In Neurospora a cross between the genotypes 'A' and 'a' results in an ascus with ascospores of genotypes as shown below: 

Ascus Class	Ascospore
I	A	A	A	A	a	a	a	a
II	A	A	a	a	a	a	A	A

 Statements A to D are events that could have occurred during meiosis.

A) Class I is results of no crossing over between the centromere and gene.

B) Class II is results of single crossing over between the centromere and gene

C) Class I shows segregation of alleles 'A' and 'a' in meiosis II

D) Class II shows segregation of alleles 'A' and 'a' in meiosis II

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#Question id: 13161

#Unit 4. Cell Communication and Cell Signaling

Which of the following mechanism depends on the activation of heterotrimeric G proteins?

TLS Online TPP Program

#Question id: 13160

#Unit 4. Cell Communication and Cell Signaling

According to the Switching mechanism, monomeric G proteins exist in two states. Match the following states (Column I) with correct mechanism (Column II).

Column I	Column II
A. “ON” state	i. switch I and switch II, are bound to the terminal γ phosphate of GTP through interactions with the backbone amide groups of conserved threonine and glycine residues.
B. “OFF” state	ii. GTPase-activating proteins
	iii. guanine nucleotide exchange factor
	iv. Due to the removal of the γ phosphate by GTPase-catalyzed hydrolysis causes switch I and switch II to relax into a different conformation

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#Question id: 13159

#Unit 4. Cell Communication and Cell Signaling

How signaling is involved in ensuring that yeast cells fuse only with cells of the opposite mating type?

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#Question id: 1262

#Unit 4. Cell Communication and Cell Signaling

Although MAP kinase is often activated in multicellular animals by RTKs or cytokine receptors, signaling from other receptors can activate MAP kinase in other eukaryotic cells. we consider the mating pathway in the yeast S. cerevisiae, a well-studied example of a MAP kinase cascade linked to G protein–coupled receptors (GPCRs). Which of the following statement is incorrect?

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#Question id: 1261

#Unit 4. Cell Communication and Cell Signaling

A FOXO3a mutant in which the three serine residues that are targets for PKB are mutated to alanine then what will be the result?

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#Question id: 1260

#Unit 4. Cell Communication and Cell Signaling

Which of the following statement regarding RTK/Ras pathway is incorrect?