2.1.6 (a, b) Cell cycle & checkpoints

The cell spends most of its time in which phase of the cell cycle?

(a)  

In what phase of the cell cycle does DNA replication occur?

• G1

• S

• G2

• mitosis

In what phase of interphase does a cell produce a supply of organelles for its daughter cells?

• G1

• S

• G2

In what cell cycle phase does the cell assemble structures like spindle fibres needed for mitosis?

• G1

• S

• G2

Why do cells undergo mitosis?

• growth
• repair of damaged cells
• replacement of dying cells.
• All of the above

What part of the cell cycle results in splitting into two new daughter cells?

• Interphase
• Mitosis
• Metaphase
• Cytokinesis

Checking for mutations in DNA occurs during which checkpoint? 

• G1

• G2

• S

What could be a consequence of mutation in a gene coding for a checkpoint protein? 

(a)  

Suggest why cancer medicines make your hair fall out?

Answer explanation

Hair is continuously growing, so hair root cells are continually dividing (undergoing mitosis). Cancer medicines target cells that are rapidly dividing, so can target those cells too.