CELL DIVISION Flashcards
Cell Theory
- All organisms are composed of one or more cells.
- The cell is the structural and functional unit of life.
- Cells can arise only by division from preexisting cells
The process by which a parent cell DIVIDES into two or more daughter cells.
Results in the FORMATION OF NEW CELL.
Cell Division
Cell division in non-sex cells or somatic cell is called
MITOSIS
cell division involving sex cells is called
meiosis
basic unit of hereditary; codes for a specific
trait
Gene
the total hereditary endowment of DNA of a cell or organism
Genome
all body cells except reproductive cells
Somatic cell
reproductive cells (sperm & eggs)
Gamete
elongated cellular structure composed of DNA and protein
Chromosome
cellular condition where each chromosome type is represented by TWO homologous chromosomes
Diploid (2n)
cellular condition where each chromosome type is represented by only ONE chromosome.
Haploid (n)
chromosome of the same size and shape which carry the SAME TYPE OF GENES
Homologous chromosome
● The FIRST PART of cell cycle
● It is longer than the M phase
● Considered a RESTING STAGE in cell division
Interphase (non-dividing stage)
● Cells continue to grow
● RNA and protein production
● Produces enough energy for the next steps of the cell cycle
G1 PHASE
● DNA replication
● This results in the formation of two identical copies of the chromosomes called sister chromatids.
● These sister chromatids are joined together by a single centromere.
● Centrosomes also get duplicated during this phase.
S PHASE
● Duplication of organelles
● Protein synthesis
● Preparation for cell division
G2 PHASE
● In this stage cell, ceases growth and protein
production instead, it is now focusing in cell division
● Can either be mitosis or meiosis
M PHASE
● is the process, in the cell cycle, by which a cell DUPLICATES into TWO GENETICALLY IDENTICAL daughter cells.
● it is the division of the SOMATIC (body) cells
● It is the process of forming identical daughter cells by replicating and dividing the original chromosomes.
Mitosis
Mitotic Phases
● Prophase
● Metaphase
● Anaphase
● Telophase
*Chromatic materials THICKEN AND SHORTEN into double stranded chromosomes with two chromatids joined by CENTROMERE.
*The centrioles divide and produce ASTERS (asters are formed only for animal cells)
Prophase
formed only for animal cells
asters
● The MITOTIC SPINDLE, composed of microtubules and proteins, forms in the cytoplasm.
prophase
*The double stranded chromosomes ALIGN themselves at the EQUATORIAL REGION.
Metaphase
*Centromere SEPERATES/SPLIT.
*Single stranded chromosomes migrate to the OPPOSITE POLES
Anaphase