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Types of Chromosomes
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Karyotypes of large mammalian organisms, such as humans, show two major types of chromosomes; autosomes and sex chromosomes.
Key concepts:
- Human somatic cells have a total of 46 separate, individual chromosomes.
- Of these chromosomes, 44 of them form 22 pairs of homologues of different sizes, structures and banding patterns.
- These 22 pairs of chromosomes carry most of the genes which code for the human body; they are called autosomal chromosomes, or autosomes.
- Two chromosomes are different. Usually termed "X" and "Y", these are the chromosomes that are involved in determining the phenotype of sexual identity; maleness or femaleness.
- Under standard circumstances an individual that is XY is phenotypically male, while an individual that is XX is phenotypically female.
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Science@a Distance
© 2001, Professor John Blamire |
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