Cell Division I: The Cell Cycle

Binary fission refers to the process by which

• a.the nucleus of a cell splits just prior to cytokinesis.
• b.most plant and animal cells reproduce.
• c.bacteria and other cells lacking a nucleus reproduce.
• d.a cell duplicates its DNA.

After a single cell divides, there are three cells -- the parent cell and two daughter cells.

• a.true
• b.false

The cell cycle can be described as

• a.chaotic and composed of various phases that are virtually indistinguishable when viewed through a microscope.
• b.identical in every kind of cell.
• c.a sequence of events that continues constantly in all cells.
• d.a pattern of distinct phases in a cell regulated by proteins.

The cell cycle can be reversed, causing a cell to move backward from mitosis, back to the G₂ and S-phases.

• a.true
• b.false

Arthur Pardee was looking for a "point of no return" in his experiments – a point in the life cycle where a cell commits to a path toward division or toward pausing in a quiescent state. Today, we call this point

• a.the restriction point.
• b.CDKs.
• c.mitosis.
• d.chroma.

Interphase collectively refers to

• a.mitosis and cytokinesis.
• b.G₀ and the restriction point.
• c.G₁, S-phase, and G₂.
• d.DNA synthesis and G₀.

Mitosis is a type of cell division.

• a.true
• b.false

Tim Hunt used radioactive tags in his experiments with sea urchin eggs so that he could observe

• a.how long it took for the cell cycle to restart after interruption.
• b.when new proteins were made during the process of cell division.
• c.if the cell cycle was reversible.
• d.how restriction works in a cell.

The cell cycle kinases are enzymes that are activated when __________ build up in the cytoplasm.

• a.cyclins
• b.DNA strands
• c.chroma
• d.bacteria

All cells that make up mammalian tissues continue to divide at a constant rate until cellular death.

• a.true
• b.false