Sex Linked Inheritance Wait What Whats a mosaic
- Slides: 37
Sex Linked Inheritance
Wait…. What? ? ? • What’s a “mosaic”? • Remember the FLUID MOSAIC MODEL? ? – The Plasma Membrane – P. S. What is a Plasma Membrane? • An individual (organism, artwork, organelle) made up of smaller, different ”pieces”… • So, in a way, WE ARE MOSAICS, too!
Calico Cats • Calico Cats can ONLY BE Female!
Why? ? • Because a cat’s fur color is linked to two different alleles on the “X” chromosome • And…For a cat to have more than two colors… • It must have TWO X CHROMOSOMES!
Sex-Linked Inheritance • Sex-Linked Inheritance means that a gene (or multiple genes) are carried on one of the sex chromosomes
Sex-Linked Inheritance • Remember, Females have XX and Males are XY. – The Y has very few genes - mainly those that contribute to male characteristics. (Only about 87 genes total. ) – The X much more genetic information – for gender and other characteristics. (About 2050 genes!)
Sex-Linked Inheritance • Some genes for a disorder/disease are located on one of the sex chromosomes • If the gene is linked to the “Y” chromosome, women will not have the disorder. – Why? _________________ • If the gene is linked to the “X” chromosome, and it is recessive, women will not express the disorder. – Why? ___________________ • If the gene on “X” is dominant… both will express it!
Who is usually affected by Sex-Linked Disorders? • MEN! Genes for certain traits are on the X chromosome only… – Since Men only have one X chromosome then they are more likely to have the disorder – Women are somewhat protected since they have two X chromosomes and are less likely to inherit receive disorders. • If women receive a recessive gene on one X chromosome, they are called “carriers” because they “carry” the gene but don’t express the disorder
Sex-Linked Disorders • Affected males never pass the disease to their sons – Men give their “Y” to their sons! • Affected males pass the defective X chromosome to all of their daughters, who are described as carriers – This means they carry the disease-causing allele but generally show no symptoms • Female carriers pass the defective X chromosome to… – half their sons (affected by the disease) – half their daughters (who are carriers) – The other children inherit the normal copy of the chromosome
How do you solve Sex-linked Problems? If Red eyes are dominant and sex-linked, show the cross between a homozygous red eyed female and a white eyed male. • You determine which trait (or disorder) is dominant or recessive • Set up a punnett square using XX for females and XY for males. – Assign alleles for X only! Genotypes: XRXr , XRY Phenotypes: All offspring have red eyes. • Solve as usual, keeping in mind that the Y chromosome has no allele!
Your Turn! • Hemophilia is a sex-linked trait where XH gives normal blood clotting and is dominant to the hemophilia allele Xh • Identify the genotypes of… 1) a woman with normal blood clotting whose father had hemophilia 2) a normal man whose father had hemophilia. • What is the probability that a mating between these two individuals will produce a child, regardless of sex, that has hemophilia?
Set up the Punnett Square! - a woman with normal blood clotting whose father had hemophilia XHXh - a normal man whose father had hemophilia X HY Genotypes: Phenotypes:
What are some X-linked disorders? • • ALD Hypertrichosis Duchenne muscular dystrophy Hunter Syndrome Menkes disease(kinky hair syndrome) Hemophilia Color blindness Inherited diabetes (Type 1)
ALD (Adrenoleukodystrophy) • A deadly genetic disease that is a result of fatty acid buildup caused by the enzymes not functioning properly • Causes damage to the nerves, resulting in neurological issues and, later, death
Hypertrichosis • An abnormal amount of hair growth over the body – Informally called werewolf syndrome, because the appearance is similar to the mythical werewolf
Hypertrichosis
Are you colorblind?
Color Blindness • Having a decreased ability to see some colors or differences in colors • Red-Green is most common
Think how difficult some things would be if you have colorblindness
What about this…. Imagine life without being able to see true colors!
Menke’s Disease (Kinky Hair Syndrome) • Rapid deterioration of the nervous system. • Weak muscle tone, sagging facial features, seizures, developmental delay, and intellectual disability caused by enzymes not functioning • Children with Menkes syndrome typically begin to develop symptoms during infancy and often do not live past age 6
Menke’s Disease
Hemophilia • The “Royal Blood Disease” impairs the body's ability to make blood clots – Clots are needed to stop bleeding • This results in people bleeding longer after an injury and an increased risk of bleeding inside joints or the brain
Hemophilia • Remember the Royal Family?
Tay-Sachs • Tay-Sachs disease is a rare inherited disorder that progressively destroys nerve cells (neurons) in the brain and spine • Enzymes are the culprit AGAIN! • Paralysis of the nerves cause eventual death
Tay-Sachs Tay Sachs
Duchene Muscular Dystrophy • Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness • Until relatively recently, boys with DMD usually did not survive much beyond their teen years – Advances in cardiac and respiratory care means that survival into the early 30 s is becoming more common
Duchenne Muscular Dystrophy
PKU (Phenyl. Keton. Urea) • Decreased metabolism of the amino acid phenylalanine – Enzymes can’t break it down! • Untreated PKU can lead to intellectual disability, seizures and death
PKU
Cystic Fibrosis (CF) • A genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine Cystic Fibrosis • The enzymes required to break down mucous are not functioning, so the mucous collects and clogs…
SCID (Severe combined immunodeficiency) • Do you know “David, the Boy in the Bubble”, who was born without a working immune system?
SCID • What happens when your immune system doesn’t work? ? ? https: //www. nytimes. com/video/u – s/100000004077071/the-boy-inthe-bubble. html
Albinism • Albinism is an inherited genetic condition that reduces the amount of melanin pigment formed in the skin, hair and/or eyes. Albinism occurs in all racial and ethnic groups throughout the world. – As well as other species!
Albino Animals
Different degrees of Albinism…
Y linked • Hairy ears
- Sex linked punnet square
- Sex sex sex
- Sex in the greenhouse
- Sex sex sex
- Sex sex sex
- Sex sex sex
- Whats sex linked
- Whats a sex linked trait
- Sex can wait
- Sex can wait thin your paint
- Pedigree symbols
- Y linked inheritance
- Sex linked punnett squares
- X linked inheritance
- Sex cat
- Advantage of linked list
- Difference between an array and a linked list
- Perbedaan single linked list dan double linked list
- Sex linked pedigree
- What are sexlinked traits
- What are sexlinked traits
- X linked traits
- Linked genes punnett square
- Hemophilia punnett square worksheet
- Pedigree dominant or recessive
- Autosomal vs sex linked
- Autosomal vs sex linked
- Flurorescein
- Sex linked disorders
- In fruit flies white eyes is a sex linked recessive trait
- X linked recessive punnett square
- Color blindness is a sex-linked, trait.
- Is baldness a sex linked trait
- Is blood type sex linked
- Sex determination in drosophilla
- Sex determination and sex linkage
- Once a sex offender always a sex offender
- Vertical mosaic