Lecture 30 Flashcards
Define and give an example of incomplete dominance in flowers
phenotype of a trait reflects the amount of gene that an allele produces (not all or nothing). Example = white + red flower = pink flower if 1/2 gametes code white and other 1/2 code red
define and give an example of codominance
both alleles have their own effect and at the same time. Example = blood type
Who is the universal donor of blood? The receiver?
Donor is O, receiver is AB
what is the enzyme called that blood type alleles encode? What does this put onto the surface of a red blood cell?
transferase, carbohydrate
Define, explain the mechanism for, and give an example of epistasis. What other pattern is it mistaken for? What is the phenotypic ratio?
the product of 1 gene alters the phenotypic expression of another gene. The gene whose expression varies is for something like color, the epistatic gene codes for a txn factor enzyme that activates gene expression, letting the pigment exist. Example is in lab coat color (black, brown, golden). Can look like incomplete dominance, in a 9:3:4 ratio
Define and explain polygenic inheritance. What are the 2 most common examples?
Where 2 or more genes influence a single phenotype. If a gene encodes a slightly more active enzyme (for whatever reason) it will dominate. Due to difference in protein sequence = protein function. Skin color and height
in a pedigree, what depicts a man/woman/exhibitor of a trait?
man = square, woman = circle, filled in shape = exhibits trait
What kind of disorder is albinism? Explain the mechanism
recessive disorder, 1 gene that codes for a melanocyte (skin cell) enzyme is not functional.
what kind of disorder is achondroplasia? Explain the mechanism
aka dwarfism…dominant disorder. has an overly active growth factor receptor that converts a baby’s cartilage to bone too soon. Lethal for homozygous dominant
Cystic fibrosis is an example of what? What is the mechanism for CF?
Pleitropy. Chloride channel responsible for getting chloride (and water) out of respiratory cells, so the lining gets very thick. Hard to breathe, die by 30 of respiratory disease
What is pleitropy? what are the 3 examples we learned in class?
It is where a single gene effects multiple phenotypes for an individual. Cystic fibrosis, huntington’s, and Sicke cell
Sickle Cell is an example of what? What is the mechanism for it?
Pleitropy, allele that encodes for a normal form of hemoglobin is mutated, so the RBC cant get thru
what are the addition and multiplication rules according to the laws of probability?
the probability of 2 mutually exclusive events occurring is the sum of each of their own probabilities. The probability of to independent evens occurring is the product of each of their probabilities.
