Deck 14: Developmental Genetics and Birth Defects

Question 1

What term is used for a collection of abnormalities that are caused by a single causative agent in parallel?

A) Deformation
B) Disruption
C) Cluster
D) Syndrome
E) Sequence

Answer 1

Syndrome

Question 2

What is the downstream effect of exposure to a morphogen?

A) Abnormal development
B) Cellular mutations
C) Cancer
D) Cellular differentiation
E) Cellular arrest

Answer 2

Cellular differentiation

Question 3

Which of the following is a totipotent cell?

A) Bone marrow stem cell
B) Nerve in central nervous system
C) Epithelial cell
D) Embryonic stem cell
E) All of the above

Answer 3

Embryonic stem cell

Question 4

Given the fact that the genome in an individual is the same in every cell in the body, what determines the gene expression pattern for any type of differentiated cell?

A) Genomic rearrangements
B) Epigenetic changes
C) Mitochondrial genome
D) Teratogens
E) All of the above

Question 5

Which of the following is a natural example that proves there is early regulative development in humans?

A) Monozygotic twinning
B) There are a predictable number of cells at various time points in early development
C) Exposure to teratogens can lead to defects that are obvious in the fetus
D) The vast majority of humans are symmetrical in overall body structure
E) Amniotic bands can lead to fetal disruptions

Question 6

Which morphogen is primarily responsible for setting the anterior-posterior axis in the developing limb?

A) Tbx4
B) Hedgehog
C) Sonic hedgehog
D) Wnt7
E) GLI3

Question 7

Which of the following occurs as a result of defects in migration of cortical neurons during development?

A) Holoprosencephaly
B) Anencephaly
C) Microcephaly
D) Lissencephaly
E) Spina bifida

Question 8

During which stage in development is preimplantation diagnosis possible?

A) Prior to fertilization
B) Regulative development
C) Mosaic development
D) Specification
E) Differentiation

Question 9

In dysmorphology, a disruption is a type of variation that is characterized by which of the following?

A) Destruction or interruption of intrinsically normal tissue
B) An underlying genetic mechanism
C) An abnormal developmental process
D) High recurrence risk
E) Somatic mutation during development

Question 10

Which of the following results from defects in migration of neural crest cells?

A) Lissencephaly
B) Hirschsprung disease
C) Crohn disease
D) Miller-Dieker syndrome
E) Achondroplasia

Question 11

What cell type is the exception to the rule that the gene expression profile in a particular type of differentiated cell does not involve permanent changes to the DNA sequence?

A) Neuron
B) Erythrocyte
C) Lymphocyte precursors
D) Epithelial cell
E) Germ cell

Question 12

Which of the following is the major form of programmed cell death during development?

A) Necrosis
B) Apoptosis
C) Cytolysis
D) Complete transcriptional shutdown
E) Autophagy

Question 13

What is the mechanism by which developmental morphogens such as Sonic hedgehog control body patterning?

A) By directly inducing gene expression
B) By directly suppressing gene expression
C) Through concentration gradients
D) The order of expression of hedgehog genes relates to their position in the genome and determines body patterning
E) By degrading proteins that suppress transcription

Question 14

What term is used for a collection of abnormalities in which the causative agent affected a single organ system at one point in development, and this had subsequent pleiotropic secondary effects?

A) Deformation
B) Disruption
C) Cluster
D) Syndrome
E) Sequence

Question 15

Which of the following is a possible consequence of a defect in anterior-posterior patterning in the limb?

A) Shortened limb
B) Synpolydactyly
C) Waardenburg syndrome
D) Congenital segmental overgrowth
E) Arthrogryposis

Question 16

What do we call an environmental agent that causes abnormal development in a fetus or embryo?

A) Mutagen
B) Teratogen
C) Carcinogen
D) Fetotoxic agent
E) Morphogen

Question 17

To which of the following categories does polydactyly belong?

A) Malformation
B) Disruption
C) Deformation
D) Skeletal dysplasia
E) Sequence