Can anybody explain me in simple words - about Chromosome, DNA and Genes.?

Question

What do they do do when they say 'DNA matching'?Can the cell from any part of the body compared with the cell from any other part of the same body?( I mean - cell from nail can be compared with the cell from blood) Will they be identical?

Answer 1

Ok.. young grasshopper - lets start with DNA.

DNA from your hair, the inside of your mouth, finger nails, even pubes are all alike!

As you probably know, DNA = Deoxyribonucleic Acids, and it is double stranded which forms a double helix. Thus DNA acts as an acid and gives up protons (remember this). There are 4 "letters" that represent macromolecules - A T G & C for DNA, and A U G & C for RNA. RNA is composed simlarly as DNA, however it is single stranded and is short an Oxygen, hence DE-oxy :). A will always match to T, and G to C (in DNA). In RNA U will simply replace T (thus U matching to A). This occurs because these macromolecules carry a certain shape, and thus will only fit to its counter. Anyhoot, DNA Matching is most likely going to be Agarose Gel Electrophoresis - a technique used to identify if two different strands of DNA are alike.

First you have to extract the DNA (commonly done through ultra-centrifuges). Then you have to put it in a solution and prepare an agarose gel. Concentrations, temperatures and voltages are all extremely important - as the DNA strands are relatively fragile, and can be denatured! You put the DNA solution and mix it with some cutting enzymes, such as Eco R1, Eco R2, etc...

The way this works is there are enzymes that have been identified and known to cut DNA at specific sites, where a specific order of base pairs go. This enzyme cuts it at that site and keeps moving up the strand till it gets to the next one, and continues until it gets to the end of the strand. After doing so there will be many strands, of variang base-pair lengths. Some strands may have 500bp (basepairs), 500000bp, 10000000bp, and so on, but as it goes through the electrophoresis technique, these segments will seperate within the gel, and through observation, you can line up these seperated segments with DNA from a suspect, and if they match perfectly, you have the person.

You can read more about this DNA matching by searching on google for "Agarose Gel Electrophoresis." It is a simple process, although it may seem very complicated at first. If its for a class, i suggest you learn every detail.

Answer 2

Though the cells as such in different parts of the body will be different, yet the genetic material inside all of them remains the same. The difference stems from the fact that different genes are switched on or switched off in different tissues leading to the variety that we see. For eg. only the pancreatic beta cells produce insulin and only the cells of the thyroid produce thyroxine.

DNA matching however is something different. It is done to compare the DNA of two individuals, or two species etc. It might be used in legal cases regarding paternity and is also used by evolutionary biologists to study the pattern of evolution between similar or different species.

DNA is the basic building block which encodes our genetic material. Stretches of DNA when in a certain format constitute a gene which produces a protein. Chromosome is at the highest level...it hold thousand of genes and is the basic form of heredity. So of the 46 chromosomes in each of your cells, 23 are from your father while another 23 come from your mother.

Answer 3

Let's start with the first part:

DNA is the building block of life. It consists of 4 nuclotides in different patterns to create two strands that wrap around each other in a helix. If we take a step backwards, we can see that large amounts of DNA can encode proteins, starting with a process known as translation. These translated DNA sequences are known as genes (now some untranslated bits of these DNA sequences are also part of the genes, but that's adding some complexity). IF we take another step back, we see that many genes are on a single strand of DNA. This strand of DNA is very large, and wrapped around itself and a group of proteins called histones. Packed together in this fashion, they are called chromosomes (simply put, a long piece of DNA that contains a bunch of genes).

DNA matching is a process where they compare samples of DNA to each other. We can extract DNA from any cell in your body and compare it to the same or other tissue (saliva to skin to sperm to hair). When it is identical, we know they came from the same person (or, at least, reasonably sure). DNA will be the same no matter where it comes from in your body.

We can also compare DNA between people, and that is what is done during paternity testing. The child will have a mixture of DNA from the mother and the father - if a pattern shows up that is not part of their individual genes, then one of them is not the parent.

Answer 4

DNA is the double-helical polymer of de-oxy ribonucleic acids. DNA is basically made up of polymers called nucleotides that in turn are composed of a ribose sugar, phosphate group and a nitrogen base. The entire DNA in one cell is nearly 5 feet long when fully extended.
However, u know that the DNA has to fit into a micro-sized nucleus. So, all the 5 ft of DNA is coiled, super-coiled to form a compact structure in association with histone proteins, called chromatin.
The chromatin in Metaphase is condensed to form short, thick, dense structures called Chromosomes. So, basically, DNA arranged in a coiled, condensed state is called Chromosome.
DNA is a sequence of nitrogen bases, which are trascribed to m-RNA and then m-RNA is translated into proteins. Not all DNA can be transcribed and translated this way. Only those sequences of bases that make sense in the protein language, that is, form proteins, are transcribed. These sequences are called GENES. So, genes are specific sequences of nucleotides on DNA/Chromosomes.
Then, cells in all parts of the body are essentially the same in terms of chromosomal content. They all have the same Chromosomes. However, the cells differ morphologically based on their function. They also differ in the kind of proteins they produce or recognize. This is because not all cells produce all proteins though they have the genes encoding those proteins. Based on their location, and function, the cells have some genes turned on or off.
DNA matching is comparing the sequences of DNA of two persons or two DNA samples to see if they have any relationship.

Answer 5

Chromosomes: The chromosomes are the carriers of genes.
Genes: These are the genetical characters present in DNA.
DNA: It carries the genetic information, is the most important constituent of the chromosome.

The cells of nails and that of the blood cannot be compared because the nail cells are dead cells and the blood cells are living cells.

Answer 6

CHROMOSOME [chromosome] , structural carrier of hereditary characteristics, found in the nucleus of every cell and so named for its readiness to absorb dyes.

GENE [gene] the structural unit of inheritance in living organisms. A gene is, in essence, a segment of DNA that has a particular purpose, i.e., that codes for (contains the chemical information necessary for the creation of) a specific enzyme or other protein. The strands of DNA on which the genes occur are organized into chromosomes .

DNA [nucleic acid] any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis.

Answer 7

Yes, all the cells have the same DNA. Different genes get turned on and off in different tissues.

Answer 8

NAH...I don't think so.....very complicated stuff