UMKC BIO 108 UNIT 3 EXAM QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026
Characters - Answers distinct heritable features
traits - Answers variations in characters
true-breeding - Answers plants that produce off spring of the same variety when they self-pollinate
Hybridization - Answers mating two contrasting true breeding varieties
F1 generation - Answers the first generation of offspring obtained from an experimental cross of two
organisms
F2 generation - Answers offspring of the F1 generation
P generation - Answers true-breeding parents
dominant trait - Answers a genetic factor that blocks another genetic factor
recessive trait - Answers a genetic factor that is blocked by the presence of a dominant factor
heritable factor - Answers we know call it a gene
Law of Segregation - Answers Mendel's law that states that the pairs of homologous chromosomes
separate in meiosis so that only one chromosome from each pair is present in each gamete
alleles - Answers different versions of a gene
Mendel's 4 concepts - Answers 1. Different versions of genes account for variation
2. Organisms inherit two copies (two alleles) of a
gene; one from each parent
3. If the alleles are different, one will determine
the organism's appearance (dominant allele) and
one is hidden (recessive allele)
4. Law of Segregation - two alleles for a heritable
character segregate from each during gamete
formation; end up in different gametes; they
DON'T BLEND
Homozygous - Answers An organism that has two identical alleles for a trait; "True Breeding"
Heterozygous - Answers An organism that has two different alleles for a trait; not "true breeding"
Phenotype - Answers An organism's physical appearance, or visible traits.
Genotype - Answers genetic makeup of an organism
Test cross - Answers the crossing of an individual of unknown genotype with a homozygous recessive
individual to determine the unknown genotype
dihybrid cross - Answers a cross between two dihybrids can determine wheteher two characters are a
package or are independent
dihybrids - Answers Parents that are heterozygous for two characters.
Law of Independent Assortment - Answers states that each pair of alleles segregates independently of
other pairs of alleles during gamete formation.
Multiplication rule - Answers states that the probability that two or more independent events will
occur together in some specific combination is the product of their individual probabilities.
Addition Rule of Probability - Answers Used to determine the probability that at least one of two
events will occur.
P(A or B) = P(A) + P(B) - P(AB)
Spectrum of Dominance - Answers Alleles can show different degrees of dominance and recessiveness
to each other
Complete Dominance - Answers phenotypes of the heterozygote and dominant homozygote are
identical.
Codominance - Answers two dominant alleles affect the phenotype in separate, distinguishable ways;
Roan Cow
Incomplete Dominance - Answers the phenotype of F1 hybrids is somewhere between the
phenotypes of the two parental varieties; pink flower
Pleiotropy - Answers The ability of a single gene to have multiple effects.
Epistasis - Answers a gene at one locus alters the phenotypic expression of another gene at a second
locus
Quantitative Characters - Answers Characters that vary in the population along a continuum (in
gradations).
, Polygenic Inheritance - Answers An additive effect of two or more genes on a single phenotypic
character.
Norm of Reaction - Answers The range of phenotypes produced by a single genotype, due to
environmental influences.
Multifactorial - Answers genetic and environmental factors into phenotype
Recessively Inherited Disorders - Answers Cystic Fibrosis, Sickle Cell
Dominantly Inherited Disorders - Answers Huntington's disease
Wild-Type - Answers Most common phenotype
Mutant Phenotypes - Answers Traits alternative to the wild type
Linked Genes - Answers Genes located on the same chromosomes that are inherited together
Linkage - Answers occurs when different traits are inherited together more often than they would
have been by chance along; it is assumed that these traits are linked on the same chromosome
Parental Types - Answers Offspring with a phenotype that matches one of the parental phenotypes.
