition
2) D
Increased carbon dioxide levels would not hinder plant growth, and tsunamis aren't really linked to carbon dioxide levels. Increased carbon dioxide is unlikely to lower the air temperature so only D is left.
3) A
4) Three properties of water that allow it to sustain life are that it is adhesive, it is a good solvent, and cohesion. Adhesion is important in situations such as water travelling up xylem tubes in plants so that the water is not pulled down by gravity and can reach parts of the plant that need water. Cohesion allows the water being pulled up the xylem to stay together and for water molecules to be pulled when a neighbouring one is moved. Water being a good solvent allows inorganic minerals to be taken with water through vascular tissue, such as in the previous example.
The object has to possess movement, growth and development, response to stimuli, reproduction, use of energy and possession of cellular structures.
HOPE THIS HELPS!
Hemostasis is the process by which bleeding is stopped, that is, a process by which the blood is kept back in the broken blood vessel. It is the first stage in the wound healing process.
During hemostasis, three rapid steps occur simultaneously. In the first step, the blood vessel constrict in order to reduce the quantity of blood that is flowing out, secondly, platelets stick together in order to form a temporary seal which covers the break and thirdly blood clottings formed by adding fibrin threads which serves as molecular glue on the surface of the wound.