Why do cells divide?
1. Avoid getting too large
2. Growth and development of organisms
3. Repair damaged tissue
What phases make up interphase?
G1, S, G2
What happens in G1?
Growth, normal metabolic activities
What happens in the S phase?
DNA synthesis and replication
What happens in the G2 phase?
Growth and preparation for reproduction
What is the G0 phase?
resting phase, cells are metabolically active but not destined to multiply
What controls cell division?
Checkpoints and regulatory proteins called cycling, which bind with CDK's to function as enzymes
How do bacteria reproduce? (Prokaryotic cell division)
Binary fission
What happens in binary fission?
-singular circular chromosome copies itself
-cell pinches inward until it splits in two
Why is prokaryotic reproduction asexual?
One parent generates two daughter cells that are genetically identical to itself
What are the two stages of eukaryotic cell division?
Karyokinesis and cytokinesis
Karyokinesis
Division of the nucleus through mitosis or meiosis
Cytokinesis
division of the cytoplasm, parent cel cytoplasm and organelles separate into daughter cells
Chromatin
Stringy, unwound form of DNA present during interphase
Chromosomes
Tightly wound packages of DNA present during cell division (only visible during M phase)
Chromatids
Two identical copies (halves) of a replicated chromosome
Centromere
Point at which chromatids are connected
Spindle Fibers
Protein "drawstrings" that attach to centromeres of chromosomes and to centrioles at ends of cells
Diploid
Having two sets of chromosomes (maternal and paternal) 2n=46