What quadrant is it in?  

A scientist is studying a mutant cell line that progresses through G1 phase but repeatedly fails to enter S phase, despite the presence of adequate nutrients and growth signals. She discovers that the mutant cells produce normal levels of cyclins but have severely reduced Cdk activity. Which of the following best explains why these cells cannot proceed to the next phase of the cell cycle?

Why does the loss of function in a tumor suppressor gene usually require mutations in both copies of the gene?  

Match the protein transport to the processes that utilize them:

Which of the following best describes the role of hematopoietic stem cells (HSCs) in blood cell development?  

A mutation causes the Gα subunit of the G protein to remain GTP-bound. Which of the following best describes the likely consequence?

Match the stage of M phase to their description

True or False: If a transporter protein uses ATP to move solutes against their gradient it is a passive transporter.

From the selections presented, what feature is shared by the left upper limb, left lower limb, right lower limb, and left side of the head and neck?

Which is not a location where lymph nodes are commonly found?