The temperature of the body is regulated almost entirely by nervous feedback mechanisms, and almost all these mechanisms operate through temperature regulating centers located in the hypothalamus. Following statements are as follows:

A. The anterior hypothalamic-preoptic area contains large numbers of heat-sensitive neurons, as well as about one third as many cold-sensitive neurons. These neurons are believed to function as temperature sensors for controlling body temperature.

B. The heat-sensitive neurons increase their firing rate 2- to 10-fold in response to a 10°C increase in body temperature. 

C. The cold-sensitive neurons, by contrast, increase their firing rate when the body temperature increases.

D. Anterior hypothalamus integrates the central and peripheral temperature sensory signals.

Which of the following combination is correct?

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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: 13162

#Unit 4. Cell Communication and Cell Signaling

In the amoeba Dictyostelium discoideum, cAMP acts as an extracellular signalling molecule and binds to and signals via a G protein–coupled receptor; it is not a second messenger. Amoeba cells were transfected with genes encoding two fusion proteins: a Gα fused to cyan fluorescent protein (CFP), and a Gβ fused to yellow fluorescent protein (YFP). CFP normally fluoresces 490-nm light; YFP, 527-nm light. In which conditions fluorescence

energy transfer occur from CFP to YFP?

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#Question id: 13163

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to the interaction between β2-adrenergic receptor and G- protein.

TLS Online TPP Program

#Question id: 13164

#Unit 4. Cell Communication and Cell Signaling

Match the following.

Column I	Column II	Column III
A. G Protein–Coupled Receptors That Activate PDE	i. cAMP	a. Increase in conversion of glycogen to glucose
B. G Protein–Coupled Receptors That Activate Adenylyl Cyclase	ii. cGMP	b. Hyperpolarization or depolarization of photoreceptor membrane
C. G Protein–Coupled Receptors That inhibit Adenylyl Cyclase	iii. DAG	c. activates genes necessary for cell division
D. G Protein–Coupled Receptors That Trigger Elevations in Cytosolic and Mitochondrial Calcium		d. increase in K+ permeability hyperpolarizes the membrane

Which one of the following is correct?

TLS Online TPP Program

#Question id: 13165

#Unit 5. Developmental Biology

One of the main ways by which the insulin signaling pathway might function to lower longevity is to activate mTORC1, a protein kinase complex that promotes the translation of mRNA into proteins in response to nutrients and hormones, select incorrect statement;

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#Question id: 13168

#Unit 10. Ecological Principles

Use the following diagram from the text showing the spread of the cattle egret, Bulbulcus ibis, since its arrival in the New World, to answer the following question.

How would an ecologist likely explain the expansion of the cattle egret?