Genetics NURS 6233 – FINAL Exam
with All Correct Answers 2025\2026
Version.
Alkaptonuria, symptoms - Answer Results in abnormal pigmentation and debilitating arthritis
due to a loss-of-function mutation
Alkaptonuria caused by - Answer homogentisic acid (HGA) which is an intermediate
metabolite in phenylalanine and tyrosine metabolism is found in large quantities in urine which
turns urine black in the presence of light Oxidation product of HGA is directly deposited in
connective tissues
Trisomy 13 (Patau Syndrome) mechanism - Answer An error in cell division called
nondisjunction results in a reproductive cell with an abnormal number of chromosomes. More
rarely Translocation trisomy 13 can be inherited.
Trisomy 13 - Answer Patau syndrome
Edwards Syndrome mechanism - Answer (nondisjunction). partial trisomy 18 can be inherited
(translocation)
Down Syndrome mechanism - Answer is caused by a failure of the 21st chromosome to
separate during egg or sperm development (nondisjunction)
Trisomy 18 - Answer Edwards syndrome
Trisomy 21 - Answer Downs Syndrome
Patau syndrome - Answer Females more frequently. Children who survive infancy have
significant Developmental disability, polydactyl , renal abnormalities Orofacial clefts,
microphthalmia (small, abnormally formed eyes), postaxial polydactyly, heart and renal
abnormalities, cutis aplasia (a defect of the skin of the scalp on the posterior occiput)
Edwards syndrome - Answer Prenatal growth deficiency; short palpebral fissures and ear
variations; overriding of index finger onto the third finger Congenital heart defects (VSDs); most
, Down syndrome - Answer depressed nasal root, upslanting palpebral fissures, overfolded ears,
flattened maxillary and malar region short neck; single flexion crease across their palms;
decreased muscle tone 40% have structural heart defects (AV canal (interatrial and
interventricular L-R shunt and pulmonary htn; VSD are also common
Chromosomal mechanisms involved in the development of Down Syndrome - Answer An error
in cell division called nondisjunction results in a reproductive cell with an abnormal number of
chromosomes. The egg of the sperm gain an extra copy of the chromosome. Translocation a
break in a chromosome and that part will fuse with a different chromosome.
Genetic disorders that could have mosaicism - Answer Klienfelters syndrome, down syndrome,
and turner syndrome
What is mosaicism and how does it occur? - Answer is when a person has 2 or more
genetically different sets of cells in his or her body. Caused by an error in cell division early in
development.
Chomosomal nomenclature - Answer the total # of chromosomes separated by a comma and
then the sex chrmosomes Normal male (46,XY) Normal female (46,XX)
Aneuploidy - Answer cells that contain missing or additional individual chromosomes (not a
multiple of 23 chromosomes) Most common cause of is nondisjunction (failure of chromosomes
to disjoin normally during meiosis (can occur in meiosis 1 or 2) Resulting gamete either lacks a
chromosome or has 2 copies of it; producing a monosomic or trisomic zygote
Euploid - Answer A cell that contains a multiple of 23 chromosomes in its nucleus ("good set"
Diploid - Answer A cell containing two complete sets of chromosomes, one from each parent
Haploid - Answer cell having single set of chromosomes gametes in humans
Polyploidy - Answer presence of a complete set of extra chromosomes in a cell (triploidy = 69
chromosomes and tetraploidy 92 chromosomes in each cell)
Nomenclature for chromosomes (arms) - Answer Short arm of chromosome= p Long arm = q
with All Correct Answers 2025\2026
Version.
Alkaptonuria, symptoms - Answer Results in abnormal pigmentation and debilitating arthritis
due to a loss-of-function mutation
Alkaptonuria caused by - Answer homogentisic acid (HGA) which is an intermediate
metabolite in phenylalanine and tyrosine metabolism is found in large quantities in urine which
turns urine black in the presence of light Oxidation product of HGA is directly deposited in
connective tissues
Trisomy 13 (Patau Syndrome) mechanism - Answer An error in cell division called
nondisjunction results in a reproductive cell with an abnormal number of chromosomes. More
rarely Translocation trisomy 13 can be inherited.
Trisomy 13 - Answer Patau syndrome
Edwards Syndrome mechanism - Answer (nondisjunction). partial trisomy 18 can be inherited
(translocation)
Down Syndrome mechanism - Answer is caused by a failure of the 21st chromosome to
separate during egg or sperm development (nondisjunction)
Trisomy 18 - Answer Edwards syndrome
Trisomy 21 - Answer Downs Syndrome
Patau syndrome - Answer Females more frequently. Children who survive infancy have
significant Developmental disability, polydactyl , renal abnormalities Orofacial clefts,
microphthalmia (small, abnormally formed eyes), postaxial polydactyly, heart and renal
abnormalities, cutis aplasia (a defect of the skin of the scalp on the posterior occiput)
Edwards syndrome - Answer Prenatal growth deficiency; short palpebral fissures and ear
variations; overriding of index finger onto the third finger Congenital heart defects (VSDs); most
, Down syndrome - Answer depressed nasal root, upslanting palpebral fissures, overfolded ears,
flattened maxillary and malar region short neck; single flexion crease across their palms;
decreased muscle tone 40% have structural heart defects (AV canal (interatrial and
interventricular L-R shunt and pulmonary htn; VSD are also common
Chromosomal mechanisms involved in the development of Down Syndrome - Answer An error
in cell division called nondisjunction results in a reproductive cell with an abnormal number of
chromosomes. The egg of the sperm gain an extra copy of the chromosome. Translocation a
break in a chromosome and that part will fuse with a different chromosome.
Genetic disorders that could have mosaicism - Answer Klienfelters syndrome, down syndrome,
and turner syndrome
What is mosaicism and how does it occur? - Answer is when a person has 2 or more
genetically different sets of cells in his or her body. Caused by an error in cell division early in
development.
Chomosomal nomenclature - Answer the total # of chromosomes separated by a comma and
then the sex chrmosomes Normal male (46,XY) Normal female (46,XX)
Aneuploidy - Answer cells that contain missing or additional individual chromosomes (not a
multiple of 23 chromosomes) Most common cause of is nondisjunction (failure of chromosomes
to disjoin normally during meiosis (can occur in meiosis 1 or 2) Resulting gamete either lacks a
chromosome or has 2 copies of it; producing a monosomic or trisomic zygote
Euploid - Answer A cell that contains a multiple of 23 chromosomes in its nucleus ("good set"
Diploid - Answer A cell containing two complete sets of chromosomes, one from each parent
Haploid - Answer cell having single set of chromosomes gametes in humans
Polyploidy - Answer presence of a complete set of extra chromosomes in a cell (triploidy = 69
chromosomes and tetraploidy 92 chromosomes in each cell)
Nomenclature for chromosomes (arms) - Answer Short arm of chromosome= p Long arm = q
