What are chromosomes and genes?
Chromosomes are the physical structures that contain the DNA and genes necessary for development. Chromosomes are located in the center of the cell, in the area called the nucleus. A normal human cell should contain exactly 46 chromosomes. There are 23 pairs of chromosomes. The first 22 pairs are identified by number and organized by size. The 23rd chromosome pair is referred to as the sex chromosomes which determine gender. Females normally have 2 of the same sex chromosomes, called the X chromosome, while men normally have 2 different sex chromosomes, known as the X and Y chromosomes. A normal set of chromosomes is 46,XX for a female and 46,XY for a male. In a normal conception, both the egg and sperm cells should contribute exactly 23 individual chromosomes, one of each of the 22 numbered pairs and one of the sex chromosome pair. When an egg with 23 chromosomes fuses with a sperm with 23 chromosomes, the correct chromosome number of 46 (23 pairs) is again present, and the fertilized
Chromosomes are the tiny inherited structures in our cells that carry our genes. We have 46 chromosomes in each cell of our bodies. They are found in pairs, and we get one of each pair from our mothers and one of each pair from our fathers. Therefore, we inherit 23 chromosomes from our mothers’ eggs and 23 from our fathers’ sperm. Some people can have extra or missing chromosomes, which cause them to have mental and physical disabilities. Genes are the instructions that tell our bodies how to grow and develop properly. Genes are made of DNA. DNA is like a code that our cells can understand and translate to make all the substances that our bodies need. Genes are located on our chromosomes. Since we have two copies of each chromosome, one from mom and one from dad, we also have two copies of each gene. Sometimes genes can be damaged so they do not work properly. This can result in a person having mental retardation, birth defects, or genetic illness.
By Manuel Luciano da Silva, Medical Doctor July 26 205 I want this series of articles dealing with the study of DNA concerning the possibility of the Portuguese nationality of the navigator Cristvo Colon or Christopher Columbus, to be understood even by those persons that did not have the opportunity to acquire advanced or medical education. This is the reason why I consider it necessary that my readers understand very well what are chromosomes and genes so they will be able to comprehend the specific study of Y chromosome and also of mitochondria. (composed of two Greek words Mito = thread like + chondrion = rod-shaped components). Chromosome Chromosome is a name composed by two Greek words: chromo = color , plus soma = body. For us to better understand the meaning of chromosome we have to analyze the composition of a cell. The best example of a cell is a chicken egg which has three parts: (1) the shell or membrane; (2) the white of the egg or cytoplasm; and (3) the yolk or the yellow
Related Questions
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