Mitosis Flashcards
2 Types of cell involve in Mitosis and Meiosis
Somatic Cells
Sex Cells
-Refers to all body cells except sex cells
-Contains Diploid (2n)
-Undergo Mitosis
Somatic cells
-Refers to the gametes (sperm cell for male and egg cell for female)
-Contain haploid (N) number of chromosomes.
Undergo mitosis and meiosis
Sex cells
-Cyclical of growth and mitosis
-A 4 stage process consisting of G1 (Cap and growth), S (synthesis), G2 (Gap and growth) and cell division (Mitosis and cytokinesis)
Cell cycle
-The stage between cell division.
-Occupies about 90% of the total cell cycle.
-The nucleus is clearly visible with one or more distinct nucleoli
-The chromosomes appear as irregular (granular)
-The nucleolus and the nuclear envelope form are distinct and the chromosomes are in the form of thread like chromatin
Interphase
Interphase is divided into
G1 period
S period
G2 period
-Growth and doubling of organelles
-Represents the early growth phase of the cell.
-The cell grows in volume as it produces tRNA, mRNA, ribosomes, enzymes, and other cell components
G1 (First Gap phase)
Growth continues, but this phase also involves DNA replication
S phase
-Growth and preparation for mitosis
-Prepares the cell for division.
-It includes replication of the mitochondria and other organelles.
-Synthesis of microtubules and protein that will make up the mitotic spindle fibers.
-Chromosome condensation
G2(Second gap phase)
-Process of distributing genetic materials
-Named by Walther Flemming
-Produces two daughter cells with the same quantity and quality of chromosomes as the
parent cell
Also called duplication division
Refers to the division of the nucleus (karyokinesis).
Quickly followed by the division of the cytoplasm (cytokinesis)
Mitosis
Mitosis is named by?
Walther Flemming
Four phases of Mitosis
- Prophase
- Metaphase
- Anaphase
- telophase
Characteristic of mitosis
Mitosis produces two genetically identical daughter cells from a single parent cell.
The major purpose of mitosis is for growth and to replace worn-out cells.
Mitosis occurs only in somatic cells, which are all the cells in the body except for the reproductive cells.
There is no reduction in the number of chromosomes during mitosis.
the chromatin in the nucleus condenses into visible chromosomes, which become visible under a microscope.
The centrosomes, which are responsible for organizing the spindle fibers, move to opposite poles of the cell.
The nuclear envelope breaks down, allowing the spindle fibers to attach to the chromosomes.
Prophase
the chromosomes line up along the equator of the cell, called the metaphase plate.
The spindle fibers, which are attached to the centromeres of each chromosome, ensure that the chromosomes are properly aligned and can be separated correctly
Metaphase
During this stage, the sister chromatids of each replicated chromosome separate and are pulled towards opposite poles of the cell by the spindle fibers.
This results in the formation of two identical sets of chromosomes at opposite poles of the cell.
Anaphase
the chromosomes reach the opposite poles of the cell, and the nuclear envelope begins to reform around each set of chromosomes.
The chromosomes begin to uncoil and return to their normal, diffuse form. The spindle fibers disassemble, and the cell begins to prepare for cytokinesis
Telophase
is the process by which the cell divides into two daughter cells.
In animal cells, a contractile ring of actin and myosin filaments forms around the cell, contracting and pinching the cell membrane until the cell is divided into two separate cells.
In plant cells, a structure called the cell plate forms along the equator of the cell, eventually dividing the cell into two separate daughter cells.
Cytokinesis
Resting state
A cell is performing its function without actively preparing to divide
G0 PHASE
IMPORTANCE OF MITOSIS
GROWTH & DEVELOPMENT
REPAIR & MAINTENANCE
ASEXUAL REPRODUCTION
Mitosis is essential for the growth and development of multicellular organisms. It allows cells to divide and multiply, leading to the formation of tissues, organs, and organ systems.
GROWTH & DEVELOPMENT
When tissues are damaged, such as in the case of a cut or injury, mitosis allows for the replacement of the damaged cells with new, healthy cells.
REPAIR & MAINTENANCE
In some organisms, mitosis allows for the production of genetically identical daughter cells, ensuring that the offspring are identical to the parent cell.
ASEXUAL REPRODUCTION
How many chromosome in prophase?
46
How many chromosome in metaphase?
46
How many chromosome in Anaphase?
92
How many chromosome in Telophase?
92
How many chromosome in end of mitosis (separated cells)?
46
