Question 1

Which developmental signaling pathway is frequently mutated in patients with colon cancer?&#10;A) FGF&#10;B) WNT&#10;C) SHH&#10;D) BMP&#10;E) PDGF

Accepted Answer

The WNT signaling pathway is frequently mutated in patients with colon cancer, leading to the activation of oncogenes and the inactivation of tumor suppressor genes. This can result in uncontrolled cell proliferation and the formation of tumors.

Question 2

Which phase of embryogenesis is characterized by extensive cell rearrangements that result in formation of a multilayered embryo?&#10;A) Organogenesis&#10;B) Cleavage&#10;C) Oogenesis&#10;D) Spermatogenesis&#10;E) Fertilization&#10;F) Gastrulation

Accepted Answer

Gastrulation is the phase of embryogenesis that involves extensive cell rearrangements resulting in the formation of a multilayered embryo. During gastrulation, the blastula (a hollow ball of cells) is converted into a gastrula, which has three distinct germ layers (ectoderm, mesoderm, and endoderm). These germ layers will give rise to various tissues and organs in the developing embryo.

Question 3

The period of the fetus occurs during which weeks postfertilization?&#10;A) 1-4&#10;B) 1-8&#10;C) 1-12&#10;D) 5-38&#10;E) 9-38&#10;F) 13-38

Accepted Answer

The period of the fetus occurs from weeks 9-38 postfertilization. During this stage, the fetal organs continue to develop and grow, and the fetus takes on a more distinct human form. It is also during this period that the fetus becomes increasingly responsive to external stimuli such as sound and touch.

Question 4

A fetus is examined in utero by ultrasound,and a defect of its ventral body wall is noted.The location of the defect corresponds to which surface of the adult?&#10;A) Superior&#10;B) Anterior&#10;C) Medial&#10;D) Posterior&#10;E) Lateral&#10;F) Inferior

Accepted Answer

The ventral body wall refers to the front surface of the body, which is also known as the anterior surface. Therefore, the location of the defect noted during ultrasound corresponds to the anterior surface of the adult.

Question 5

A child exhibiting early symptoms of progeria undergoes genetic testing.A gene coding for which protein is likely to be mutated?&#10;A) Laminin&#10;B) Fibronectin&#10;C) Collagen&#10;D) Lamin-A&#10;E) Insulin

Accepted Answer

Progeria is a rare genetic disorder characterized by premature aging in children. It is caused by a mutation in the LMNA gene, which codes for lamin-A protein. Lamin-A is a component of the nuclear envelope and is responsible for maintaining the structural integrity of the nucleus. A mutation in this gene results in abnormal lamin-A protein production, which causes the characteristic symptoms of progeria.

Deck 1: Introduction