A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island, and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none of them resembles her. There are, instead, several species each of which eats only a certain type of food. None of the species can fly, for their flight wings are absent, and their balancing organs (i.e., halteres) are now used in courtship displays. The male members of each species bear modified halteres that are unique in appearance to their species. Females bear vestigial halteres. The ranges of all of the daughter species overlap.In each fly species, the entire body segment that gave rise to the original flight wings is missing. The mutation(s) that led to the flightless condition could have

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#Question id: 15363

#Unit 4. Cell Communication and Cell Signaling

Epithelial-to-mesenchymal transition (EMT) is thought to play a crucial role during the process of metastasis in some cancers, Snail and Twist are the two transcription factors, function as EXCEPT

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#Question id: 15362

#Unit 4. Cell Communication and Cell Signaling

Aflatoxin a fungal metabolite found in moldy grains, induces

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#Question id: 15361

#Unit 4. Cell Communication and Cell Signaling

The chemical benzo(a)pyrene, found in cigarette smoke as well as in coal tar, undergoes metabolic activation in the lungs to form a potent mutagen that mainly, causes conversion of guanine (G) to thymine (T) bases, a transversion mutation, When applied to cultured bronchial epithelial cells, activated benzo(a)pyrene induces many mutations, including inactivating mutations of the p53 gene, at codon number______

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#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

Gene	Inherited syndrome
i. TP53	Li-Fraumeni syndrome
ii. INK4a	Familial melanoma
iii. PTEN	Familial gastric cancer
iv. E-Cadherin	Cowden disease
v. VHL	von Hippel-Lindau syndrome

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#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;

Gene	Primary tumor	Proposed function
i) APC	Colorectal	Binds β-catenin acting as transcription factor
ii) BRCA1	Breast	DNA repair
iii) MSH2, MLH1	Melanoma, pancreatic	p16: Cdk inhibitor ARF: stabilizes p53
iv) E-Cadherin	Breast, colon	Cell adhesion molecule
v) INK4a	Colorectal	Mismatch repair
vi) NF1	Neurofibromas	Activates GTPase of Ras

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

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?