TLS Online TPP Program

#Question id: 7129


What is the developmental pathway by which the hematopoietic stem cell gives rise to a macrophage?

#Unit 5. Developmental Biology
  1. the hematopoietic stem cell divides, giving rise to a daughter cell that remains a stem cell and a daughter cell that differentiates directly into a macrophage.
  2. the hematopoietic stem cell can give rise to either a lymphoid progenitor or a myeloid progenitor; the myeloid progenitor differentiates directly into a macrophage.
  3. The hematopoietic stem cell can follow two paths, one called lymphoid and the other called myeloid, either of which can ultimately give rise to macrophages and other cell types such as osteoclasts and T cells.
  4. the hematopoietic stem cell must first generate a cell of the myeloid lineage (as opposed to the lymphoid lineage), then a granulocyte/macrophage progenitor, then a monocyte, and finally a macrophage.
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TLS Online TPP Program

#Question id: 1538

#Unit 4. Cell Communication and Cell Signaling

Many aspects of the biology of stem cells, including maintenance of pluripotency, self-renewal, and differentiation, are controlled by the phenomenon of RNA interference involving a variety of small molecules of RNA.

Match the following miRNA (Column I) with their target gene (Column II).

Column I

Column II

a. Let-7 miRNA

i. Bcl-2

b. miR-16

ii. PTEN phosphatase

c. miR-125a and miR-125b

iii. Myc

d. miR-21

iv. LIN28

TLS Online TPP Program

#Question id: 15303

#Unit 4. Cell Communication and Cell Signaling

Neurofibromatosis, a benign tumor of the sheath cells that surround nerves, is caused by
a.  Loss of both alleles of NF1
b.  Mutation in RAS GAP-type protein
c.  A single mutant NF1 allele
d.  Mutation in SRC protein

TLS Online TPP Program

#Question id: 15304

#Unit 4. Cell Communication and Cell Signaling

An activating mutation of one of the two alleles of a proto-oncogene converts it into an oncogene, This can occur by EXCEPT

TLS Online TPP Program

#Question id: 15305

#Unit 4. Cell Communication and Cell Signaling

The multi-hit model, which proposes that multiple mutations are needed to cause cancer, which of the following is incorrect regarding to this model?

TLS Online TPP Program

#Question id: 15306

#Unit 4. Cell Communication and Cell Signaling

The transformation of a normal cell to a cancer cell is accompanied  by the loss of function of one or more tumor‐suppressor genes. High‐throughput sequencing studies have identified hundreds of genes that are implicated as tumor suppressors in humans. Some of the better characterized genes;

GenePrimary tumorProposed function
i) APCColorectalBinds β-catenin acting as transcription factor
ii) BRCA1BreastDNA repair
iii) MSH2, MLH1Melanoma, pancreatic

p16: Cdk inhibitor


ARF: stabilizes p53

iv) E-CadherinBreast, colonCell adhesion molecule
v) INK4aColorectalMismatch repair
vi) NF1NeurofibromasActivates GTPase of Ras

Choose incorrect matching regarding tumor‐suppressor genes/primary tumor/proposed functions;

TLS Online TPP Program

#Question id: 15307

#Unit 4. Cell Communication and Cell Signaling

In attached table some Tumor‐Suppressor Genes are given with their inherited syndrome; select correctly matched genes with their causing syndrome

GeneInherited syndrome
i. TP53Li-Fraumeni syndrome
ii. INK4aFamilial melanoma
iii. PTENFamilial gastric cancer
iv. E-CadherinCowden disease
v. VHLvon Hippel-Lindau syndrome