The function of light is to excite a specialized chlorophyll in the reaction centre either by Direct absorption or more frequently, via energy transfer from an antenna pigment, This excitation process can be envisioned as

a.) An electron from the lowest-energy filled orbital of the chlorophyll to the highest-energy unfilled orbital

b.) An electron in the upper orbital is only tightly bound to the chlorophyll and is difficult to fetch the electron nearby molecules

c.)  The electron in the upper orbital is only loosely bound to the chlorophyll and is easily lost if a molecule that can accept the electron is nearby

d.) The promotion of an electron from the highest-energy filled orbital of the chlorophyll to the lowest-energy unfilled orbital

Which combination is CORRECT?

#Question id: 1399

#Unit 4. Cell Communication and Cell Signaling

Loss-of-function mutations in which of the following genes typifies colorectal carcinomas?

a. myc              b. K-ras                       c. p53              d. APC

#Question id: 1400

#Unit 4. Cell Communication and Cell Signaling

Which property is shared by malignant tumor cells and transformed cells in culture?

a. reduced growth factor requirement                        b. attachment-dependent growth

c. loss of actin microfilaments                                    d. altered morphology

#Question id: 1401

#Unit 4. Cell Communication and Cell Signaling

Which of the following are proto-oncogenes?

a. fos               b. myc             c. p53              d. ras               e. Rb

#Question id: 1402

#Unit 4. Cell Communication and Cell Signaling

Which of the following oncoproteins possess(es) protein kinase activity?

#Question id: 1403

#Unit 4. Cell Communication and Cell Signaling

Tumor-suppressor genes encode proteins with which of the following functions?

a. growth-promoting               b. growth-arresting                  c. pro-apoptotic

d. anti-apoptotic                      e. DNA repair

#Question id: 1404

#Unit 4. Cell Communication and Cell Signaling

Which of the following are transcription factors?