Question 1

Proteins that are involved in developmental regulation are also commonly involved in what phenotype?&#10;A) Deafness&#10;B) Cancer&#10;C) Ataxia&#10;D) Neurodegeneration&#10;E) Premature aging

Accepted Answer

Proteins involved in developmental regulation often control cell growth, division, and differentiation, which are also critical processes in cancer development. Mutations in these proteins can lead to uncontrolled cell growth and contribute to the development of cancer.

Question 2

Which of the following types of developmental disorders are associated with mutations in the fibroblast growth factor receptor family?&#10;A) Congenital heart defects&#10;B) Holoprosencephaly&#10;C) Achondroplasias&#10;D) Defects in ocular development&#10;E) Defects in pigmentation

Accepted Answer

Achondroplasias are a group of skeletal dysplasias characterized by short stature and limb abnormalities, which are associated with mutations in the fibroblast growth factor receptor 3 (FGFR3) gene.

Question 3

How many Barr bodies does somebody with a 47,XXY karyotype have?&#10;A) 0&#10;B) 1&#10;C) 2&#10;D) 3&#10;E) More information is needed

Accepted Answer

A person with a 47,XXY karyotype has one Barr body. This is because the extra X chromosome is inactivated and forms a Barr body, while the Y chromosome does not form a Barr body.

Question 4

Which of the following chromosomal constitutions would be associated with a male phenotype?&#10;A) 45,X&#10;B) 47,XXY&#10;C) 47,XYY&#10;D) A and B&#10;E) B and C

Accepted Answer

B) 47,XXY and C) 47,XYY are both associated with a male phenotype. 47,XXY is known as Klinefelter syndrome, and individuals with this syndrome are male. 47,XYY is another variation that results in a male phenotype. 45,X, known as Turner syndrome, results in a female phenotype.

Question 5

Proteins that contain a zinc finger motif share what function?&#10;A) Kinase&#10;B) Phosphatase&#10;C) Protease&#10;D) Transcription factor&#10;E) Inducers of apoptosis

Accepted Answer

Proteins that contain a zinc finger motif function as transcription factors.

Question 6

Which of the following are true of DNA methylation during reproduction?&#10;A) The sperm and egg DNA maintain their methylation patterns throughout gametogenesis&#10;B) The sperm and egg DNA maintain their methylation patterns in the embryo&#10;C) Methylation patterns in both the egg and sperm DNA are erased at fertilization and re-established in a single wave&#10;D) Only the sperm DNA loses its methylation pattern after fertilization&#10;E) A series of methylation and demethylation events occurs during gametogenesis, fertilization, and implantation in both gametes

Accepted Answer

During reproduction, DNA methylation patterns undergo a series of changes, including demethylation and remethylation, in both gametes during gametogenesis, fertilization, and implantation.

Question 7

What is an additional concern with complete hydatidiform moles that is not associated with partial moles?&#10;A) Risk of severe developmental issues in the fetus&#10;B) Malignancy&#10;C) Loss of fertility&#10;D) Imprinting defects&#10;E) Later endometriosis

Accepted Answer

Complete hydatidiform moles have a greater risk of developing into malignancy compared to partial moles.

Answer: D
 Complete hydatidiform moles have a higher risk of imprinting defects which can lead to overgrowth disorders or malignancy.

Question 8

An infertile female is found to have a 46,XY karyotype.Within which region is she likely to have a mutation or deletion?&#10;A) Pseudoautosomal region&#10;B) SRY&#10;C) XIST&#10;D) One of the AZF regions&#10;E) DAZ

Accepted Answer

The SRY gene, located on the Y chromosome, is responsible for the development of male gonads. Its presence is necessary for testis development and subsequently, male fertility. Thus, a female with a 46,XY karyotype is likely to have a mutation or deletion in the SRY region.

Question 9

Which of the following is a phenotype associated with mutations in the sonic hedgehog signaling pathway?&#10;A) Holoprosencephaly&#10;B) Osteogenesis imperfecta&#10;C) Primary sex reversal&#10;D) Spina bifida&#10;E) All of the above

Accepted Answer

Mutations in the sonic hedgehog signaling pathway are primarily associated with holoprosencephaly, which is a malformation of the brain and face. The other options listed are not typically associated with mutations in this pathway.

Deck 6: Developmental Genetics