Chapter 4 & 5 Flashcards
excess mucus in lungs, digestive tract, liver; increased susceptibility to infections; dead in early childhood unless treated
Cystic fibrosis (autosomal recessive)
sickled red blood cells, damage to many tissues (homozygous)
Sickle Cell anemia (autosomal recessive)
A disorder that affects the connective tissue in many parts of the body
Marfan Syndrome (autosomal dominant)
Pattern of inheritance that results from genes located on the X chromosome
x-linked
Pattern of inheritance that results from genes located only on the Y chromosome
y-linked
A gene present on the X chromosome that is expressed in males in both the recessive and dominant condition
hemizygous
is an electrolyte disturbance in which there is an abnormally low level of phosphate in the blood.
Hypophosphatemia (x-linked dominant)
Defective color vision caused by reductions or absence of visual pigments
Colorblindness (x-linked recessive)
A group of genetic diseases that cause progressive weakness and loss of muscle mass.
Muscular Dystrophy
Mental deterioration; usually strikes later in life
Huntington’s disease (autosomal dominant)
Disorders resulting from build-up of certain chemicals related to red blood cell proteins.
porphyria (autosomal dominant and recessive)
The probability the phenotype will appear
penetrance
The range of the phenotypes from a given genotype.
expressivity
a medical condition that causes one or more fingers to be permanently bent. It involves fixed flexion deformity of the proximal interphalangeal joints. The fifth finger is always affected.
camptodactyly (autosomal dominant and recessive transmission)
Brenda and David are both heterozygous for cystic fibrosis; they should produce
children of two phenotypes in a 3:1 ratio.
When X-linked traits are considered
- a man’s genotype may be determined from his phenotype.
- a man can inherit them from his maternal grandfather.
Omar (and all other normal males) cannot be heterozygous for ________ genes.
x-linked
Incomplete penetrance refers to
a dominant allele which may not be expressed in the phenotype.
You suspect incomplete penetrance of allele B in a pedigree. You would explain to your client the dominant traits that show incomplete penetrance
can appear in some generations but not in others.
Gene expression refers to
the ability of an allele to affect the phenotype.
Two affected parents give birth to a normal child. This is an indication that the genetic trait involved is
autosomal dominant and are themselves likely to be the children of affected parents.
The human disorder that usually results in death from lung infections is
cystic fibrosis
Mutations in mitochondrial genes
result in a reduction in cellular energy.
- Edwin has a mutation in a mitochondrial gene that causes a vision problem. The gamete that carried this mutation came from Edwin’s_____________.
Mother