BIO 100 FINAL EXAM REAL EXAM 2026 | ALL QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) | UPDATED VERSION
Question 1
The visible or measurable features of an individual, such as hair color, height, or the presence of
a specific protein, are referred to as the:
A) Genotype
B) Allele
C) Phenotype
D) Chromotype
E) Karyotype
Correct Answer: C) phenotype
Rationale: The phenotype represents the physical expression or characteristics of an
organism that result from the interaction of its genetic makeup (genotype) and the
environment. While the genotype is the set of genes an organism carries, the phenotype is
what we actually see or measure, ranging from microscopic protein functions to
macroscopic traits like eye color.
Question 2
A normal human somatic cell contains 46 chromosomes. How many chromosomes are found in a
human sperm cell?
A) 46
B) 23
C) 92
D) 44
E) 22
Correct Answer: B) 23
Rationale: Human gametes (sperm and egg cells) are haploid, meaning they contain half the
number of chromosomes found in diploid somatic (body) cells. This reduction is necessary
so that when fertilization occurs, the resulting zygote regains the correct diploid number of
46 (23 from the father and 23 from the mother).
Question 3
In genetics, an allele that reveals itself in the phenotype only if the organism has two copies of
, 2
that specific allele is known as a _____ allele.
A) Dominant
B) Heterozygous
C) Recessive
D) Homozygous
E) Codominant
Correct Answer: C) recessive
Rationale: Recessive alleles are masked by dominant alleles in a heterozygous state. For a
recessive trait to be expressed in the phenotype, the individual must be homozygous
recessive, meaning they inherited the recessive allele from both parents. An example is
cystic fibrosis or albinism.
Question 4
If sickle-cell anemia is present in some of your family members, which of the following
represents information you could obtain from current medical research on the condition?
A) The specific genetic mutation responsible for the misshapen hemoglobin.
B) The probability of passing the trait to future offspring.
C) Treatment options to manage pain crises associated with the disease.
D) The evolutionary link between the sickle-cell trait and malaria resistance.
E) All of these
Correct Answer: E) all of these
Rationale: Scientific research provides a holistic understanding of genetic conditions. This
includes the molecular cause (mutations in the beta-globin gene), the inheritance patterns
(autosomal recessive logic), clinical management strategies, and the population genetics
(the "heterozygote advantage" in regions with malaria).
Question 5
A person is diagnosed with a cystic fibrosis (CF) phenotype. What does this indicate about the
CFTR protein encoded by the cystic fibrosis gene in their lung cells?
A) The protein is working at double efficiency.
B) The protein is functional but in the wrong location.
, 3
C) The protein is not functional or is entirely absent.
D) The protein has been converted into a lipid.
E) The protein is only functional during sleep.
Correct Answer: C) the protein is not functional
Rationale: Cystic fibrosis is caused by mutations in the CFTR gene, which normally codes
for a protein that functions as a chloride channel in cell membranes. In individuals with the
CF phenotype, the mutation results in a protein that cannot properly transport chloride
ions, leading to the thick, sticky mucus characteristic of the disease.
Question 6
Which biological principle states that alleles of different genes are distributed independently of
one another during the process of meiosis?
A) Law of Segregation
B) Principle of Dominance
C) Independent Assortment
D) Linkage Disequilibrium
E) Genetic Recombination
Correct Answer: C) independent assortment
Rationale: Independent assortment occurs during Meiosis I when homologous chromosome
pairs line up randomly at the metaphase plate. This means the inheritance of an allele for
one trait (e.g., hair color) does not affect the inheritance of an allele for another trait (e.g.,
height), provided the genes are on different chromosomes.
Question 7
Albinism is a condition where a person lacks melanin pigmentation. If two parents with normal
pigmentation have a child with albinism, what does this suggest about the albinism trait?
A) It is a dominant trait.
B) It is a recessive trait.
C) It is a spontaneous mutation that only happens in males.
D) It is caused by an extra chromosome.
E) It is an environmental condition caused by diet.
, 4
Correct Answer: B) recessive
Rationale: If a trait appears in a child but is not present in either parent, the parents must
be "carriers" (heterozygous). This is the definition of an autosomal recessive inheritance
pattern, where the dominant "normal" allele masks the recessive "albino" allele in the
parents.
Question 8
In the study of cystic fibrosis (CF), researchers have found that the severity of the disease is
influenced by "modifier genes." Which body system has been found to harbor the most genes
influencing CF severity?
A) The skeletal system
B) The nervous system
C) The immune system
D) The muscular system
E) The integumentary system
Correct Answer: C) immune system
Rationale: While CF primarily affects mucus production in the lungs and digestive tract, the
body's response to the resulting chronic infections is mediated by the immune system.
Genetic variations in how the immune system handles inflammation and bacteria
significantly dictate how severe the lung damage will be for a specific patient.
Question 9
A normal gene encodes a protein of 350 amino acids. A mutation occurs that creates a "stop"
codon early, resulting in a protein with only the first 120 amino acids. What is the likely fate of
this mutant allele's product?
A) The protein may fail to fold correctly.
B) The protein may be degraded by the cell.
C) The protein will be unable to perform its original function.
D) The truncated protein may be shorter than the original.
