Chapter 14 - New Body Cells Flashcards
What is mitosis?
The division of cells for growth and maintenance.
What are the six main phases of mitosis?
Interphase Prophase Metaphase Anaphase Telophase Cytokinesis
What occurs in interphase?
DNA molecules duplicate.
What occurs in prophase?
- nucleoli disappear
- nuclear membrane breaks down
- centrioles move to opposite poles
- chromosomes appear as pairs of chromatids
- spindle forms
What occurs in metaphase?
Chromosomes line up on the spindle in the centre of the cell.
What occurs in anaphase?
- centromeres divide
- chromosomes move to opposite ends of the cell
What occurs in telophase?
- spindle disappears
- nuclear membranes and nucleoli form
- centrioles divide
- chromosomes uncoil and disappear
- cytokinesis begins
What occurs in cytokinesis?
- cytoplasm of the cell divided into two, each with a nucleus
What is differentiation?
The process by which cells become specialised.
What are stem cells?
Cells that are not specialised for any particular role but undergo differentiation.
What does cancer result from?
The normal differentiation of a cell going wrong.
What are some examples of carcinogens?
- UV radiation
- x-rays
- ionising radiation
- viruses
- chemical carcinogens
What are the 4 phases of the cell cycle?
- G1 phase
- S phase
- G2 phase
- M phase
What is G0 phase of the cell cycle?
When a cell stops dividing for a period of time or for the person’s life
What occurs in G1 phase?
The cell:
- produces proteins
- grows
- carries out its normal tasks for the body
