Human Genetics BIO 302 Exam 1 Questions With Complete
Solutions
5 Basic Patterns of Mendelian Inheritance Correct Answers 1.
Autosomal Recessive
2. Autosomal Dominant
3. X - linked Recessive
4. X - linked Dominant
5. Y - linked Inheritance
A child is born with a lethal dominant allele. This would seem
impossible since neither of the parents possess this allele. What
is a possible explanation? Correct Answers 1. The allele could
have a delayed onset
2. The child's allele is a spontaneous mutation, neither parent
had to deal with
3. The allele could have varying expressivity and not always be
lethal
A hetero X linked color blindness woman as a male child with
an unaffected partner. What is the probability their child will be
an unaffected carrier for colorblindness allele? Correct Answers
0% of child will be unaffected for the colorblindness allele
A man with an X linked dominant trait has two boys and two
girls with an unaffected women. Which of the following is true
about the phenotype of these children? Correct Answers All the
girls will be affected but none of the boys will be affected
ART / Assisted Reproductive Technologies? Correct Answers
1. Focuses on 3 areas: retrieval or donation of gametes,
fertilization, and implantation of an embryo.
, ART Methods Correct Answers 1. IUI (Intrauterine
Insemination) - sperm is injected in the uterus
2. IVF (In Vitro Fertilization) - egg and sperm fertilization in a
laboratory and then implanted in female
a) Variation of IVF called ICSI (Intracytoplasmic Sperm
Injection) - egg is collected and injected with selected single
sperm then embryo develops in an incubator; used for low sperm
count or motility problems
3. Preimplantation Genetic Diagnosis (PGD) - removing a cell
from a day 3 embryo for genetic testing, genetic disorder
removed from the embryo by stem cells.
Autosomal Dominant Characteristics Correct Answers 1.
Heterozygous have abnormal phenotype
2. Unaffected people have 2 recessive alleles and normal
phenotype
3. every affected individual has atleast 1 affected parent
4. affected hetero individual with an unaffected mate, child's risk
is 50%
5. 2 affected people (usually hetero) can have unaffected child
Examples: Marfan Syndrome - affects skeletal system and eyes,
people are tall, thin with long legs and arms, heart defects.
Polydactyly: extra fingers or toes
Autosomal Recessive Characteristics Correct Answers 1. Rare
Traits - most affected individuals have unaffected parents
2. All children of affected parents are affected
3. Heterozygous parents, child's risk is 25%
4. Can appear dominant in a pedigree if common in population
Example: Cystic Fibrosis - fatal, abnormal secretion of glands,
pancreas and lungs are affected.
Solutions
5 Basic Patterns of Mendelian Inheritance Correct Answers 1.
Autosomal Recessive
2. Autosomal Dominant
3. X - linked Recessive
4. X - linked Dominant
5. Y - linked Inheritance
A child is born with a lethal dominant allele. This would seem
impossible since neither of the parents possess this allele. What
is a possible explanation? Correct Answers 1. The allele could
have a delayed onset
2. The child's allele is a spontaneous mutation, neither parent
had to deal with
3. The allele could have varying expressivity and not always be
lethal
A hetero X linked color blindness woman as a male child with
an unaffected partner. What is the probability their child will be
an unaffected carrier for colorblindness allele? Correct Answers
0% of child will be unaffected for the colorblindness allele
A man with an X linked dominant trait has two boys and two
girls with an unaffected women. Which of the following is true
about the phenotype of these children? Correct Answers All the
girls will be affected but none of the boys will be affected
ART / Assisted Reproductive Technologies? Correct Answers
1. Focuses on 3 areas: retrieval or donation of gametes,
fertilization, and implantation of an embryo.
, ART Methods Correct Answers 1. IUI (Intrauterine
Insemination) - sperm is injected in the uterus
2. IVF (In Vitro Fertilization) - egg and sperm fertilization in a
laboratory and then implanted in female
a) Variation of IVF called ICSI (Intracytoplasmic Sperm
Injection) - egg is collected and injected with selected single
sperm then embryo develops in an incubator; used for low sperm
count or motility problems
3. Preimplantation Genetic Diagnosis (PGD) - removing a cell
from a day 3 embryo for genetic testing, genetic disorder
removed from the embryo by stem cells.
Autosomal Dominant Characteristics Correct Answers 1.
Heterozygous have abnormal phenotype
2. Unaffected people have 2 recessive alleles and normal
phenotype
3. every affected individual has atleast 1 affected parent
4. affected hetero individual with an unaffected mate, child's risk
is 50%
5. 2 affected people (usually hetero) can have unaffected child
Examples: Marfan Syndrome - affects skeletal system and eyes,
people are tall, thin with long legs and arms, heart defects.
Polydactyly: extra fingers or toes
Autosomal Recessive Characteristics Correct Answers 1. Rare
Traits - most affected individuals have unaffected parents
2. All children of affected parents are affected
3. Heterozygous parents, child's risk is 25%
4. Can appear dominant in a pedigree if common in population
Example: Cystic Fibrosis - fatal, abnormal secretion of glands,
pancreas and lungs are affected.
