mitosis 23
Post on 03-Apr-2018
215 Views
Preview:
TRANSCRIPT
-
7/28/2019 Mitosis 23
1/2
Jenny Truong
Biology: Mitosis Review
1
Review
1. What is cell division?A multicellular organism such as a human begins life as a single cell formed from the union of two sex cells. From this
microscopic beginning the organism grows to become an adult.
This is achieved by the process of cell division. One cell divides forming two cells and then each of these cells divideforming more cells to continue the process of cell division.
2. Where does it occur?The cell division occurs in the nucleus
Mitosis Review
1. What is Mitosis?Mitosis is a type of cell division that results in the replication of identical cells. Meiosis is another type of cell division
which produces gametes or sex cells. Meiosis produces cells that have half the number of chromosomes of the
parent cell.
Mitosis is the process that is made up in two parts:
- Mitosis is the process where the nucleus divides into two separate nuclei- [Refer back to Question 4]
2. How does it work?The role of mitosis in multicellular organisms can be summarised 4 sub-subjects:
1. GROWTH2. REPAIR of the damaged tissue and replacement of worn out cells3. GENETIC STABILITY: mitosis ensures the precise and equal distribution of chromosomes of each daughter nucleus,
so that all resulting cells contain the same number and kind of chromosomes as each other and as the original
parent cell
4. ASEXUAL REPRODUCTION + CLONING: An artificially-induced form of asexual reproduction in multicellularorganisms that relies on human intervention and genetic modification
- It also provides reproduction for unicellular organisms3. How does it fit in the cell cycle?
Cell division and enlargement occur in a repetitive sequence called the cell cycle, with one complete the cell cycle
taking about 18-22 hours in many species.
Mitosis is only one part of the cell cycle and is usually takes 1-2 hours.
Before a cell divides, it undergoes preparation for division and this preparation phase, called INTERPHASE takes
longer (longest phase in mitosis)
- Interphase is subdivided into 3 stages: G1, S and G24. What is Cytokinesis?
Mitosis refers to the changes involving the chromosomes during cell division. Cell division, however, usually includes
the division of the cytoplasm and certain organelles within the cytoplasm. The division of the cytoplasm is called
cytokinesis.
- Cytokinesis is the division of the cytoplasm forming two new cells5 stages of Mitosis: IPMAT, 4 MOST IMPORTANT IS PMAT
INTERPHASE: The cell is not dividing, but chromosomes are duplicating. Chromosomes are not visible PROPHASE: The chromosomes condense and become visible as 2 joined strands, called chromatids, joined at
the centromere. The nuclear membrane breaks down
METAPHASE: The chromosomes line up at the centre of the cell, by a SPINDLE (system of micro tubes). Thechromatid separate
ANAPHASE: The single stranded chromosomes move to the opposite poles of the cell TELOPHASE: Spindle disappears. Two new nuclear membranes appear
-
7/28/2019 Mitosis 23
2/2
Jenny Truong
Biology: Mitosis Review
2
top related