Which is one of the six fundamental elements that are found in living organisms?
The researchers will use mice instead of opossums or humans to determine whether the cells of the ear bones originated from the same embryonic cells as the cells that form the jaw in other vertebrates because in this type of experiment, organisms that are ideal are the ones that have a short life span, easy to be researched on and easy to mantain.
It will be very tedious and demanding to use opossums and humans in this type of practical experiment because,it is against the culture and norms guilding human living and existence to use humans as model organisms,opossums as well are very bad model organisms because unlike the mice,opossums are long lived and it will be very difficult to raise and maintain an opossum in a laboratory.
Humans and mice are both mammals just that human is a higher mammal but they share similar features in terms of pattern of development,though there is a clear difference during their early development,so because of the common ancestry shared by the mice and humans,the result of the experiment on the mice with share a close similarity with the pattern that is expected in humans.
The RNA world hypothesis states that the earlier life-forms had relied only on RNA (Ribonucleic Acid) for the purpose of catalyzing the chemical reactions, and storing the genetic information. This hypothesis was proposed by Leslie Orgel, Carl Woese, and Francis Crick.
This hypothesis states that long before the living forms evolved to use DNA as the genetic storage material, the RNA molecules served the purpose of both storing the genetic information and carrying out catalysis, but because of its instability, DNA evolved.
Hence, the answer is RNA world hypothesis.
DNA model given by Watson and Creek in the year of 1953 gave a very detailed study regarding the structure of B DNA which is valid till date and is essentially corroborating with Chargaff's data and Xray diffraction pattern.
<h3><u>Explanation:</u></h3>
The DNA is the most common nucleic acid found in the living organisms as a genetic material. As stated by Watson and Creek, this DNA contains a double helical structure with two sugar phosphate backbones and the nitrogen bases getting projected from it inwards. The backbones are formed of ribose sugar and phosphate and joined together with a phosphodiester bond. The ribose sugar is attached to phosphates at its 3' and 5' Carbon atoms. The nitrogen bases found in DNA are Adenine, Guanine, Thymine and Cytosine. The Adenine has two hydrogen bonds with thymine and guanine has 3 hydrogen bonds with cytosine.
Each full turn of a helix is 34A and each base pair is 3.4A apart. The distance between two strands of DNA is 20A.
Chargaff's rule regarding the equal amount of adenine and thymine as well as guanine and cytosine is matching with this structure. All the other rules also do match with this DNA structure.
I believe it should be lipids