Recombinant Types - Answers Offspring that display different phenotypes from parents
Recombination of Linked Genes - Answers crossing over; breaking of linked genes
Linkage Map - Answers genetic map of a chromosome based on recombination frequencies
Sex-Linked Gene - Answers gene located on a sex chromosome
Barr Body - Answers A dense body formed from a deactivated X chromosome in a female cell
Nondisjunction - Answers pairs of homolouges don't separate normally in meiosis 1 or sisters fail to
separate during meiosis 2
Aneuploidy - Answers Abnormal number of chromosomes resulting from nondisjunction
Trisomic - Answers three copies of a particular chromosome
Monosomic - Answers one copy of a chromosome
Polyploidy - Answers more than two complete sets of chromosomes
Deletion (Chromosomal) - Answers removal of a chromosomal segment
Duplication - Answers repeats a segment
Inversion - Answers reverses a segment within a chromosome
Translocation - Answers moves a segment from one chromosome to another
Genomic Imprinting - Answers a phenomenon in which expression of an allele in offspring depends on
whether the allele is inherited from the male or female parent
DNA - Answers A complex molecule containing the genetic information that makes up the
chromosomes. Is a double helix made up of a nitrogenous base, a pentose sugar, and a phosphate
group.
Nitrogenous Bases - Answers Adenine, Thymine (DNA only), Cytosine, Guanine, Uracil (RNA only)
Base Pairing - Answers principle that bonds in DNA can form only between adenine and thymine
(uracil with RNA) and between guanine and cytosine
Semiconservative Model - Answers Type of DNA replication in which the replicated double helix
consists of one old strand, derived from the old molecule, and one newly made strand. CORRECT
Conservative model - Answers two parental strands reassociate after acting as templates for new
strands thus restoring the parental double helix
Dispersive Model - Answers each strand of both daughter molecules contains a mixture of old and
newly synthesized DNA
Origins of Replication - Answers Site where the two DNA strands are separated and DNA replication
begins
DNA Polymerases - Answers enzymes that catalyse the elongation of new DNA at a replication fork
Replication Fork - Answers A Y-shaped region on a replicating DNA molecule where new strands are
growing.
Nucleoside Triphosphate - Answers each nucleotide that is added to a growing DNA strand
Antiparallel - Answers two strands oriented in opposite directions; double helix of DNA
DNA elongates in what direction? - Answers 5' to 3'; DNA polmerases can only add nucleotides to the
free 3' end
How is the leading strand synthesized? - Answers continuously in a 5' to 3' direction toward the
replication fork
Okazaki fragments - Answers Segments of DNA joined together by DNA ligase to form the Lagging
strand
DNA ligase - Answers enzyme that chemically links DNA fragments together
Characters - Answers distinct heritable features
traits - Answers variations in characters
true-breeding - Answers plants that produce off spring of the same variety when they self-pollinate
Hybridization - Answers mating two contrasting true breeding varieties
F1 generation - Answers the first generation of offspring obtained from an experimental cross of two
organisms
F2 generation - Answers offspring of the F1 generation
P generation - Answers true-breeding parents
dominant trait - Answers a genetic factor that blocks another genetic factor
recessive trait - Answers a genetic factor that is blocked by the presence of a dominant factor
heritable factor - Answers we know call it a gene
Law of Segregation - Answers Mendel's law that states that the pairs of homologous chromosomes
separate in meiosis so that only one chromosome from each pair is present in each gamete
alleles - Answers different versions of a gene
Mendel's 4 concepts - Answers 1. Different versions of genes account for variation
2. Organisms inherit two copies (two alleles) of a
gene; one from each parent
3. If the alleles are different, one will determine
the organism's appearance (dominant allele) and
one is hidden (recessive allele)
4. Law of Segregation - two alleles for a heritable
character segregate from each during gamete
formation; end up in different gametes; they
DON'T BLEND
Homozygous - Answers An organism that has two identical alleles for a trait; "True Breeding"
Heterozygous - Answers An organism that has two different alleles for a trait; not "true breeding"
Phenotype - Answers An organism's physical appearance, or visible traits.
Genotype - Answers genetic makeup of an organism
Test cross - Answers the crossing of an individual of unknown genotype with a homozygous recessive
individual to determine the unknown genotype
dihybrid cross - Answers a cross between two dihybrids can determine wheteher two characters are a
package or are independent
dihybrids - Answers Parents that are heterozygous for two characters.
Law of Independent Assortment - Answers states that each pair of alleles segregates independently of
other pairs of alleles during gamete formation.
Multiplication rule - Answers states that the probability that two or more independent events will
occur together in some specific combination is the product of their individual probabilities.
Addition Rule of Probability - Answers Used to determine the probability that at least one of two
events will occur.
