Traits Question

[student1000]

in bio class we have a new subject. i am having difficulty separating the difference between the following:
autosomal dominant
autosomal recessive
x linked dominant
x linked recessive
y linked
My exams are next tuesday so any help explaining what the differences are and how to recognize them would be greatly appreciated.

[b_d_41501]

Autosomal Dominant
A pattern of Mendelian inheritance whereby an affected individual possesses one copy of a mutant allele and one normal allele. (In contrast, recessive diseases require that the individual have two copies of the mutant allele.) Individuals with autosomal dominant diseases have a 50-50 chance of passing the mutant allele and hence the disorder onto their children. Examples of autosomal dominant diseases include Huntington's disease, neurofibromatosis, and polycystic kidney disease.

Autosomal Recessive
Describes a trait or disorder requiring the presence of two copies of a gene mutation at a particular locus in order to express observable phenotype; specifically refers to genes on one of the 22 pairs of autosomes (non-sex chromosomes)

X-Linked Dominant
Describes a dominant trait or disorder caused by a mutation in a gene on the X chromosome. The phenotype is expressed in heterozygous females as well as in hemizygous males (having only one X chromosome); affected males tend to have a more severe phenotype than affected females.

X-Linked Recessive
A mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males who are hemizygous for the gene mutation (i.e., they have only one X chromosome) and in females who are homozygous for the gene mutation (i.e., they have a copy of the gene mutation on each of their two X chromosomes). Carrier females who have only one copy of the mutation do not usually express the phenotype, although differences in X-chromosome inactivation can lead to varying degrees of clinical expression in carrier females

Y-Linked
A gene on the Y chromosome. A Y-linked gene is by necessity passed from father to son, since the Y chromosome can only be transmitted by a man to his male progeny.

It has often been said that little is known about whether specific genes are or are not Y-linked. This is no longer true. As of the year 2000, a number of genes were known to be Y-linked including:

* ASMTY (which stands for acetylserotonin methyltransferase),
* TSPY (testis-specific protein),
* IL3RAY (interleukin-3 receptor),
* SRY (sex-determining region),
* TDF (testis determining factor),
* ZFY (zinc finger protein), PRKY (protein kinase, Y-linked),
* AMGL (amelogenin),
* CSF2RY (granulocyte-macrophage colony-stimulating factor receptor, alpha subunit on the Y chromosome),
* ANT3Y (adenine nucleotide translocator-3 on the Y),
* AZF2 (azoospermia factor 2),
* BPY2 (basic protein on the Y chromosome),
* AZF1 (azoospermia factor 1),
* DAZ (deleted in azoospermia),
* RBM1 (RNA binding motif protein, Y chromosome, family 1, member A1),
* RBM2 (RNA binding motif protein 2) and
* UTY (ubiquitously transcribed TPR gene on Y chromosome).

[MrMistery]

Don't tell me you knew all those genes by heart because i'll start crying. They don't even ask that kind of thing at IBO

[b_d_41501]

I looked them up so I could copy and paste but I do know them, am I weird for knowing them? lol

[Poison]

Knowing and explaining are different. Explaining (or you can call teaching) something to someone needs more knowledge and proffesionality.

[b_d_41501]

Gotcha bub

[MrMistery]

I know what you mean. I know more bio than some teachers in my school(No, i'm not bragging, they are just stupid ) and yet they can explain them better than me...

[Poison]

That's why we call them 'teacher'.

[MrMistery]

Actually we call them that because they went to university and couldn't get a better job after that

[Poison]

lol. Good one...

[b_d_41501]

Very good one. lol