Lesson 2 : Cell Division and Cell Death Flashcards
What is Cell Division
Reproduction of 2 daughter cells from a single parent cell.
What are Somatic Cells
- Non-sex cells that have 23 pairs of chromosomes in humans.
- 2 copies of genome.
What is Mitosis
- Provides new cells by forming the cells form one.
- They occur in somatic cells (body cells)
- From of 2 daughter cells from a single parent.
Series of events or a sequence of activities as the cell prepares for cell division and then divide
Cell Cycle
What is Aptosis
- Form of cell death which is normal in growth and development.
- Precise genetically sequence of events like mitosis.
- Death due to natural causes like underwent cell division and becoming worn out. happens also due to old age of the cell.
G1 (Growth 1)
- Growth stage of interphase
- Cells grow to its full size
- Performs many biochemical functions that aid the organism.
- First gap or first stage.
- Little change is visible.
- Cells are quite active at the biochemical level.
- Accumulating building blocks of chromosomal DNA and associated proteins, energy reserves to complete the task of replicating each chromosome in the nucleus.
What is Interphase
- Phase where in division has not yet occurred.
- Undergo normal processes while preparing for cell division.
- A phase where many internal and external conditions must be met.
G0 (Gap 0)
- Quiet stage
- Cell divides if it continues to synthesis or undergo cell death or cell differentiation.
- Not included in stages of interphase
the apparatus that orchestrate the movement of chromosomes during mitosis
Centrosome
S (Synthesis)
- Important because it is where nucleus replicates.
- DNA Replication results in formation of 2 identical copies of each Chromosome which we call sister chromatids.
these are firmly attached at the centromere region
Sister chromatids
Prometaphase
- Chromosomes continue to condense.
- Kinetochores appear at the centromeres.
- Mitotic spindle microtubules attached in kinetochores.
- Centrosomes move toward opposite poles.
Two centrosome will give rise to ____________
mitotic spindle
consist of rod-like centrioles at right angles to each other
Centrosome
Metaphase
- Aligning of chromosomes
- Lining up at the metaphase plate.
- Each sister chromatid attaches to the spindle fibers originating from opposite poles.
- Mitotic spindle is fully developed, centrosome poles move at opposite ends/poles ng cells
- Chromosomes are lined up at the metaphase plate
Prophase
- First stage of mitosis
- Nucleolus disappears
- Where chromatin will condense into chromosomes
- Centrioles will move to opposite ends.
- Nuclear membrane breakdown happens in Prometaphase.
- Spindle fibers emerge from the centrosomes.
G2 (Growth 2)
- Completed mitosis/ growth stage is completed.
- The cell replenishes its energy stores and synthesizes proteins necessary for chromosome manipulation.
- Some cell organelles are duplicated and cytoskeleton are dismantled to provide resources to mitotic spindle fibers.
- Final preparations before undergoing cell division.
Stages of Mitosis
Prophase, Metaphase, Anaphase, Telophase
help in cell division, but are not present in centrosomes of eukaryotic organisms such as plants and most fungi, but found in animals and humans
Centrioles
Anaphase
Chromosomes start to separate.binding sister
chromatids together breakdown.
Cohesin proteins
How many daughter cells does Meiosis have
4 daughter cells
Sister chromatids now called __________________ are pulled toward opposite poles.
chromosomes
Cytokinesis
- The organelles in the cell have been replicated and are now divided into 2 halves of the cell.
- The nuclear membrane is now fully developed.
Process where cell is compressed by a _________________ that divides the cell in nearly equally halves.
contractile rim
There will be a ____________ ___________ that separates the daughter cells.
cleavage furrow
Telophase
- Nuclear membrane starts to reappear.
- Cytoplasm divides to form 2 cells.
- They are now or already arriving at the opposite poles and they begin to decondense.
- Nuclear envelope material surrounds each set of chromosomes.
- Mitotic spindle fibers break down.
- The broken down nuclear membrane starts to reappear at telophase, but is not that prominent or fully developed.
sex cells; germline cells; haploid (1 copy of each type of chromosome)
Gametes
What is Meiosis
Cell division that halves the number of chromosomes to form haploid gametes.
Cell division I (Division Reduction)
Prophase I
Metaphase I
Anaphase I
- thickening of chromatin
- alignment of chromosomes
- chromosomes are reduced to 23
Cell division II
Prophase II
Metaphase II
Anaphase II
Telophase II
Result:
- each daughter cells have 23 chromosomes.
- alignment of chromosomes
- 46 chromosomes
- 23 chromosomes
- Haploid cells (4 daughter cells)
Stem Cells Divides by mitosis to yield:
- Either two daughter cells that are stem cells like itself (Hematopoietic stem cell).
- Stem cell
- Partially Specialized Progenitor Cell
________________ is the characteristic that makes a stem cell a stem cell.
Self-renewal
Inner cell mass of very early embryo; somatic cell nuclear transfer into egg cell
Embryonic stem cell
Genes or other chemicals reprogram somatic cells nucleus; no embryos required
Induced pluripotent stem cell
Somatic cells that normally function as stem cells, from any stage of development from fertilized ovum through elderly
“Adult” stem cell
Four Basic Applications of Stem Cells
- Drug discovery and development
- Observe the earliest sign of disease
- Creates tissues and organs for implants, transplants, or infusions into the bloodstream.
4.Through the Induced Pluripotent Stem Cell or iPS cells
what is cloning
creates a genetic replica of an individual
Reasons why cloning cannot produce an exact replica of a person
- premature cellular aging
- altered gene expression
- more mutations
- x-inactivation
- mitochondrial DNA
Used for growth, repair, and asexual reproduction
Mitosis
Used for sexual reproduction, producing new gene combinations
Meiosis
In humans, completes after sexual maturity
Meiosis
Chromosome number of daughter cells half that of parent cell (1n)
Meiosis
Daughter cells genetically different
Meiosis
How many daughter cells does mitosis have
2 daughter cells per cycle
Daughter cells genetically identical
Mitosis
Chromosomes number of daughter cells same as that or parent cell (2n)
Mitosis
Mitosis occurs in ___________
somatic cells
Occurs throughout life cycle
Mitosis
