#Question id: 1359
#Unit 4. Cell Communication and Cell Signaling
Cells of the heart must contract in synchrony to produce an effective heart beat. The electrical signal telling each cell to contract must reach every cell of the heart at the same time. What kind of cell-to-cell junctions would you expect to find in heart tissue?
#Question id: 1360
#Unit 4. Cell Communication and Cell Signaling
Plasmodesmata of plant cells have .........in common with gap junctions in animal cells, but have .......... that gap junctions lack.
#Question id: 1361
#Unit 4. Cell Communication and Cell Signaling
Fluorscein that is injected into one plant cell .......show up in adjacent cells; DNA injected into one plant cell......... Show up in adjacent cells.
#Question id: 1362
#Unit 4. Cell Communication and Cell Signaling
That cancer cells often lack the gap junctions common to non-malignant cells of the same type is evidence that
#Question id: 1363
#Unit 4. Cell Communication and Cell Signaling
Which of the following statements best describes the difference between low-affinity integrins and high-affinity integrins?
#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?