DNA is the type of organic compound that stores the genetic information in a living organism. DNA is made up of two strands of nucleotides, which include a phosphate group, five carbon sugar, and a nitrogenous base. Each individual strand in held together by strong covalent bonds (a bond formed as a result of the distribution of electrons between atoms). The two strands are then joined to each other by hydrogen bonds between complementary bases. There are four nitrogenous bases: adenine, thymine, cytosine, and guanine. Adenine is complementary to thymine while guanine is complementary to cytosine.
Role of Hydrogen bonds
Hydrogen bonds are produced when a negatively charged atom such as oxygen and a hydrogen atom unite. The hydrogen bonds between the nitrogenous bases in DNA play …show more content…
These mechanisms are genetic drift, natural selection, mutations, gene flow, and non-random mating. Mutations involve a permanent change in the DNA sequence of an organism. Mutations can be beneficial, neutral, detrimental, or fatal to organisms. Mutations are passed on from parent to offspring and can cause evolution by increasing the size of the gene pool. Another mechanism of evolution is gene flow. Gene flow takes place when organisms immigrate or emigrate from a population permanently. This can can either increase or decrease in the gene pool as a whole. A third mechanism of evolution is genetic drift in which a random event acts on a small population and decrease the size of the gene pool. The fourth mechanism of evolution is non-random mating. In non-random mating, mates are chosen based on preferential trait or physical appearance. Those preferential traits can then be passed on to the offspring. Natural selection is the fifth major mechanism of evolution. Natural selection works on the organism, allowing for adaptations that give them increased survival and reproductive