Updated By SaraNextGen
On March 11, 2024, 11:35 AM
INTRODUCTION - Chapter 10 Cell Cycle & Cell Division class 11 ncert solutions Biology - SaraNextGen [2024]
Question 1:
What is the average cell cycle span for a mammalian cell?
Answer:
The average cell cycle span for a mammalian cell is approximately 24 hours.
Question 2:
Distinguish cytokinesis from karyokinesis.
Answer:
|
Cytokinesis |
Karyokinesis |
||
|
(i) |
Cytokinesis is the biological process involving the division of a cell’s cytoplasm during mitosis or meiosis. |
(i) |
Karyokinesis is the biological process involving the division of a cell’s nucleus during mitosis or meiosis. |
|
(ii) |
Stages such as prophase, metaphase, anaphase, and telophase are not present in cytokinesis. |
(ii) |
It is divided into four stages –prophase, metaphase, anaphase, and telophase |
Question 3:
Describe the events taking place during interphase.
Answer:
Interphase involves a series of changes that prepare a cell for division. It is the period during which the cell experiences growth and DNA replication in an orderly manner. Interphase is divided into three phases.
(i) G1 phase
(ii) S phase
(iii) G2 phase
G1 phase – It is the stage during which the cell grows and prepares its DNA for replication. In this phase, the cell is metabolically active.
S phase – It is the stage during which DNA synthesis occurs. In this phase, the amount of DNA (per cell) doubles, but the chromosome number remains the same.
G2 phase – In this phase, the cell continues to grow and prepares itself for division. The proteins and RNA required for mitosis are synthesised during this stage.
Question 4:
What is G0 (quiescent phase) of cell cycle?
Answer:
G0 or quiescent phase is the stage wherein cells remain metabolically active, but do not proliferate unless called to do so. Such cells are used for replacing the cells lost during injury.
Also Read : Page-No-172:-Chapter-10-Cell-Cycle-&-Cell-Division-class-11-ncert-solutions-Biology
