BIOD351 EXAM 2026 FULL QUESTIONS
WITH SOLUTIONS
◉___________ is the science of heredity and it seeks a precise
explanation of the biological structures and mechanisms that
determine what is inherited and how it is inherited. Answer:
Genetics
◉___________ is the purposeful control over mating by choice of
parents for the next generation. Answer: Artificial Selection
◉___________ is the process whereby both egg and pollen come from
the same plant. Answer: Self Fertilization
◉___________ is a Mendelian Law that states that both alleles must
separate during gamete formation. Answer: Law of Segregation.
◉___________, ___________ and ___________ all were involved in the
rediscovery of Mendel's research. Answer: Corens, deVaries,
Tschermak
◉Normal Male Answer: XY
,◉Normal Female Answer: XX
◉Marriage Answer:
◉Affected Male Answer:
◉___________ Inherited trait expressed only when the controlling gene
is homozygous. Answer: Recessive
◉___________ One contrasting form of a gene. Answer: Allele
◉___________ Symbol for the grandparent of a given individual.
Answer: P2
◉___________ The observable properties of an organism that are under
genetic control. Answer: Phenotype
◉The first offspring from the parents are called. Answer: F1
◉A ___________ is a cross between an unknown and homozygous
recessive. Answer: Testcross
,◉If an individual has 10 gene pairs, how many different gametes can
be formed if three of the gene pairs are homozygous and the
remaining 7 gene pairs are heterozygous? Answer: 128
◉If the parents of a family already have two boys, what is the
probability that the next two offsprings will be girls? Answer: 1/4
◉If some genetically engineered corn plants the dominant gene (BT)
produces a protein that is lethal to certain flying inset pests that cell
the corn plants. It was also found that the pollen could also cause
death in some flying insects. If the corn plant is heterozygous for BT,
what proportion of the pollen would carry the dominant gene?
Answer: 1/2
◉Suppose that in plants, smooth seeds (S) are dominant to wrinkle
seeds (s) and tall plants (T) are dominant to short plants (t). A tall
plant with smooth seeds was backcrossed to a parent that was short
and wrinkle. What proportion of the progeny is expected to e
heterozygous for tall and smooth? Answer: 1/4
◉Suppose that in plants, smooth seeds (S) are dominant to wrinkle
seeds (s) and tall plants (T) are dominant to short plants (t). A tall
plant with smooth seeds was backcrossed to a parent that was short
and wrinkle. What proportion of the progeny is expected to be
homozygous for short and wrinkle? Answer: 1/4
, ◉Sickle cell anemia is a recessive trait in humans. In a cross between
a father who has sickle cell anemia and a mother is heterozygous for
the gene, what is the probability that their first three children will be
normal? Answer: 1/2
◉The dominant trait, Huntington disease causes severe
neural/brain damage at approximately age 4. A female who mother
has Huntington disease, marries a male whose parents are normal. It
is not known if the female has the disease. What is the probability
that their first-born will inherit the gene that causes Huntington
disease? Answer: 25%
◉In a monohybrid cross AA x aa, how many homozygotes are found
among the F2 offspring? Answer: 3
◉In a monohybrid cross AA x aa, how many heterozygotes are fun
among the F2 offspring? Answer: 2
◉In a dihybrid cross AAbb x aaBB, how many homozygotes are
found among the F2 offspring? Answer: 4
◉In a dihybrid cross AABB x aabb, how many heterozygotes at both
gene pairs are found among the F2 offspring? Answer: 4
WITH SOLUTIONS
◉___________ is the science of heredity and it seeks a precise
explanation of the biological structures and mechanisms that
determine what is inherited and how it is inherited. Answer:
Genetics
◉___________ is the purposeful control over mating by choice of
parents for the next generation. Answer: Artificial Selection
◉___________ is the process whereby both egg and pollen come from
the same plant. Answer: Self Fertilization
◉___________ is a Mendelian Law that states that both alleles must
separate during gamete formation. Answer: Law of Segregation.
◉___________, ___________ and ___________ all were involved in the
rediscovery of Mendel's research. Answer: Corens, deVaries,
Tschermak
◉Normal Male Answer: XY
,◉Normal Female Answer: XX
◉Marriage Answer:
◉Affected Male Answer:
◉___________ Inherited trait expressed only when the controlling gene
is homozygous. Answer: Recessive
◉___________ One contrasting form of a gene. Answer: Allele
◉___________ Symbol for the grandparent of a given individual.
Answer: P2
◉___________ The observable properties of an organism that are under
genetic control. Answer: Phenotype
◉The first offspring from the parents are called. Answer: F1
◉A ___________ is a cross between an unknown and homozygous
recessive. Answer: Testcross
,◉If an individual has 10 gene pairs, how many different gametes can
be formed if three of the gene pairs are homozygous and the
remaining 7 gene pairs are heterozygous? Answer: 128
◉If the parents of a family already have two boys, what is the
probability that the next two offsprings will be girls? Answer: 1/4
◉If some genetically engineered corn plants the dominant gene (BT)
produces a protein that is lethal to certain flying inset pests that cell
the corn plants. It was also found that the pollen could also cause
death in some flying insects. If the corn plant is heterozygous for BT,
what proportion of the pollen would carry the dominant gene?
Answer: 1/2
◉Suppose that in plants, smooth seeds (S) are dominant to wrinkle
seeds (s) and tall plants (T) are dominant to short plants (t). A tall
plant with smooth seeds was backcrossed to a parent that was short
and wrinkle. What proportion of the progeny is expected to e
heterozygous for tall and smooth? Answer: 1/4
◉Suppose that in plants, smooth seeds (S) are dominant to wrinkle
seeds (s) and tall plants (T) are dominant to short plants (t). A tall
plant with smooth seeds was backcrossed to a parent that was short
and wrinkle. What proportion of the progeny is expected to be
homozygous for short and wrinkle? Answer: 1/4
, ◉Sickle cell anemia is a recessive trait in humans. In a cross between
a father who has sickle cell anemia and a mother is heterozygous for
the gene, what is the probability that their first three children will be
normal? Answer: 1/2
◉The dominant trait, Huntington disease causes severe
neural/brain damage at approximately age 4. A female who mother
has Huntington disease, marries a male whose parents are normal. It
is not known if the female has the disease. What is the probability
that their first-born will inherit the gene that causes Huntington
disease? Answer: 25%
◉In a monohybrid cross AA x aa, how many homozygotes are found
among the F2 offspring? Answer: 3
◉In a monohybrid cross AA x aa, how many heterozygotes are fun
among the F2 offspring? Answer: 2
◉In a dihybrid cross AAbb x aaBB, how many homozygotes are
found among the F2 offspring? Answer: 4
◉In a dihybrid cross AABB x aabb, how many heterozygotes at both
gene pairs are found among the F2 offspring? Answer: 4
