Lesson 3: Extensions of Mendelian Inheritance Flashcards
inheritance of a trait that is determined by a gene located on one of the sex chromosomes (X and Y)
sex-linked inheritance
traits controlled by genes present on X chromosomes
X linked inheritance
Present in both males and females
X linked inheritance
May be in dominant or recessive
X linked inheritance
daughters of an affected father but none of his sons are affected
X linked inheritance
__ are expressed in males and homozygous female
Recessive X linked traits
No dominant and recessive
Y linked inheritance
traits controlled by genes present on Y chromosome
Y linked inheritance
present in males only
Y linked inheritance
all sons of an infected father are affected by __
Y linked traits: Y linked inheritance
Red-green colorblindness and hemophilia A
X linked inheritance
Maleness and hairy ears
Y linked inheritance
Generally, it manifests only in males. Usual transmission is from mother to son
X-linked Recessive Inheritance
recessive X linked inheritance
- A male with an affected allele on his single X chromosome is __ and cannot transmit the disorder to __ offspring.
- All his daughters would be __
- hemizygous
- male
- obligate carriers
- inherited as an X-linked recessive genetic disorder that, with rare female exceptions, most often affects males.
- inborn error metabolism purine
- deficiency of enzyme
- excessive uric acid in blood
Lesch-Nyhan Syndrome (X linked recessive inheritance)
hen a person who is genetically male (who has one X and one Y chromosome) is resistant to male hormones (called androgens). As a result, the person has some of the physical traits of a woman, but the genetic makeup of a man.
Androgen insensitivity syndrome (AIS)
(X linked recessive inheritance)
- more common in males than in females
- all daughters of an affected father but none of his sons are affected
- any heterozygous mother will pass the trait equally to half her sons and half of her daughters
X-linked dominant inheritance
a disorder of bone mineralization caused due to defects (inherited/acquired) in the renal handling of phosphorus.
Hypophosphatemic rickets (X linked dominant inheritance)
Y-linked Genes( Holandric genes) – in males only (3)
1) porcupine man-skin
2) Webbed toes
3) hypertrichosis
covered with scales; in England (1716); appeared in all six sons but not in daughters
porcupine man-skin (Holandric genes)
web-like connection between 2nd and 3rd toes
webbed toes (holandric genes)
excessive hair development in the outer rim of ears
hypertrichosis (holandric genes)
*In moths and chicken
*Males are __, females are __
Z-Linked Inheritance
- homogametic
- heterogametic
