You are interested in a new type of autosomal dominant mutation that gives purple eyes in Drosophila. You have a true-breeding purple-eyed line carrying a mutation that you call pr-1. You have isolated a second purple-eyed mutation that you call pr-2, which you have established in a true-breeding line that also carries a recessive marker st, which gives stubby legs. You cross a fly from the pr-1 line to a fly from the st, pr-2 line producing F1 females which you then cross to males from a true breeding st line (normal eyes). From this cross, 1000 progeny flies can be categorized into four different phenotypic classes:

                   

What is the phenotype of a pr-1 pr-2 double mutant?

#Question id: 1134

#Unit 4. Cell Communication and Cell Signaling

Arrange the following proteins in the proper order in which they become activated in the MAPK signaling pathway:

a. MAP kinase                         b. MEK           c. Ras              d. Raf              e. RTK            

#Question id: 1135

#Unit 4. Cell Communication and Cell Signaling

Which of the following is a direct substrate of MAP kinase?

a. TCF             b. SRF             c. SRE             d. p90RSK      e. CREB

#Question id: 1136

#Unit 4. Cell Communication and Cell Signaling

Which of the following signaling pathways can be activated by activation of receptor tyrosine kinases?

a. phospholipase Cγ                b. PI-3 kinase

c. MAP kinase                         d. none of the above

#Question id: 1137

#Unit 4. Cell Communication and Cell Signaling

A loss-of-function mutation in PTEN phosphatase results in

a. increased cell proliferation.            

b. decreased cell proliferation.

c. increased apoptosis.                                   

d. decreased apoptosis.

#Question id: 1138

#Unit 4. Cell Communication and Cell Signaling

A loss-of-function mutation in Wnt would have a phenotype similar to a

a. gain-of-function mutation in GSK-3.                    

b. gain-of-function mutation in β-catenin.

c. loss-of-function mutation in GSK-3.                     

d. loss-of-function mutation in β-catenin.

#Question id: 1139

#Unit 4. Cell Communication and Cell Signaling

In paracrine signaling, the signaling molecule: