文档介绍：Chapter 6
ics
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Outline
Chromosomes
Normal Cell Division
Lyon Hypothesis
position of Chromosomes
Genes and Chromosomes
ics
(pg. 198)
The inheritance and expression of inherited traits
Some alterations may be found as part of a syndrome, or may occur independently.
Cleft lip and palate would be an example.
Syndrome
A distinctive association of signs and symptoms occurring together
Some syndromes are inherited and others are not.
ics (cont.)
(pg. 199)
Genotype
The position
Phenotype
The observable appearance
Refers to the physical, biochemical, and physiologic traits of an individual
Chromosomes
(pg. 199)
Genes
The hereditary units transmitted from one generation to another
Genes are found on chromosomes, which are located in the nucleus of a cell.
Chromosomes contain DNA, which directs the production of amino acids, polypeptides, and proteins by the cell.
DNA has the ability to duplicate itself.
Chromosomes (cont.)
Normal Cell Division
Mitosis
Stages of mitosis
Meiosis
Mitosis
(pg. 199)
Somatic cells
All cells of the body, with exception of ova and spermatozoa
Mitosis
The process of cellular division in a somatic cell during a part of the cell’s life span called the mitotic cycle.
Mitotic Cycle
(pgs. 199-200)
After each cell division plete, the cell enters the gap 1 (G1) phase.
This is followed by the S phase, where replication of DNA takes place.
The gap 2 (G2) phase follows the S phase and ends when mitotic division takes place.
Stages of Mitosis
(pgs. 199-200)
Four stages
Prophase
The chromosomes are lining up toward metaphase.
Metaphase
Chromosomes at the equatorial plane of the cell
Long and short arms are joined at the centromere.
Each identical half is called a chromatid.
Anaphase
The chromatids are in the process of splitting.
Telophase
Cytokinesis occurs.