Lesson 2: Mitosis and Meiosis

Cell Division

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.

• Prophase

• Metaphase
• Anaphase

• Telophase

Define PMAT

Prophase

• First stage of mitosis

• Nucleolus disappears

• Where chromatin will condense into chromosomes.

• Centrioles will move to opposite ends

• The DNA condenses and organizes, and the classic chromosome structure appears.

ProMetaphase

Nuclear membrane breakdown happens.

Metaphase

Aligning of chromosomes

Anaphase

Chromosomes start to separate through a shortening of the microtubules attached to the kinetochores.

Telophase

• Nuclear membrane starts to appear.

• Cytoplasm divides to form 2 cells.

• Spindle fibers are broken up

• Chromosomes uncoil and return to an uncondensed state.

Cytokinesis

• Process where a cell is compressed by a contractile ring that divides the cell in nearly equal halves.

• The organelles in the cell have been replicated and are now divided into 2 halves of the cell.

• Includes mitochondria, golgi bodies, chloroplasts, and the rough ER

Meiosis

• 4 daughter cells

• Gamete cells (sex cells)

• Cell division that halves the number of

chromosomes to form haploid gametes.

Gametes

refers to sex cells, germline cells, and haploid (1 copy of each type of chromosome). Sperm (male, oocyte/egg (female)

Germ-line

The cells that undergo meiosis to produce gametes are called _____ cells.

Recombination

crossing over, chromosomal material is exchanged.

Prohase II

each daughter cells have 23 chromosomes. No synapsis or crossing over.

Mitosis

Used for growth, repair, and asexual reproduction

Meiosis

Used for sexual reproduction, producing new gene combination

Interphase

phase wherein division has not yet occurred. By mitosis and meiosis.

G1 , S, G2

3 phases of interphase

G1

• Growth stage of interphase

• Cells grow to its full size

• Performs many biochemical functions that aid the organism.

G0

• Quiet stage

• Cell divides if it continues to synthesis or undergo cell death or cell differentiation.

Synthesis (S)

• Important because it is where nucleus replicates.

G2 (growth 2)

• Completed mitosis/growth stage is completed.

• Once the cell has duplicated DNA in the nucleus and two centrosomes have appeared in the cytoplasm, mitosis can begin. For a typical eukaryotic cell this will last about 80 minutes.

Apoptosis

• Form of a cell death which is normal in growth and development.

• Precise genetically sequence of events like mitosis.

CELL CYCLE

Series of events or a sequence of activities as the cell prepares for cell division and then divides.

Stem Cell

Self-renewal is the characteristic that makes a _______ a _____.

Neutrophil

1st responder, invading bacteria and viruses

Monocytes

macrophage, bluish-gray tinge

Eosinophils

parasitic infection, orange

Basophils

0-2%/0-1%, allergies, dark purple