TOPIC 1 Flashcards
What is another way to say classical genetics?
“Transmission genetics”
What is molecular genetics?
Study of DNA and RNA structure, function, and molecular control of gene expression
Gene
A hereditary unit of information
Gene locus
the position of a gene on the chromosome
Allele
one of two (or more)versions of a gene that differs in sequence and exists at the same loci
Genotype
The combination of alleles for any gene
Phenotype
The observable characteristics, as determined by the genotype
Wild type
The most prevalent phenotype in a population under natural conditions
Mutant (phenotype)
A deviation to the wild-type phenotype as a result from an allelic change in DNA sequence
Are Wild-type and dominant interchangeable terms?
No, wild-types can be dominant or recessive, they are just whatever is most common in that population for that trait.
The significant decrease or complete loss of functional gene product is considered…
A loss of function mutant allele (recessive)
A dominant mutation is what kind of mutation?
gain of function mutation
Incomplete dominance
Where heterozygous individuals display intermediate phenotypes between either homozygous type.
Is a cross between a red and white flower resulting in a pink flower considered codominance?
No, it would be considered incomplete dominance because a detectable expression of both of the parent alleles is not present
AB blood type is an example of what kind of dominance?
Codominance
What does it mean when a gene is haplosufficient?
This means that one wild-type gene copy is sufficient to produce a wild-type phenotype
Haploinsufficiency
A single wild-type allele cannot express the wild-type phenotype on its own, so instead the mutant phenotype is expressed
In the gene A/a, what does the slash represent
That the alleles of the gene are on homologous chromosomes
In the genes A/a ; B/b, what does the semicolon represent
That the A/a and B/b genes are on non-homologous chromosomes
Who observed seven discrete traits through crossing and selfing
Gregor Mendel
Why do all the offspring in F1 of Mendel’s experiment express the dominant phenotype?
Because he used 2 truebreeding parents (one dominant and one recessive), so all the offspring were heterozygous.
What is Mendel’s first law
Equal segregation: Half of gametes carry one member of gene pair, half carry the other member
If a test cross resulted in a 1:1 ratio of dominant and recessive phenotypes, what would be the genotype of the dominant phenotype?
Heterozygous
Rank these chromosomes from order of longest P arm to shortest; metacentric, telocentric and acrocentric
Metacentric, acrocentric, telocentric (P arm was lost)
The P arm is the shorter arm of the chromosome, true or false?
True
