DNA, Cell and Chromosome
The chemical DNA was first discovered in 1869, but its role in genetic inheritance was not demonstrated until 1943. In 1953 James Watson and Francis Crick determined that the structure of DNA is a double-helix polymer, a spiral consisting of two DNA strands wound around each other. The full form of DNA is deoxyribonucleic acid. DNA is the material that in human almost all other organisms. Almost Of the DNA is located in the cell nucleus but the small amount of DNA can also be found in mitochondria.DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The order of these bases is what determines DNA’s instructions, or genetic code..
Within the nucleus the DNA strand are tightly packed to from chromosomes. During the cell division the chromosome are visible. There is 23 pair (46 chromosomes) in your body.Each chromosome has a constrictions point called the centromere from where two are are formed. The short arm of the labelled the “p arm”. Tube long arm of the chromosome is lableled the “q arm”.
There are 22 autosome in you body and there is 1 gender chromosome that is x and y.
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. Cells also contain the body’s hereditary material and can make copies of themselves.
Cells have many parts, each with a different function. Some of these parts, called organelles, are specialized structures that perform certain tasks within the cell. Human cells contain the following major parts :Endoplasmic reticulum (ER), Cytoplasm, Plasma membrane, Ribosomes, Lysosomes and peroxisomes,
Cytoskeleton, and Golgi apparatus.