Auburn BIOL 3001 Midterm Exam with
Solved Solutions 2026-2027 Updated.
Pedigree - Answer chart that shows the presence or absence of a trait according to the
relationships within a family across several generations
Complete Penetrance - Answer The gene or genes for a trait are expressed in all the
population who have the genes
Incomplete Penetrance - Answer the genetic trait is expressed in only part of the population
3 assumptions when determining the mode of inheritance - Answer 1. The trait displays
Complete Penetrance.
2. The trait is considered Rare-in-Population.
3. The traits you examine are not Y-Linked.
Pedigree symbols: diamond - Answer gender not specified
Pedigree symbols: line through square, circle, or diamond - Answer deceased individual
Pedigree symbols: have filled square or circle - Answer carrier individual (usually
heterozygous)
Pedigree symbols: two shapes branching from the same node - Answer dizygotic twins
Pedigree symbols: two shapes branching from the same node with extra line connecting them -
Answer monozygotic twins
Pedigree symbols: black arrow pointing to square, circle, or diamond on tree - Answer
proband: individual who prompted pedigree
Pedigree symbols: Brackets around an individual - Answer adopted individual
Clues indicating autosomal recessive - Answer -parents unaffected
-skips a generation / disappear and reappear across generations
, indicate autosomal dominant - Answer -appears in every generation
-at least one affected parent
-usually have an affected offspring
indicate x-linked dominant trait - Answer -More females than males
-affected person must have at least one affected parent
-trait cannot skip a generation
indicate sex-linked recessive trait - Answer -more males than females
-most affected males usually receive the allele from their mother
-affected females must have an affected father
indicate holandric (Y-linked) trait - Answer -males only in humans (mammals)
-affected male must have an affected father
-very rare
mode of inheritance - Answer Manner in which a genetic trait or disorder is passed from one
generation to the next
How many chromosomes do fruit flies have? - Answer 2N=8 (4 pairs)
Sex-determination in fruit flies - Answer lygaeus mode, but dependent on actual number of X
chromosomes
Homolog - Answer a gene inherited in two species from a common ancestor
Pure A cross (AAxAA) - Answer All AA; All dominant
Pure a cross (aaxaa) - Answer All aa; All recessive
Parental (P1) Cross (AA x aa) - Answer All Aa; shows dominant phenotype
F Cross (AaxAa) - Answer 1AA:2Aa:1aa; 3A_:1aa
Recessive Backcross (Aaxaa) - Answer 1 AA : 1 aa; 1 Aa : 1 aa
Solved Solutions 2026-2027 Updated.
Pedigree - Answer chart that shows the presence or absence of a trait according to the
relationships within a family across several generations
Complete Penetrance - Answer The gene or genes for a trait are expressed in all the
population who have the genes
Incomplete Penetrance - Answer the genetic trait is expressed in only part of the population
3 assumptions when determining the mode of inheritance - Answer 1. The trait displays
Complete Penetrance.
2. The trait is considered Rare-in-Population.
3. The traits you examine are not Y-Linked.
Pedigree symbols: diamond - Answer gender not specified
Pedigree symbols: line through square, circle, or diamond - Answer deceased individual
Pedigree symbols: have filled square or circle - Answer carrier individual (usually
heterozygous)
Pedigree symbols: two shapes branching from the same node - Answer dizygotic twins
Pedigree symbols: two shapes branching from the same node with extra line connecting them -
Answer monozygotic twins
Pedigree symbols: black arrow pointing to square, circle, or diamond on tree - Answer
proband: individual who prompted pedigree
Pedigree symbols: Brackets around an individual - Answer adopted individual
Clues indicating autosomal recessive - Answer -parents unaffected
-skips a generation / disappear and reappear across generations
, indicate autosomal dominant - Answer -appears in every generation
-at least one affected parent
-usually have an affected offspring
indicate x-linked dominant trait - Answer -More females than males
-affected person must have at least one affected parent
-trait cannot skip a generation
indicate sex-linked recessive trait - Answer -more males than females
-most affected males usually receive the allele from their mother
-affected females must have an affected father
indicate holandric (Y-linked) trait - Answer -males only in humans (mammals)
-affected male must have an affected father
-very rare
mode of inheritance - Answer Manner in which a genetic trait or disorder is passed from one
generation to the next
How many chromosomes do fruit flies have? - Answer 2N=8 (4 pairs)
Sex-determination in fruit flies - Answer lygaeus mode, but dependent on actual number of X
chromosomes
Homolog - Answer a gene inherited in two species from a common ancestor
Pure A cross (AAxAA) - Answer All AA; All dominant
Pure a cross (aaxaa) - Answer All aa; All recessive
Parental (P1) Cross (AA x aa) - Answer All Aa; shows dominant phenotype
F Cross (AaxAa) - Answer 1AA:2Aa:1aa; 3A_:1aa
Recessive Backcross (Aaxaa) - Answer 1 AA : 1 aa; 1 Aa : 1 aa
