BIO 181 FINAL LATEST ACTUAL EXAM WITH
VERIFIED QUESTIONS & CORRECT ANSWERS (2026)
●● what does it mean for an allele to be dominant and how does it
interact with recessive alleles
Answer: a dominant allele masks the expression of another allele in a
heterozygote
●● explain the difference between homozygous and heterozygous
individuals
Answer: homozygous individuals have two of the same alleles, while
heterozygous individuals have two different alleles
●● what does it mean for an organism to be true-breeding?
Answer: a true-breeding organism always produces offspring with the
same traits as the parent when self-crossed
●● what does F1 generation mean in genetics? How does it differ from
the parental generation?
Answer: The F1 generation is the first filial generation of offsrping and
differs from the parental generation because it is the offspring produced
from the original parents
, ●● State Mendel's Law of Segregation and explain what happens to
alleles during gamete formation
Answer: Mendel's Law of Segregation states that two alleles for a trait
separate during gamete formation, and each gamete recieves one allele.
●● Describe Mendel's Law of Independent Assortment and explain how
meiosis illustrates this law.
Answer: Mendel's Law of Independent Assortment states that genes
assort independently during gamete formation. Random alignment of
homologous chromosome pairs during metaphase I illustrates this law.
●● What is a test cross, and when would a geneticist use one?
Answer: to determine if an organism showing a dominants trait is
homozygous or heterozygous
●● in a monohybrid cross between two heterozygous individuals: what
is the expected phenotypic ratio?
Answer: 3:1 dominant:recessive
●● In a monohybrid cross between two heterozygous individuals: what
is the expected genotypic ratio?
Answer: 1:2:1 homozygous dominant:heterozygous:homozygous
recessice
VERIFIED QUESTIONS & CORRECT ANSWERS (2026)
●● what does it mean for an allele to be dominant and how does it
interact with recessive alleles
Answer: a dominant allele masks the expression of another allele in a
heterozygote
●● explain the difference between homozygous and heterozygous
individuals
Answer: homozygous individuals have two of the same alleles, while
heterozygous individuals have two different alleles
●● what does it mean for an organism to be true-breeding?
Answer: a true-breeding organism always produces offspring with the
same traits as the parent when self-crossed
●● what does F1 generation mean in genetics? How does it differ from
the parental generation?
Answer: The F1 generation is the first filial generation of offsrping and
differs from the parental generation because it is the offspring produced
from the original parents
, ●● State Mendel's Law of Segregation and explain what happens to
alleles during gamete formation
Answer: Mendel's Law of Segregation states that two alleles for a trait
separate during gamete formation, and each gamete recieves one allele.
●● Describe Mendel's Law of Independent Assortment and explain how
meiosis illustrates this law.
Answer: Mendel's Law of Independent Assortment states that genes
assort independently during gamete formation. Random alignment of
homologous chromosome pairs during metaphase I illustrates this law.
●● What is a test cross, and when would a geneticist use one?
Answer: to determine if an organism showing a dominants trait is
homozygous or heterozygous
●● in a monohybrid cross between two heterozygous individuals: what
is the expected phenotypic ratio?
Answer: 3:1 dominant:recessive
●● In a monohybrid cross between two heterozygous individuals: what
is the expected genotypic ratio?
Answer: 1:2:1 homozygous dominant:heterozygous:homozygous
recessice