E) All of these
ANSWERS (VERIFIED ANSWERS) | UPDATED VERSION
Question 1
The visible or measurable features of an individual, such as hair color, height, or the presence of
a specific protein, are referred to as the:
A) Genotype
B) Allele
C) Phenotype
D) Chromotype
E) Karyotype
Correct Answer: C) phenotype
Rationale: The phenotype represents the physical expression or characteristics of an
organism that result from the interaction of its genetic makeup (genotype) and the
environment. While the genotype is the set of genes an organism carries, the phenotype is
what we actually see or measure, ranging from microscopic protein functions to
macroscopic traits like eye color.
Question 2
A normal human somatic cell contains 46 chromosomes. How many chromosomes are found in a
human sperm cell?
A) 46
B) 23
C) 92
D) 44
E) 22
Correct Answer: B) 23
Rationale: Human gametes (sperm and egg cells) are haploid, meaning they contain half the
number of chromosomes found in diploid somatic (body) cells. This reduction is necessary
so that when fertilization occurs, the resulting zygote regains the correct diploid number of
46 (23 from the father and 23 from the mother).
Question 3
In genetics, an allele that reveals itself in the phenotype only if the organism has two copies of
, 2
that specific allele is known as a _____ allele.
A) Dominant
B) Heterozygous
C) Recessive
D) Homozygous
E) Codominant
Correct Answer: C) recessive
Rationale: Recessive alleles are masked by dominant alleles in a heterozygous state. For a
recessive trait to be expressed in the phenotype, the individual must be homozygous
recessive, meaning they inherited the recessive allele from both parents. An example is
cystic fibrosis or albinism.
Question 4
If sickle-cell anemia is present in some of your family members, which of the following
represents information you could obtain from current medical research on the condition?
A) The specific genetic mutation responsible for the misshapen hemoglobin.
B) The probability of passing the trait to future offspring.
C) Treatment options to manage pain crises associated with the disease.
D) The evolutionary link between the sickle-cell trait and malaria resistance.
E) All of these
Correct Answer: E) all of these
Rationale: Scientific research provides a holistic understanding of genetic conditions. This
includes the molecular cause (mutations in the beta-globin gene), the inheritance patterns
(autosomal recessive logic), clinical management strategies, and the population genetics
(the "heterozygote advantage" in regions with malaria).
Question 5
A person is diagnosed with a cystic fibrosis (CF) phenotype. What does this indicate about the
CFTR protein encoded by the cystic fibrosis gene in their lung cells?
A) The protein is working at double efficiency.
B) The protein is functional but in the wrong location.
, 3
C) The protein is not functional or is entirely absent.
D) The protein has been converted into a lipid.
E) The protein is only functional during sleep.
Correct Answer: C) the protein is not functional
Rationale: Cystic fibrosis is caused by mutations in the CFTR gene, which normally codes
for a protein that functions as a chloride channel in cell membranes. In individuals with the
CF phenotype, the mutation results in a protein that cannot properly transport chloride
ions, leading to the thick, sticky mucus characteristic of the disease.
Question 6
Which biological principle states that alleles of different genes are distributed independently of
one another during the process of meiosis?
A) Law of Segregation
B) Principle of Dominance
C) Independent Assortment
D) Linkage Disequilibrium
E) Genetic Recombination
Correct Answer: C) independent assortment
Rationale: Independent assortment occurs during Meiosis I when homologous chromosome
pairs line up randomly at the metaphase plate. This means the inheritance of an allele for
one trait (e.g., hair color) does not affect the inheritance of an allele for another trait (e.g.,
height), provided the genes are on different chromosomes.
Question 7
Albinism is a condition where a person lacks melanin pigmentation. If two parents with normal
pigmentation have a child with albinism, what does this suggest about the albinism trait?
A) It is a dominant trait.
B) It is a recessive trait.
C) It is a spontaneous mutation that only happens in males.
D) It is caused by an extra chromosome.
E) It is an environmental condition caused by diet.
, 4
Correct Answer: B) recessive
Rationale: If a trait appears in a child but is not present in either parent, the parents must
be "carriers" (heterozygous). This is the definition of an autosomal recessive inheritance
pattern, where the dominant "normal" allele masks the recessive "albino" allele in the
parents.
Question 8
In the study of cystic fibrosis (CF), researchers have found that the severity of the disease is
influenced by "modifier genes." Which body system has been found to harbor the most genes
influencing CF severity?
A) The skeletal system
B) The nervous system
C) The immune system
D) The muscular system
E) The integumentary system
Correct Answer: C) immune system
Rationale: While CF primarily affects mucus production in the lungs and digestive tract, the
body's response to the resulting chronic infections is mediated by the immune system.
Genetic variations in how the immune system handles inflammation and bacteria
significantly dictate how severe the lung damage will be for a specific patient.
Question 9
A normal gene encodes a protein of 350 amino acids. A mutation occurs that creates a "stop"
codon early, resulting in a protein with only the first 120 amino acids. What is the likely fate of
this mutant allele's product?
A) The protein may fail to fold correctly.
B) The protein may be degraded by the cell.
C) The protein will be unable to perform its original function.
D) The truncated protein may be shorter than the original.
E) All of these
