BIO 325 Exam 1 Review Questions and
Answers 2026 Update
Genes -Correct Answer ✔-basic units of biological information
Heredity -Correct Answer ✔-the way genes transmit physiological, anatomical,
and behavioral traits from parents to offspring
What does P stand for? -Correct Answer ✔-Parental generation
What does F1 stand for? -Correct Answer ✔-first filial generation
•progeny of the parental generation
Monohybrid crosses -Correct Answer ✔-hybrids for a single trait
What does F2 stand for? -Correct Answer ✔-second filial generation
•progeny of the F1 generation
Alleles -Correct Answer ✔-alternative forms of a single gene
Monohybrids -Correct Answer ✔-Individuals having two different alleles for a
single trait
Law of Segregation -Correct Answer ✔-Mendel's first law, states that the two
alleles for each trait separate (segregate) during gamete formation, and then unite
at random, one from each parent, at fertilization
Somatic cells -Correct Answer ✔-body cells
•undergo mitosis
•2n=46 chromosomes (humans)
, Product Rule -Correct Answer ✔-the probability of two or more independent
events occurring together is the product of the probabilities that each event will
occur by itself
EX:
Probability of event 1 and event 2 =
Probability of event 1 × probability of event 2.
Sum Rule -Correct Answer ✔-states that the probability of either of two such
mutually exclusive events occurring is the sum of their individual probabilities
EX:
Probability of event 1 or event 2 =
Probability of event 1 + probability of event 2.
Dihybrid -Correct Answer ✔-heterozygous for two genes at the same time
Law of independent Assortment -Correct Answer ✔-the random distribution of
alleles of different genes during gamete formation
•perfect ratio~ 1:1:1:1
•According to this law, crosses between Aa Bb dihybrids will generate progeny
with a phenotypic ratio of 9 (A- B-) : 3 (A- bb) : 3 (aa B-) : 1 (aa bb).
Incomplete Dominance -Correct Answer ✔-the hybrid does not resemble either
pure-breeding parent
Co-dominant -Correct Answer ✔-both traits show up equally in the heterozygote's
phenotype
When two or more wild-type alleles (common variants) exist for a gene, the gene
is _____; a gene with only one wild-type allele is _____. -Correct Answer ✔-
polymorphic, monomorphic
Answers 2026 Update
Genes -Correct Answer ✔-basic units of biological information
Heredity -Correct Answer ✔-the way genes transmit physiological, anatomical,
and behavioral traits from parents to offspring
What does P stand for? -Correct Answer ✔-Parental generation
What does F1 stand for? -Correct Answer ✔-first filial generation
•progeny of the parental generation
Monohybrid crosses -Correct Answer ✔-hybrids for a single trait
What does F2 stand for? -Correct Answer ✔-second filial generation
•progeny of the F1 generation
Alleles -Correct Answer ✔-alternative forms of a single gene
Monohybrids -Correct Answer ✔-Individuals having two different alleles for a
single trait
Law of Segregation -Correct Answer ✔-Mendel's first law, states that the two
alleles for each trait separate (segregate) during gamete formation, and then unite
at random, one from each parent, at fertilization
Somatic cells -Correct Answer ✔-body cells
•undergo mitosis
•2n=46 chromosomes (humans)
, Product Rule -Correct Answer ✔-the probability of two or more independent
events occurring together is the product of the probabilities that each event will
occur by itself
EX:
Probability of event 1 and event 2 =
Probability of event 1 × probability of event 2.
Sum Rule -Correct Answer ✔-states that the probability of either of two such
mutually exclusive events occurring is the sum of their individual probabilities
EX:
Probability of event 1 or event 2 =
Probability of event 1 + probability of event 2.
Dihybrid -Correct Answer ✔-heterozygous for two genes at the same time
Law of independent Assortment -Correct Answer ✔-the random distribution of
alleles of different genes during gamete formation
•perfect ratio~ 1:1:1:1
•According to this law, crosses between Aa Bb dihybrids will generate progeny
with a phenotypic ratio of 9 (A- B-) : 3 (A- bb) : 3 (aa B-) : 1 (aa bb).
Incomplete Dominance -Correct Answer ✔-the hybrid does not resemble either
pure-breeding parent
Co-dominant -Correct Answer ✔-both traits show up equally in the heterozygote's
phenotype
When two or more wild-type alleles (common variants) exist for a gene, the gene
is _____; a gene with only one wild-type allele is _____. -Correct Answer ✔-
polymorphic, monomorphic
