The Human Genome Chapter 14 The Human Genome

The Human Genome Chapter 14

The Human Genome In humans, diploid (2 n) = 46 That 44 means somatic cells have 46 chromosomes autosomal chromosomes and a pair of sex chromosomes

Pedigrees A pedigree is a diagram that traces a single trait through several generations

Individuals shaded in have attached earlobes. Is this trait dominant or recessive? RECESSIVE!! Partially shade carriers and label genotypes

Solution:

A Pedigree for a sex-linked recessive trait: Shade in known carriers and label genotypes.

Solution:

The Human Genome Chapter 14 Blood Typing and Chromosomal Genetic Disorders

Use only to type blood in lab (serum reacts to antigens present) Blood Typing Chart Blood Type A B AB O Rh+ Rh Genotypes Antigens Antibodies Donate to Receive from Reaction to Anti-A Reaction to Anti-B Reaction to Anti-Rh

Use only to type blood in lab (serum reacts to antigens present) Blood Typing Chart Blood Type Genotypes A IAIA, IAi B IBIB, IBi AB IAIB O ii ++, +Rh+ dominant -Rhrecessive Antigens Antibodies Donate to Receive from Reaction to Anti-A Reaction to Anti-B Reaction to Anti-Rh

Use only to type blood in lab (serum reacts to antigens present) Blood Typing Chart Blood Type Genotypes A IAIA, IAi B IBIB, IBi AB IAIB O ii ++, +Rh+ dominant -Rhrecessive Antigens Antibodies A Anti-B B Anti-A AB none Anti-A Anti-B Rh none *only if exposed to antigen Donate to Receive from Reaction to Anti-A Reaction to Anti-B Reaction to Anti-Rh *Rh- mothers can be exposed to the Rh antigen if the fetus is Rh+

Use only to type blood in lab (serum reacts to antigens present) Blood Typing Chart Blood Type Genotypes A IAIA, IAi B IBIB, IBi AB IAIB O ii ++, +Rh+ dominant -Rhrecessive Antigens Antibodies Donate to Receive from A Anti-B A, AB A, O B Anti-A B, AB B, O AB none AB, A, B, O none Anti-A Anti-B A, B, AB, O O Rh none pos or neg none *only if exposed to antigen pos or neg only Reaction to Anti-A Reaction to Anti-B Reaction to Anti-Rh *Rh- mothers can be exposed to the Rh antigen if the fetus is Rh+

Use only to type blood in lab (serum reacts to antigens present) Blood Typing Chart Blood Type Genotypes A IAIA, IAi B IBIB, IBi AB IAIB O ii ++, +Rh+ dominant -Rhrecessive Antigens Antibodies Donate to Receive from Reaction to Anti-A Reaction to Anti-B Reaction to Anti-Rh A Anti-B A, AB A, O clumps - B Anti-A B, AB B, O - clumps AB none AB, A, B, O clumps none Anti-A Anti-B A, B, AB, O O - - Rh none pos or neg clumps none *only if exposed to antigen pos or neg only - *Rh- mothers can be exposed to the Rh antigen if the fetus is Rh+

Nondisjunction Occurs when a chromosome or chromosomes fail to separate in meiosis Individuals end up with the wrong number of chromosomes ( < or > 46 total) Risk factor increases with age

Nondisjunction of Autosome Down Syndrome caused by trisomy 21 (3 copies of chromosome #21)

Nondisjunction of Sex Chromosomes Turner Syndrome (karyotype 45, XO): Female; sterile; sex organs do not develop at puberty Klinefelter’s Syndrome (Karyotype 47, XXY): Male; infertility; fewer secondary sex characteristics; variations are 48, XXXY and 49, XXXXY