Every living organism is made of cells. Every cell has a nucleus, and every nucleus has chromosomes. Human beings have 46 chromosomes or 23 chromosome pairs and each chromosome contains hundreds of genes. These genes contain the recipes, for proteins that make most of the body. Structural proteins form things such as skin, hair, and muscle. These chromosomes are very long compact coils of DNA (Deoxyribonucleic Acid) that store all the information that the body inbeds such as how one looks and functions. This paper will first describe the structure of DNA; second discuss how the structure of DNA allows it to serve as the basis for inheritance, third examine how meiosis allows DNA to be divided into gametes and finally, describe how this relates to Gregor Mendel’s patterns of inheritance. The structure of DNA
DNA is a thread formed by two strands, related together to form a Double Helix. The Double Helix looks like a twisted ladder. The "sides" of this "ladder" are long units called nucleotides and are made of three parts; a nitrogenous base, a sugar, and a phosphate group. The sides of the ladder or the nucleotides from the two separate strands of the DNA are attached by an appendage made of one of four separate bases. These appendages represent the "rungs" of the DNA "ladder" and are attached to the complimentary strand or side of the DNA. The bases or “rungs” are made of either Adenine (A) and Thymine (T) or Cytosine (C) and Guanine (G). The attachment of the strands by the bases is specific as Adenine can only join with Thymine, and Cytosine can only join with Guanine. Since this base pairing is specific, if one knows the sequence of bases along one strand of the DNA one will also know the sequence along the complimentary strand. DNA as a Basis for Inheritance
The unique pairing of the rungs of the DNA ladder is the basis for DNA acting as the molecule of inheritance. DNA duplicates in a process called DNA replication. This process involves the separation of...
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