which part of our DNA makes the way how we looks like?

Question

because of the DNA their is a very big chance that childeren wil looks like their parents, but sometimes it is possible that people who does not belong to the same blood line looks like each other

Answer 1

All of it.

There are no genes for facial looks. The heredity of a person does have a lot to do with how they look, but environmental conditions (including diet and stress) can have a lot to do with how the body is organized.

Even with all of the gene mapping that has been done with humans, there are currently no exact "genes" known which could give someone a nose like Michelle Pfeiffer or eyes and eyebrows exactly like Johnny Depp. In many case, redundant genes and multiple gene expressions are just now being learned about and studied seriously.

In some cases you might say that most humans do look something alike, but even identical twins can often (with identical DNA) be distinguished from each other.

Answer 2

Chromosomes and inherited traits
Max Delbrück, Nikolai V. Timofeeff-Ressovsky, and Karl G. Zimmer published results in 1935 suggesting that chromosomes are very large molecules the structure of which can be changed by treatment with X-rays, and that by so changing their structure it was possible to change the heritable characteristics governed by those chromosomes. In 1937 William Astbury produced the first X-ray diffraction patterns from DNA. He was not able to propose the correct structure but the patterns showed that DNA had a regular structure and therefore it might be possible to deduce what this structure was.

In 1943, Oswald Theodore Avery and a team of scientists discovered that traits proper to the "smooth" form of the Pneumococcus could be transferred to the "rough" form of the same bacteria merely by making the killed "smooth" (S) form available to the live "rough" (R) form. Quite unexpectedly, the living R Pneumococcus bacteria were transformed into a new strain of the S form, and the transferred S characteristics turned out to be heritable. Avery called the medium of transfer of traits the transforming principle; he identified DNA as the transforming principle, and not protein as previously thought. He essentially redid Frederick Griffith's experiment. In 1953, Alfred Hershey and Martha Chase did an experiment (Hershey-Chase experiment) that showed, in T2 phage, that DNA is the genetic material (Hershey shared the Nobel prize with Luria).


Francis Crick's first sketch of the deoxyribonucleic acid double-helix patternIn 1944, the renowned physicist, Erwin Schrödinger, published a brief book entitled What is Life?, where he maintained that chromosomes contained what he called the "hereditary code-script" of life. He added: "But the term code-script is, of course, too narrow. The chromosome structures are at the same time instrumental in bringing about the development they foreshadow. They are law-code and executive power -- or, to use another simile, they are architect's plan and builder's craft -- in one." He conceived of these dual functional elements as being woven into the molecular structure of chromosomes. By understanding the exact molecular structure of the chromosomes one could hope to understand both the "architect's plan" and also how that plan was carried out through the "builder's craft." Three groups took up Schrödinger's challenge to work out the structure of the chromosomes and the question of how the segments of the chromosomes that were conceived to relate to specific traits could possibly do their jobs.

Just how the presence of specific features in the molecular structure of chromosomes could produce traits and behaviors in living organisms was unimaginable at the time. Because chemical dissection of DNA samples always yielded the same four nucleotides, the chemical composition of DNA appeared simple, perhaps even uniform. Organisms, on the other hand, are fantastically complex individually and widely diverse collectively. Geneticists did not speak of genes as conveyors of "information" in such words, but if they had, they would not have hesitated to quantify the amount of information that genes need to convey as vast. The idea that information might reside in a chemical in the same way that it exists in text--as a finite alphabet of letters arranged in a sequence of unlimited length--had not yet been conceived. It would emerge upon the discovery of DNA's structure, but few researchers imagined that DNA's structure had much to say about genetics.

DNA is responsible for the genetic propagation of most inherited traits. In humans, these traits range from hair color to disease susceptibility. The genetic information encoded by an organism's DNA is called its genome. During cell division, DNA is replicated, and during reproduction is transmitted to offspring. The offspring's genome is a combination of the genomes of its parents. Lineage studies can be done because mitochondrial DNA only comes from the mother, and the Y chromosome only comes from the father.

In humans, the mother's mitochondrial DNA together with 23 chromosomes from each parent combine to form the genome of a zygote, the fertilized egg. As a result, with certain exceptions such as red blood cells, most human cells contain 23 pairs of chromosomes, together with mitochondrial DNA inherited from the mother.