A molecule is a carbohydrate if it contains carbon and water
A) DNA fulfils all three conditions:
<span>(1) copy itself precisely - in the process of replication, DNA copies itself and two molecules of DNA are formed. This process is very precise thanks to the great number of proteins involved in these process that prevents error occurring and proteins that can fix the error if it occurs.
(2) be stable but able to be changed - DNA is very stable molecule otherwise, it cannot be a genetic material. However, its chains can separate in a short length so the translational machinery can attach to it and the process of transcription can occur. Also, in crossing over, during meiosis, </span>the exchange of genetic material occurs and chromosomes change a bit.<span>
(3) be complex enough to determine the organism’s phenotype - it contains a number of genes responsible for different traits. All of this results in the </span>organism’s phenotype.
B) DNA copies itself. <span>Meselson and Stahl conducted the experiments on DNA replication in which they used </span>E. coli<span> bacteria as a model system. After they labelled all bacteria's DNA with heavy 15N by using medium with heavy 15N, they switched bacteria to medium with light 14N. After several generations, all bacteria's DNA was labelled with light 14N. This experiment evidenced that the self-replication of DNA is semi-conservative process.</span>
Answer:
<h2>Liver, testosterone </h2>
Explanation:
The cholesterol is an important type of organic molecule that has many important roles in organisms. It is a sterol that is also called a modified steroid. It plays an important role in the cell membrane of the organism. Generally, it is synthesized in the liver and some other parts of the body. The synthesis of cholesterol is regulated by a homeostatic mechanism. Testosterone is synthesized from the cholesterol so cholesterol acts as starting material. Testosterone plays an important role in the development of the reproductive tissues of the male.
