In Drosophila melanogaster, vestigial wings are determined by a recessive allele of a gene that is linked to a gene with a recessive allele that determines black body color. T. H. Morgan crossed black-bodied, normal-winged females and gray-bodied, vestigial-winged males. The F1 were all gray bodied, normal winged. The F1 females were crossed to homozygous recessive males to produce testcross progeny. Morgan calculated the map distance to be 17 map units. Which of the following information is correct about the testcross progeny?

TLS Online TPP Program

#Question id: 1106

#Unit 4. Cell Communication and Cell Signaling

Protein kinase is an enzyme that functions in which of the following ways?

TLS Online TPP Program

#Question id: 1108

#Unit 4. Cell Communication and Cell Signaling

Which of the following amino acids are most frequently phosphorylated by protein kinases in the cytoplasm during signal transduction?

TLS Online TPP Program

#Question id: 1107

#Unit 4. Cell Communication and Cell Signaling

Viagra causes dilation of blood vessels and increased blood flow to the penis, facilitating erection. Viagra acts by inhibiting which of the following events?

TLS Online TPP Program

#Question id: 1109

#Unit 4. Cell Communication and Cell Signaling

What role do phosphatases play in signal transduction pathways?

TLS Online TPP Program

#Question id: 1110

#Unit 4. Cell Communication and Cell Signaling

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound that does which of the following?

TLS Online TPP Program

#Question id: 14740

#Unit 4. Cell Communication and Cell Signaling

Rod cells sense light with the aid of a light-sensitive GPCR known as rhodopsin; choose incorrect statements

a. Rhodopsin consists of the protein opsin, which has the usual seven–transmembrane segment GPCR structure, covalently linked to a light-absorbing pigment called retinal. 

b. Rhodopsin, found only in rod cells, is localized to the thousand or so flattened membrane disks that make up the inner segment of each of these rod-shaped cells.

c. A human rod cell contains about 4 × 10⁷ molecules of rhodopsin. 

d. The heterotrimeric G protein coupled to rhodopsin, called transducin (Gt), contains a Gα unit referred to as Gαt; like rhodopsin, Gαt is found only in rod cells.