P(A or B) = P(A) + P(B) - P(AB)
Spectrum of Dominance - Answers Alleles can show different degrees of dominance and recessiveness
to each other
Complete Dominance - Answers phenotypes of the heterozygote and dominant homozygote are
identical.
Codominance - Answers two dominant alleles affect the phenotype in separate, distinguishable ways;
Roan Cow
Incomplete Dominance - Answers the phenotype of F1 hybrids is somewhere between the
phenotypes of the two parental varieties; pink flower
Pleiotropy - Answers The ability of a single gene to have multiple effects.
Epistasis - Answers a gene at one locus alters the phenotypic expression of another gene at a second
locus
Quantitative Characters - Answers Characters that vary in the population along a continuum (in
gradations).
, Polygenic Inheritance - Answers An additive effect of two or more genes on a single phenotypic
character.
Norm of Reaction - Answers The range of phenotypes produced by a single genotype, due to
environmental influences.
Multifactorial - Answers genetic and environmental factors into phenotype
Recessively Inherited Disorders - Answers Cystic Fibrosis, Sickle Cell
Dominantly Inherited Disorders - Answers Huntington's disease
Wild-Type - Answers Most common phenotype
Mutant Phenotypes - Answers Traits alternative to the wild type
Linked Genes - Answers Genes located on the same chromosomes that are inherited together
Linkage - Answers occurs when different traits are inherited together more often than they would
have been by chance along; it is assumed that these traits are linked on the same chromosome
Parental Types - Answers Offspring with a phenotype that matches one of the parental phenotypes.
Recombinant Types - Answers Offspring that display different phenotypes from parents
Recombination of Linked Genes - Answers crossing over; breaking of linked genes
Linkage Map - Answers genetic map of a chromosome based on recombination frequencies
Sex-Linked Gene - Answers gene located on a sex chromosome
Barr Body - Answers A dense body formed from a deactivated X chromosome in a female cell
Nondisjunction - Answers pairs of homolouges don't separate normally in meiosis 1 or sisters fail to
separate during meiosis 2
Aneuploidy - Answers Abnormal number of chromosomes resulting from nondisjunction
Trisomic - Answers three copies of a particular chromosome
Monosomic - Answers one copy of a chromosome
Polyploidy - Answers more than two complete sets of chromosomes
Deletion (Chromosomal) - Answers removal of a chromosomal segment
Duplication - Answers repeats a segment
Inversion - Answers reverses a segment within a chromosome
Translocation - Answers moves a segment from one chromosome to another
Genomic Imprinting - Answers a phenomenon in which expression of an allele in offspring depends on
whether the allele is inherited from the male or female parent
DNA - Answers A complex molecule containing the genetic information that makes up the
chromosomes. Is a double helix made up of a nitrogenous base, a pentose sugar, and a phosphate
group.
Nitrogenous Bases - Answers Adenine, Thymine (DNA only), Cytosine, Guanine, Uracil (RNA only)
Base Pairing - Answers principle that bonds in DNA can form only between adenine and thymine
(uracil with RNA) and between guanine and cytosine
Semiconservative Model - Answers Type of DNA replication in which the replicated double helix
consists of one old strand, derived from the old molecule, and one newly made strand. CORRECT
Conservative model - Answers two parental strands reassociate after acting as templates for new
strands thus restoring the parental double helix
Dispersive Model - Answers each strand of both daughter molecules contains a mixture of old and
newly synthesized DNA
Origins of Replication - Answers Site where the two DNA strands are separated and DNA replication
begins
DNA Polymerases - Answers enzymes that catalyse the elongation of new DNA at a replication fork
Replication Fork - Answers A Y-shaped region on a replicating DNA molecule where new strands are
growing.
Nucleoside Triphosphate - Answers each nucleotide that is added to a growing DNA strand
Antiparallel - Answers two strands oriented in opposite directions; double helix of DNA
DNA elongates in what direction? - Answers 5' to 3'; DNA polmerases can only add nucleotides to the
free 3' end
How is the leading strand synthesized? - Answers continuously in a 5' to 3' direction toward the
replication fork
Okazaki fragments - Answers Segments of DNA joined together by DNA ligase to form the Lagging
strand
DNA ligase - Answers enzyme that chemically links DNA fragments together
