Biolog 12 - Chapter 12: Chromosomes and Human Inheritance...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 12: Chromosomes and Human Inheritance A. Human Chromosomes Human X (female) and Y(male) chromosomes fall into the “sex chromosome” category (23 rd chromosome in karyotype) The other 22 chromosomes are autosomes which have the same male and female B. Karyotyping The most common technique for diagnosing chromosomal abnormalities (including nondisjunction disorders) The chromosomes are removed and arranged in pairs and photographed. Abnormalities in chromosome number, shape, or size can be detected C. Autosomal Inheritance Patterns Autosomal dominant is a trait that occurs in every generation (i.e. Huntington’s disease) Autosomal recessive homozygous will show trait, but heterozygous will not (i.e. Galactosemia) Certain alleles give rise to genetic disorders and abnormalities D. Sex Determination SRY gene is needed for male sex determination and is a gene present on the Y chromosome and triggers male development XY embryo is male and XX embryo is female (no SRY) E. X- linked Inheritance X-linked recessive genes are usually causes of disorder in males because males only have one X chromosome Examples include Hemophilia, Colorblindness, and Muscular Dystrophy Females that are heterozygous don’t show the recessive trait F. Structural Change Duplication is the gene sequence that is repeated several to hundreds of times and may have adaptive advantages Deletion is the loss of some segment of a chromosome and can cause some serious
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

Biolog 12 - Chapter 12: Chromosomes and Human Inheritance...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online