Genetics Exam test queries and
answers graded A+
Gene - ANS✅✅molecular unit of heredity of a living organism. comprised of a stretch of DNA.
genes specify all proteins and functional RNA chains. all organisms have genes that correspond to
various biological traits.
Genome - ANS✅✅an organism's complete set of DNA, including all of its genes. in humans, a copy
of the entire genome is contained in every cell with a nucleus.
Allele - ANS✅✅one of 2 or more versions of a gene - an individual inherits one from each parent.
Wild - ANS✅✅type - a strain, gene, or characteristic that prevails among individuals in natural
conditions.
Mutant - ANS✅✅organism/genetic character resulting from a base-pair sequence change within
the DNA of a gene or chromosome of an organism.
Trait - ANS✅✅a genetically determined characteristic.
Self (Self cross) - ANS✅✅mating of an individual with itself.
Outcross - ANS✅✅mating to an unrelated individual of the same species or breed.
True breeding line - ANS✅✅organism that always passes down a certain phenotypic trait must be
homozygous for every trait for which it is "true-breeding."
Monohybrid cross - ANS✅✅mating between individuals who have different alleles at one genetic
locus of interest.
Genotype - ANS✅✅genetic makeup of a cell (letter representation - AA, aa, Aa)
Phenotype - ANS✅✅outward expression of a genotype (physical appearance)
, Dominant - ANS✅✅a trait that is expressed over another trait
Recessive - ANS✅✅only expressed if homozygous
Codominant - ANS✅✅both traits appear together (i.e. a red flower and a white flower would
produce red and white spotted offspring)
Partially dominant - ANS✅✅traits combine to form a third phenotype (i.e. a red flower and a white
flower would produce pink offspring)
Segregation - ANS✅✅the separation of pairs of alleles at meiosis and their independent
transmission via separate gametes.
Law of Segregation - ANS✅✅allele pairs separate or segregate during gamete formation and
randomly unite at fertilization
Loss-of-function allele - ANS✅✅results in the gene product having less or no function (mostly
recessive)
Null allele - ANS✅✅mutant copy of a gene that completely lacks the gene's normal function
Gain-of-function allele - ANS✅✅gene product gains a new function (mostly dominant)
Chromosome - ANS✅✅a packaged and organized complex of macromolecules consisting of DNA,
protein, and RNA.
Chromatid (Sister chromatids) - ANS✅✅one copy of a duplicated chromosome.
Dyad - ANS✅✅a pair of sister chromatids.
Homologous (Homolog) - ANS✅✅gene related to a second gene by descent from a common
ancestral DNA sequence.
answers graded A+
Gene - ANS✅✅molecular unit of heredity of a living organism. comprised of a stretch of DNA.
genes specify all proteins and functional RNA chains. all organisms have genes that correspond to
various biological traits.
Genome - ANS✅✅an organism's complete set of DNA, including all of its genes. in humans, a copy
of the entire genome is contained in every cell with a nucleus.
Allele - ANS✅✅one of 2 or more versions of a gene - an individual inherits one from each parent.
Wild - ANS✅✅type - a strain, gene, or characteristic that prevails among individuals in natural
conditions.
Mutant - ANS✅✅organism/genetic character resulting from a base-pair sequence change within
the DNA of a gene or chromosome of an organism.
Trait - ANS✅✅a genetically determined characteristic.
Self (Self cross) - ANS✅✅mating of an individual with itself.
Outcross - ANS✅✅mating to an unrelated individual of the same species or breed.
True breeding line - ANS✅✅organism that always passes down a certain phenotypic trait must be
homozygous for every trait for which it is "true-breeding."
Monohybrid cross - ANS✅✅mating between individuals who have different alleles at one genetic
locus of interest.
Genotype - ANS✅✅genetic makeup of a cell (letter representation - AA, aa, Aa)
Phenotype - ANS✅✅outward expression of a genotype (physical appearance)
, Dominant - ANS✅✅a trait that is expressed over another trait
Recessive - ANS✅✅only expressed if homozygous
Codominant - ANS✅✅both traits appear together (i.e. a red flower and a white flower would
produce red and white spotted offspring)
Partially dominant - ANS✅✅traits combine to form a third phenotype (i.e. a red flower and a white
flower would produce pink offspring)
Segregation - ANS✅✅the separation of pairs of alleles at meiosis and their independent
transmission via separate gametes.
Law of Segregation - ANS✅✅allele pairs separate or segregate during gamete formation and
randomly unite at fertilization
Loss-of-function allele - ANS✅✅results in the gene product having less or no function (mostly
recessive)
Null allele - ANS✅✅mutant copy of a gene that completely lacks the gene's normal function
Gain-of-function allele - ANS✅✅gene product gains a new function (mostly dominant)
Chromosome - ANS✅✅a packaged and organized complex of macromolecules consisting of DNA,
protein, and RNA.
Chromatid (Sister chromatids) - ANS✅✅one copy of a duplicated chromosome.
Dyad - ANS✅✅a pair of sister chromatids.
Homologous (Homolog) - ANS✅✅gene related to a second gene by descent from a common
ancestral DNA sequence.
