#Question id: 1364
#Unit 4. Cell Communication and Cell Signaling
In mice engineered to overexpress the syndecan-1 gene in the hypothalamic region of the brain and other tissues, normal control of feeding by antisatiety peptides is disrupted, and the animals overeat and become obese. Other studies have shown that syndecan-3 may also be involved in the regulation of feeding behavior. Given the following information, which of these outcomes might you expect in experimentally manipulated mice?
I. Hypothalmic expression of syndecan-3 is increased by fasting.
II. Syndecan-3 knockout mice are resistant to diet-induced obesity.
III. Heparinase can cleave syndecan-3 to release heparin sulfate GAG chains that may suppress the activity of antisatiety peptides and feeding behavior.
Following statements are:
A. Overexpression of heparinase in mice with normal levels of syndecan-3 would result in resistance to diet-induced obesity.
B. In mice with normal levels of syndecan-3, fasting followed by free access to a high-fat diet would lead to resistance to diet-induced obesity.
C. Lack of heparinase in mice with normal levels of syndecan-3 would result in animals that overeat and become obese.
D. Overexpression of heparinase in syndecan-3 knockout mice would reverse the resistance to diet-induced obesity.
Which of the following combination is correct?
#Question id: 1316
#Unit 4. Cell Communication and Cell Signaling
Many second messengers (e.g., cyclic AMP, IP3, and Ca2+) can be transferred between cells through:
#Question id: 12677
#Unit 10. Ecological Principles
#Question id: 11261
#Unit 10. Ecological Principles
Which of the following kinds of social interactions cannot be favoured by natural selection under any circumstance?
#Question id: 10162
#Unit 6. System Physiology – Plant
Following are certain statements regarding C3, C4 and CAM plants
a.) The atmospheric CO2 assimilates into the single cell C4 cycle diatoms, C4 conc. Is higher at the external side where the C3 conc. Is higher at the internal side where the CO2 assimilation takes place and the transport to the vascular tissue
b.) In mitochondria, two molecules of glycine yield a molecule of serine with the concurrent release of CO2 and NH4+ by the successive action of the glycine decarboxylase complex Only
c.) Plant with the C4 metabolism need less rubisco than C3 plants to achieve a given rate of Photosynthesis
d.) CAM Plant PEP Case only active during the Dark due to its phosphorylation while C4 PEP Case active throughout the day
Which of the following combination from above statements are TRUE?