Chapter 4 Flashcards
Dominance of one allele over another is determined by the _______ of that allele
protein product
The overall phenotype is the consequence of the _______ of the protein products of the alleles of the gene
activities
_______: meaning that one copy of an allele is enough for normal function
Haplosufficient
_______: meaning that one copy of an allele is not enough for normal function
Haploinsufficient
A _______ phenotype is always produced when an organism has 2 copies of the wild type allele
wild-type
_______ mutation = when the gene product acquires a new function or shows an increased level of wild-type activity
gain-of-function
_______ mutation = when there is a significant decrease or complete loss of functional gene product
loss-of-function
loss-of-function mutations that produce no functional protein product is called _______ or _______; often these are lethal when homozygous
null mutation
amorphic mutation
loss-of-function mutations that result in a partial loss of function are called _______ or _______; the severity of the phenotype depends on the level of activity of the mutation
leaky mutation
hypomorphic mutation
Multimeric proteins, composed of 2 or more polypeptides that join together to form a functioning protein, are particularly subject to _______
dominant negative mutations
Dominant negative mutations are dominant due to the loss of function of the multimeric protein complex due to an _______ change in one subunit
- these are negative mutations due to their “_______” on the protein as a whole
amino acid
spoiler effect
Gain of function mutations can be _______ or ________
hypermorphic
neomorphic
_______ mutations produce more gene activity than the wild-type
hypermorphic
_______ mutations acquire novel gene activities not in the wild-type
neomorphic
_______ is when heterozygous individuals display intermediate phenotypes between either homozygous type
incomplete dominance
_______ produces heterozygotes with a phenotype different than that of either homozygote
Codominance
_______: RBC’s display A antigen on surface
_______: RBC’s display B antigen on surface
_______: RBC’s display A and B antigen on surface
_______: RBC’s display neither A or B antigen on surface
1) Type A blood
2) Type B blood
3) Type AB blood
4)Type O blood
Blood group antigens are _______ with the lipid portion anchored in the RBC membrane
glycolipids
What turns the H antigen into A antigen? B antigen?
A: A transferase
-adds N-acetylgalactosamine to 5 sugar molecule
B: B transferase
-adds galactose to 5 sugar molecule
The __-gene is responsible for coat color in mammals, and it produces an allelic series
C
What are the four forms of the C gene in mammal coat color? What color do they correspond with?
1) C: full
2) C^ch: chinchilla
3) C^h: himalayan
4) c: albino
The C allele produces a _______ enzyme that is 100% active making it _______
tyrosine
haplosufficient
the c^ch allele produces an enzyme that is less than 20% active making it _______
hypomorphic
the c^h allele produces an enzyme that is _______, it is also _______
temperature-sensitive
Hypomorphic
the c allele produces no functional enzyme making it _______
amorphic
_______: single-gene mutations that are so detrimental that they cause death in the organism
lethal mutation
the phenotype ratio for a organisms with a lethal allele is _______
1/3 homozygous
2/3 heterozygous
_______ produces a protein essential for mouse development
Raly
Dominant lethal alleles can sidestep natural selection if they have a _______
delayed age of onset
A prominent example of delayed age of onset is _______
Huntington’s disease
_______: where both sexes carry the genes for traits, but they are expressed in only one sex
- Genotype doesn’t really matter
sex-limited traits
_______ are those in which the phenotype corresponding to a particular genotype differs depending on the sex of the organism
sex-influenced traits
_______ = observed phenotype is consistent with the genotype
penetrance
_______ = the phenotype associated with the genotype is not visible
non-penetrance
_______ = when the expected phenotype is always expressed from a particular genotype
fully penetrant
_______ = traits/genotypes that are nonpenetrant in a portion of the population
incomplete (variable) penetrance
_______ is an autosomal dominant condition in which affected individuals have more than 5 fingers and toes. The dominant allele is _______
polydactyly
non-penetrant
_______ is seen in individuals who show a phenotype but to a varying degree of severity
variable expressivity
The human autosomal recessive condition, PKU, is an example of _______
environmental modification
_______ is the alteration of multiple distinct traits by a mutation in a single gene
pleiotropy
the collaboration of multiple genes in the production of a single phenotypic characteristic or group of related characteristics is termed _______
gene interactions
_______ involve biosynthesis of complex compounds
anabolic pathways
_______ involve degradation of complex compounds
catabolic pathways
_______: the alleles of one gene modify or prevent the expression of alleles of another gene
Epistasis
No gene interaction from crossing the F1 generation will lead to a phenotype ratio of _______
9:3:3:1
_______: when 2 genes work together to produce a single gene product
complementary gene interaction
Complementary gene interaction from crossing the F1 generation will lead to a phenotype ratio of _______
9:7
_______: when two genes duplicate each others activity, in which a dominant allele at either locus gives rise to the wild type phenotype
duplicate gene action
Duplicate gene interaction from crossing the F1 generation will lead to a phenotype ratio of _______
15:1
Dominant gene interaction from crossing the F1 generation will lead to a phenotype ratio of _______
9:6:1
In _______, homozygosity for the recessive alleles at one locus mask the phenotypic expression of the alleles at a second locus
recessive epistasis
A recessive epistasis gene interaction from crossing the F1 generation will lead to a phenotype ratio of _______
9:3:4
In _______, a dominant allele at one locus will mask the phenotypic expression of the alleles at a second locus
dominant epistasis
A dominant epistasis gene interaction from crossing the F1 generation will lead to a phenotype ratio of _______
12:3:1
In _______, a dominant allele at one locus completely suppresses the phenotypic expression of the alleles at a second locus
dominant suppression
A dominant suppression gene interaction from crossing the F1 generation will lead to a phenotype ratio of _______
13:3
Genetic _______ analysis is performed by mating two pure-breeding mutants for similar mutant phenotypes and observing the F1 generation.
- IF phenotypically wild type are obtained: mutations are on ______ genes
- IF phenotypically mutants are obtained: mutations are on ______ genes
complementation
different
same
_______ described conditions when mutations in different genes can produce the same or very similar mutant phenotypes
genetic heterogeneity
Using terminology from the chapter, characterize the 12 colonies that grow on minimal media (_______) and the 3 colonies that do not (_______)
prototrophs
auxotrophs
Three colonies that do not grow on the minimal medium and are replica-plated to minimal medium plus serine, then all 3 colonies grow. Characterize these 3 colonies.
serine requiring (dependant) auxotrophs
