The most important idea is that the genetic material of any organism must be able to accurately replicate itself at least every generation (or for multicellular organisms at each cell division).
Base pairing (A-T or U and C-G)allows DNA and RNA (eg in polio virus, see Wikipedia page on RNA dependent RNA polymerase) to create a copy of themselves, when the appropriate enzymes are present. Proteins have no way of making a copy of themselves.
Stability is probably the main reason DNA is the most common genetic material. DNA has no enzymatic activity and was probably selected for to maintain the integrity of the genetic material (rather than having to perform a function for the cell/virus, during which it may be destroyed). The double helix structure also protects its integrity, and proofreading enzymes have also evolved which correct most of the mistakes made at DNA replication. RNA viruses don't have this mechanism- which could be said to be an advantage (as they can rapidly change and therefore avoid their hosts' immune systems), however in non-parasitic organisms most mutations in a gene would lead to a loss of an essential function and the extinction of that genome.
I don't think either of these reasons are relevant, but I think the main reasons retroviruses convert their RNA to DNA are so they can use the host cell's replication machinery (this was they do not need to encode as many genes), and secondly they need avoid the antiviral mechanisms of the cell, which would destroy any double stranded RNA molecules found (even if the virus was single stranded, dsRNA would have to be produced at replication).
Answer:
Life may exist in extreme conditions
Explanation:
The conditions in other planets do not normally resemble those on Earth. They are commonly much hotter or colder and are filled with toxic gases or liquids. It would be easy to think that life could not exist in those inhospitable places, but when we see how life on our own planet has adapted to the harshest enironments we have to think again and consider that life could exist in those extreme planets.
Answer:
B-D-C-A.
Explanation:
The chromosome map helps to understand the location of genes in the genome map. The distance between the genes can be used to locate the genes of chromosome.
The distance between the Band D is 5%. The B and D gene can be located with each other. Then gene C is located after D and the distance between them is 15%. This will give the distance between B and C is 20%. The gene A is located at the last position A and the distance between them 30%.
Thus, the correct answer is B-D-C-A.
Answer:
There is likelihood of inheriting a mutation from your parents would be based on the type of cell in which the mutation was found.
Explanation:
There are two basic types of cell; the germinal cells and the somatic cells. The germinal cells give rise to gamete and these gametes are responsible for the formation of offspring which are produced by the parents. A mutation in any of the gamete that partakes in fertilization will be transferred to the offspring. Mutation that occurs in the gametic cell is called germinal mutation.
The other cell is the somatic cell. The somatic cell are cells in living organism other than the reproductive cell. The somatic cells mutation cannot be transferred to their offspring because most somatic mutations are caused by environmental factors such as radiation and chemicals
A mutant clone might arise if the mutation occurs in a tissue that still has its cell still dividing but if the mutation is in a post-mitotic cell that is, one that is no longer dividing, then the effect on phenotype is likely to be negligible. The result of somatic mutation in a parent can then be transferred to the offspring through the gametic cell
C. Breakdown of fats into glycerol and fatty acids by lipases
