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.
Dna damage can occur as a result of exposure to chemicals or ultraviolet radiation. This is what happens during nucleotide excision repair of damaged dna. A multienzyme complex crosses the DNA in search of distortions in the double helix, once located, the phosphate skeleton of the affected chain is cut on both sides of the altered region, a helicase eliminates the oligonucleotide resulting from digestion, the "Gap" "is filled with a DNA polymerase and a ligase.
Because by damaging capsids, there is no place for the bad DNA to be stored. So the drug destroys the DNA so no more of the virus can be stored in the body.
<span> One reason farmers often choose GM crops over non-GM crops is because GM crops are able to produce more yield. When farmers use GM crops, there are many benefits that they could gain. It has been proven that GM crops are more resistant to pests, and other harmful substances, which also reduce the costs for pesticides and crop-maintenance. Since GM crops are more resistant to harmful substances, more of them can be used by farmers.</span>
