gene Flashcards
(26 cards)
what is the Incomplete Dominance ?
a cross between parents with contrasting traits that generate offspring with an intermediate phenotype.
what is the tay sachs disease ?
lysosomal storage disorder caused by a mutation in a gene on chromosome 15 which codes for a iysosomal enzyme called beta hexosaminidase that normally breaks dowm a lipid called GM2 which is found in neurons
what is the codominnce ?
the joint expression of both alleles in a heterozygote ,
The simplest case of multiple alleles occurs when three alternative alleles of one gene exist. This situation is illustrated in the inheritance of the ABO blood groups in humans
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. If an antigen is present on the surface of the person’s red blood cells, it will react with the corresponding antibody and cause clumping,
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the IA and IB alleles are dominant tothe i allele, but codominant to each other.
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The A and B antigens are actually carbohydrate groups (sugars) that are bound to lipid molecules (fatty acids) protruding from the membrane of the red blood cell
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H substance itself contains three sugar molecules ?
Galactose (Gal), N-acetylglucosamine(AcGluNH)Fucose—chemically linked together
what is gene interaction ?
the cellular function of numerous gene products contributes to the development of a common phenotype.
what is pleiotropy ?
where expression of a single gene has multiple phenotypic effects,
what is the expressivity ?
patients with same genotype have varying phenotypes
what is the Penetrance ?
The percentage of individuals that show at least some degree of expression of a mutant genotype
prader willi syndrome ?
maternally drived genes are silenced when THE PATERNAL ALLE IS DELETED
besity intellectual disability
chromosome 15 of paternal
angelman syndrome ?
parenally derived UBE3A IS SILENCED WHEN the maternal allele is deleted or mutated
seizures ataxia intellectual disability
cromosome 15
what is the Crossing over ?
is the swapping of genetic material that occurs in the germ line. During the formation of egg and sperm cells,
Categories of medical Genetic disease:
Chromosome disorders
Single-gene defects
Multifactorial disease with complex inheritance
what is Chromosome disorders ?
an excess
or a deficiency of the genes located on entire chromosomes or chromosome segments.
what is Down syndrome ?
of an extra copy of one chromosome, chromosome 21
what is Single-gene defects ?
pathogenic mutations in individual genes. The mutation may be present on both chromosomes or on only one chromosome of a pair
ex Single-gene defects ?
Cystic fibrosis
Sickle cell anemia
Marfan syndrome
what is the multifactorial disease ?
the majority of diseases in which there is a genetic contribution
ex Multifactorial disease
Hirschsprung disease
Cleft lip and palate
Congenital heart defects
what is gene mean ?
the basic physical and functional unit of heredity are made up of DNA.
what is chromosome mean ?
a long DNA molecule with part or all of the genetic material of an organism
