Answer: Positive charge of 1
Explanation: This is because it is believed that it is from the charge of the quarks that make up the nucleons which are protons and neutrons.
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.
Answer:
Recombinant DNA
Explanation:
Recombinant DNA can be used to change the genetic makeup of a cell, as in adding a gene to make a bacterial cell produce insulin.
Answer:
carbon dioxide and oxygen
Explanation:
Carbon dioxide is the waste product of cellular respiration that you breathe out each time you breathe. Blood picks up oxygen and releases carbon dioxide in the lungs. The opposite takes place in the cells where the blood releases oxygen and picks up carbon dioxide.
