how DNA passes on genetic information?


how DNA passes on genetic information?

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DNA _is_ the genetic information. Every cell has a copy which it uses to make proteins which are the things that make cells work. Therefore, every living cell’s functioning depends on what DNA it has. When cells divide each of the new cells get a copy of DNA from the dividing cell (DNA doubles itself). When human embryos are made, two cells with DNA from mother and father are combined.

DNA is made of molecules that serve as letters and there are little protein machines that read and copy those letters.

DNA stands for deoxyribonucleic acid. That substance IS your genes.

More specifically, DNA tells the cells of your body how to do things like a blueprint. Specifically, how to make other chemical compounds.

Collections of this material form complete “instructions”, if you will, for things like having red hair. “Red hair” is the phenotype (visual expression) of a set of DNA and we call that a gene.

Each of your cells has a long long strand of DNA in it, which stretched out is about 6 feet long (seriously).

That DNA is made up of a long chain of 4 different molecules, which get abbreviated with the letters A,G,C, and T. The order that these molecules are in on the chain stores information on how to make different proteins, which are the molecules your body uses to pretty much “do” everything cells need to do (like moving, burning sugar for energy, making hormones, digesting food, etc). I don’t think it’s useful to get into the specifics of how it stores this information, but I’ll say that proteins themselves are made of long chains of smaller molecules, and that every group of three “letters” stands for a different one of these smaller molecules.

DNA has one other amazing ability–it can replicate itself. When cells divide, it copies itself and you end up with two copies of the same strand of DNA in the two new cells. When our bodies are making sperm or eggs, they are formed in a special way where a randomly selected half of the DNA chain is put in them, which combines with the randomly selected half in the other one when a baby is conceived. This means that babies have 50/50 of their DNA from their mom and dad, but exactly which parts of it come from which parent is random.

DNA is an information medium. You might know that the DNA molecule is shaped like a twisted ladder. The rungs of that ladder are can be made of any of four different chemicals. Those chemicals and more importantly the order they appear in is your genetic code. It’s like letters in a book. Now the DNA molecule is also something like a zipper. The two sides can be unzipped from one another and each is used as a template to build a new strand of DNA. In that way, DNA can be copied to form new cells for growth and reproduction. The next question you might ask is how is that genetic code read to express traits. Your cells contain structures called ribosome that can read RNA ( a molecule like one side of the DNA ladder) and create proteins based on the information they find. Proteins are built like Lego blocks; they can be formed piece by piece by sticking smaller molecules called amino acids together. Each set of three rungs of DNA mean a different amino acid or a special instruction like start building or stop building. So DNA holds information that ribosomes can use to build proteins. How does that determine genetic traits like hair or eye color? The pigments in your hair, eyes, and skin are all proteins. The most common pigment is a brown protein called melanin. Some people have more genes that code for melanin than others and so some people are more darkly colored. Some people have genes that changed or mutated in one of their ancestors and some of their genes no longer code for melanin. They might produce very little pigment and be blond or produce a different pigment like pheomelanine and be red-headed. Now on to the heart of the question. How do parents pass genes to their children, or why do children resemble their parents? Every one of your cells has a full set of DNA organized into structures called chromosomes. Humans have 45 chromosomes in 23 pairs. Why in pairs? Because you get one set from your mother and the other from your father. Usually when your body makes new cells, the entire set of 46 gets copied. However, if your body is making gamete cells, sperm or eggs, those cells only get one half of each pair at random. The two members of each pair can even trade parts so each resulting gamete is highly randomized and completely unique. When an egg cell is fertilized by a sperm cell all the pairs of chromosomes match up and the whole process starts over again