Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes...

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Sex Linked Genes The Xs and Ys of Genetics

Transcript of Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes...

Page 1: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Sex Linked Genes The Xs and Ys of Genetics

Page 2: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Sex Linked Genes There are 23 pairs

of chromosomes and one of those pairs are the sex chromosomes.

There are either X chromosomes or Y chromosomes.

Page 3: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Sex Linked Genes These

chromosomes not only carry the genes that determines male and female traits, but also those for some other characteristics as well.

Genes that are carried by either sex chromosome (X or Y) are said to be SEX LINKED

Page 4: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Males Men normally have

an X and a Y combination of sex chromosomes.

Since only men inherit the Y chromosome, they are the only ones that inherit Y-linked traits.

Page 5: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 6: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Females

Women have 2 X chromosomes

Page 7: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 8: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 9: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

X Linked Traits Men and

Women can get the X-linked traits since both inherit X chromosomes.

Page 10: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 11: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Sex inheritance patterns for male and female children

Page 12: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

X Chromosome Traits

Men only have one X chromosome

Therefore genes on that chromosome are expressed in the male phenotype, even if it is a recessive gene.

Page 13: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

X-linked traits In women, a

recessive allele on one x chromosome is often masked on their phenotype

May have a dominant normal allele on the other carriers of X-linked traits but more rarely have them expressed in their own phenotypes

Page 14: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 15: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

X-linked traits In humans, at least

120 genes are know to be X-linked.

Genes for hemophilia, red-green color blindness, congenital night blindness, and Duchene muscular dystrophy

Page 16: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Hemophilia An X-linked

genetically inherited recessive disease

Can not clot their blood

Severe bleeding from minor cuts

Mostly in males

Page 17: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 18: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Red-Green Color Blindness X-linked Cannot perceive red and green in the same Most often afflicts males

Page 19: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 20: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 21: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Muscular Dystrophy (MD) Characterized by a gradual irreversible

wasting away of skeletal muscle. An X-linked trait most often passed on to

sons from their mothers. Begins to weaken the legs of boys by age

3 and gets worse every year. No cure and inflicted usually die by age

30.

Page 22: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,
Page 23: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Y-linked Traits The Y chromosome is small and therefore

does not contain many genes Y linked diseases are very rare Only passed from father to son. Example: Male infertility

Page 24: Sex Linked Genes - Mrs. Connor's Website St. James Collegiate · 2018-09-10 · Sex Linked Genes These chromosomes not only carry the genes that determines male and female traits,

Hypertrichosis Pinnae. Hairy ears Can happen later in

life. Y-linked