Biology Cell Cycle + DNA Review

Mitosis

Prophase: DNA condenses into chromosomes

Metaphase: chromosomes line up in the middle of cell

Anaphase: sister chromatids split apart and go to opposite sides of cell

Telophase: 2 new nuclei are formed

+ Cytokinesis: cells split apart to make 2 new cells

Interphase

G1: cell grows

S: DNA replicates (synthesis)

G2: growth and preparation for mitosis

G0:

• a resting state, no division, is activated when resources are insufficient or when cell receives a signal
• some cells never exit G0 (ex. neurons)

Apoptosis - programmed cell death

Cancer cells:

• progress faster through cell cycle
• don’t function properly
• don’t go through apoptosis
• continuously divide
• stack on top of each other

Cells need to divide for:

• growth
• replacement
• repair

Daughter cells have same number of chromosomes as parent cell because DNA is replicated beforehand.

Chromosome = tightly wound DNA

Chromatin = genetic material (spaghetti ball)

Nucleotides = connected by covalent bonds

Nitrogenous bases = connected by hydrogen bonds

Semi-conservative process:

• 1 strand is template (one strand from original full DNA strand)
• 1 strand is new, based off of template due to chargaff’s rule (made by DNA polymerase)

nucleic acid → made of nucleotides → made of nitrogenous base, sugar, + phosphate