Stomata from intact, attached leaves of Arabidopsis illuminated with blue, red, and green light in a growth chamber, increases and decreases their aperture in response to light.

 

Find the CORRECT statements from the above graph.

i) Stomatal aperture increases when the green light is turned off, and close when the green light is turned on again

ii) Stomata from the phototropin-less double mutant phot1/phot2 respond to blue light and open further when green light is turned off

iii) stomata from the zeaxanthin less mutant npq1 do not respond to blue light and least effect to opening of the stomata further when green light is turned off

iv) the npq1 mutant and phot1/phot2 double mutant response indicate that the green reversal of the blue-light response requires zeaxanthin but also phototropin

#Question id: 1370

#Unit 4. Cell Communication and Cell Signaling

H. V. Wilson worked with sponges to gain some insight into exactly what was responsible for holding adjacent cells together. He exposed two species of differently pigmented sponges to a chemical that disrupted intercellular junctions, and the cells of the sponges dissociated. Wilson then mixed the cells of the two species and removed the chemical that caused the cells to dissociate. Wilson found that the sponges reassembled into two separate species. The cells from one species did not interact or form associations with the cells of the other species.

How do you explain the results of Wilson's experiments?

#Question id: 1369

#Unit 4. Cell Communication and Cell Signaling

The following statements are made with reference to characteristics of glycosaminoglycans and proteoglycans, which are major constituents of extracellular matrix. Which one of them is incorrect?

#Question id: 1368

#Unit 4. Cell Communication and Cell Signaling

The following statements are made with reference to the characteristic of proteoglycans (major constituents of ECM). Which one of them is incorrect?

#Question id: 1080

#Unit 4. Cell Communication and Cell Signaling

 In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?

#Question id: 1081

#Unit 4. Cell Communication and Cell Signaling

Which of the following is a type of local signaling in which a cell secretes a signal molecule that affects neighboring cells?

#Question id: 1082

#Unit 4. Cell Communication and Cell Signaling

Which of the following is a type of signaling in which a cells respond to substrate that they themselves release ?