Cell Cycle Flashcards
What is the cell cycle
The cell cycle is the series of events that take place in a cell, eventually
leading to cell division
What is cell division
Cell division (mitosis) is the process by which two identical daughter
cells are made from one parent cell
What is interphase
Made up of the following stages:
- G1 (cell growth)
- S (DNA replication)
- G2 (preparation for mitosis)
What is the G1 Cell Growth phase
G1 phase: cells carry out their normal functions and grow in size. As
they get bigger, they produce extra copies of organelles
What is synthesis
Synthesis (S) phase: DNA replication occurs. All genetic material is
doubled inside the cell
Each chromosome replicates to form two sister chromatids held at a
centromere
What is the G2 Phase
G2 phase: cell continues to grow and checks DNA for errors. Ribosomes
will start to produce important proteins required for cell division
What is the G0 Phase
Some cells go to the G0 phase instead of G1. This is a resting phase
that the cell enters when there are unfavourable conditions, and the cell
cannot divide
- G0 phase: the cell performs maintenance and its other functions
What is the Mitotic M Phase
Made up of the following stages:
- Mitosis
- Cytokinesis
What is Mitosis
- Mitosis: the process in which a parent cell divides into two daughter
cells. It occurs in somatic/body cells as part of the cell cycle. The
daughter cells are identical to the parent cell. Cells divide for growth
and repair as well as to maintain large surface area to volume ratio - Cell division increases the efficiency of transport of materials into and
out of the cell by increasing the SA:V ratio
What happens during Mitosis
- During mitosis, the two
replicated DNA copies are
separated, and the cell is
split into two during
cytokinesis, where the
cytoplasm is divided into
two new daughter cells
How does repair work
Living tissue is repaired by replacing
damaged or destroyed cells with identical,
new cells that perform the same function
(ex. broken bones, cuts in the skin, growing
new hair)
What are the four stages of mitosis
Mitosis occurs in 4 stages (PMAT):
- Prophase
- Metaphase
- Anaphase
- Telophase
What is prophase
DNA condenses into a very tight form called
chromosomes (it has already been replicated
during interphase)
- Each chromosome has two identical copies of
the same DNA - Nuclear membrane begins to dissolve
What is metaphase
Nuclear membrane is completely
dissolved
- Chromosomes line up at the middle of
the cell (cell equator) - Network of fibers called microtubules
forms, which helps in equally
distributing the DNA between the two
new cells
What happens in anaphase
Chromosomes get pulled
apart by the network of
microtubules, and move
towards opposite ends of the
cell
