L16 GENETICS II Flashcards
What is incomplete dominance?
Incomplete dominance is the heterozygous form of an individual where it is the intermediate of the 2 given forms.
Both alleles are expressed in incomplete dominance.
In incomplete dominance, the WHAT always reflects the WHAT?
PHENOTYPE always reflects GENOTYPE.
What is codominance?
Codominance is the phenomenon where two allelez are expressed in separate, distinguishable ways.
What is a non-mendelian trait?
A trait that does not strictly follow the recessive/dominance rules.
An example is human height, it is varied between each person and each person has their own potential height range.
TRUE OR FALSE: one pair of alleles always corresponds to one genotype.
FALSE: many alleles can code for one single gene.
these are polygenic traits!
What is epistasis?
Epistasis is the phemonemnon where individuals can posess a gene that masks other genes on a different locus.
Think of albinism. They carry the dominant epistatic gene and express no pigment.
What is Pleiotropy?
The expression of 2+ traits by a single gene.
.
Marfan syndrome is the mutation of the FBN1 gene and results in varied symptoms: elongated limbs, scoliosis, enlarged aorta, vision issues, connective tissue malfunctions.
What is polygenic inheritance?
Polygenic inheritance is the phenomenon where multiple genes interact to express one unique trait. An example is skin colour and all its variations.
Fill in the blanks.
What is meant by sex-linked inheritance?
Sex-linked inheritance refers to the traits/characteristics influenced by genes found on the X sex chromosome.
All children will inherit which chromosome?
All children inherit the X sex-chromosome from maternal. Their sex will depend on inheriting another X (female) or Y (male) chromosome from paternal.
What is hemizygous?
Individual that has a gene without an allelic counterpart.
IE. Men will not have second allele for genes found on their X chromosome, they are considered hemizygous.
What is polyploidy?
The precense of 2+ sets of chromosomes.
What is aneuploidy?
Anomaly in chromosome numbers.
Name the two types of aneuploidies.
Trisomy: Tri=3
Meaning 1 extra chromosome.
Monosomy: Mono=1
Meaning 1 missing chromosome.