Why do cells divide? :
The _________ the cell is, the __________the surface area to volume ratio…… there is more outside and less inside.
If a cell is too ________, it takes too __________to get stuff from the outside to the inside.
Types of Cell Division
_______________________ - not sexual reproduction- when cells produce copies of themselves as an organism grows.
_______________________ - when organisms pass on half of their DNA that combines with another set of DNA to make a new organism.
The Cell Cycle
Cells go through a series of steps in a specific order, beginning after a cell has divided
Interphase
G1(gap 1)- ______________________________________________
S (Synthesis)-____________________________________________
G2(gap 2)- ______________________________________________
_________- the division of the nucleus of a cell.
___________- the division of the rest of the cell (the cytoplasm)
_______- cells usually exit the cell cycle after dividing
Bacteria(prokaryotes) are much simpler, doing a process called _________________.
Mitosis
Mitosis is the division of the nucleus , made up of _______ phases:
____________- the nuclear envelope dissolves, DNA condenses.
____________- chromosomes line up along the center of the cell, pulled into place by centrosomes.
____________- chromatids are pulled apart towards centrosomes.
____________- nuclear envelope forms, DNA becomes chromatin.
____________- NOT part of Mitosis, division of the rest of the cell that takes place immediately after telophase.
Cancer
Cells normally only divide to produce _______ or _____, to _______, or to ________.
Cancerous cells continue in the cell cycle when they shouldn't due to damage to ______.
Meiosis
Meiosis is the process by which __________ (sex cells - sperm or egg) are produced.
Meiosis contains the same steps as mitosis, but they occur twice and have important differences.
Since division happens twice, you end up with ______ the DNA at the end.
Miosis vs Meiosis
Mitosis
Meiosis
Starts and ends with a________ (paired) number of chromosomes (humans have 23 pairs of chromosomes, 46 total)
Occurs in____________ for repair or growth.
___________ form of reproduction, producing identical cells.
Starts with a _______ number of chromosomes and ends with a _______ (half, one of each pair) number of chromosomes. Each half from a parent combines to the total.
Occurs in ________________________.
_________ reproduction, creating unique offspring.
