Interphase

Question 1

The most basic function of the cell cycle is ..

Answer 1

to duplicate accurately the vast amount of DNA in the chromosomes and then to segregate the DNA into genetically identical daughter cells such that each cell receives a complete copy of the entire genome

Question 2

In most cases, a cell also duplicates its other macromolecules and organelles and doubles in size before it divides; why

Answer 2

otherwise, each time a cell split it would get smaller and smaller

Question 3

Each daughter cell can divide again by

Answer 3

going through another cell cycle

Question 4

The duration of the cell cycle varies greatly from one cell type to another

Answer 4

True

Question 5

Interphase is the longest phase

Answer 5

True

Question 6

Interphase includes

Answer 6

S phase,g1,g2

Question 7

During these gap phases

Answer 7

the cell monitors both its internal state and external environment.

Question 8

Why

Answer 8

This monitoring ensures that conditions are suitable for reproduction and that preparations are complete before the cell commits to the major upheavals of S phase and mitosis

Question 9

The cell-cycle control system regulates progression through the cell cycle at three main transition points.

Answer 9

True

Question 10

At the transition from G1 to S phase

Answer 10

the control system confirms that the environment is favorable for proliferation before committing to DNA replication

Question 11

What is G0

Answer 11

Resting state

Question 12

At the transition from G2 to M phase

Answer 12

the control system confirms that the DNA is undamaged and fully replicated, ensuring that the cell does not enter mitosis unless it’s DNA is intact.

Question 13

during mitosis, the cell-cycle control machinery ensures that

Answer 13

the duplicated chromosomes are properly attached to a cytoskeletal machine, called the mitotic spindle, before the spindle pulls the chromosomes apart and segregates them into the two daughter cells

Question 14

The cell-cycle control system governs the cell-cycle machinery by cyclically activating and then inactivating the key proteins and protein complexes that initiate or regulate DNA replication, mitosis, and cytokinesis.

Answer 14

True

Question 15

This regulation is carried out largely through the ….. of proteins involved in these essential processes

Answer 15

phosphorylation and dephosphorylating

Question 16

The protein kinases at the core of the cell-cycle control system are present in proliferating cells throughout the cell cycle.

Answer 16

True

Question 17

Switching these kinases on and off at the appropriate times is partly the responsibility of

Answer 17

Cyclins proteins

Question 18

Cyclins have no enzymatic activity themselves, but they need to bind to the…. before the kinases can become enzymatically active.

Answer 18

cell-cycle kinases

Question 19

The kinases of the cell-cycle control system are therefore known as cyclin- dependent protein kinases, or Cdks.

Question 20

The cyclin that acts in G2 to trigger entry into M phase is called M cyclin, another cyclin S, help launch S phase late in G1.

Answer 20

True

Question 21

Each of these cyclin–Cdk complexes phosphorylates a different set of target proteins in the cell

Answer 21

True