Chapter 6 general information

Genetics

the inheritance and expression of inherited traits

Syndrome

A distinctive association of signs and symptoms occurring together

Phenotype

The physical, biochemical, and physiologic traits of an individual

Genes

The hereditary units transmitted from one generation to another

Chromosomes

The small bodies in the nucleus of a cell that carry the chemical instructions for reproduction of the cell, in addition to other cellular functions

Chromosomes contain DNA, which directs the production of amino acids, polypeptides, and proteins by the cell

DNA has the ability to duplicate itself

Sex Chromosomes

•Chromosomes 1 through 22 are known as the autosomal chromosomes (autosomes)

•23rd set of chromosomes in human cells are the sex chromosomes

X chromosome

Y chromosome

•Barr bodies are only seen in female cells

Mitosis

•The process of cellular division in a somatic cell during a part of the cell’s lifespan called the mitotic cycle

• Prophase

• Metaphase

• Anaphase

• Telophase

• The function of mitosis is to create an exact copy of each chromosome, and, through division of the original cell, distribute an identical set of chromosomes to each daughter cell

Meiosis

The two-step cellular division of the primitive (original) germ cells, which reduces the number of chromosomes by half