(Thin Chromatin)
Stretched out, unwound DNA
Looks like spaghetti
Not visible under microscope

What is a Chromosome?
Coiled up (condensed) version of chromatin; easier for moving DNA
(Looks like a slinky)

How many pairs of chromosomes do normal human cells have?

What is the Centromere ?
Holds Sister Chromatids together
Where spindle fibers grab chromosome
(Think: Centro = center mere = middle)

What is the Sister Chromat id ?
Two id entical strands of a chromosome

What are the Centrioles?
Organelle that is present only in
ANIMAL CELLS and creates the spindle fibers
“Centrioles go to the poles”

Name the phases of the
Cell Cycle …
G1 Phase
S Phase
G2 Phase
M Phase

What happens in the G1 Phase?
Growth Phase
When cell gets bigger and makes lots of proteins
1st part of
Interphase

What happens in the S Phase?
“Synthesis” Phase
Makes a copy of the
DNA
Single strand →Double strand
2 nd part of Interphase

What happens in the G2 Phase?
“Growth 2” Phase
Cell is getting ready to divide
Getting organelles and proteins
(Like going to grocery store to get the food to prepare dinner)
3 rd part of Interphase

What happens in the M Phase?
“Cell Division”
Mitosis and Cytokinesis

What is the“Cell Growth and Protein
Synthesis” stage that is the longest phase of the Cell Cycle?
(NOT part of Mitosis)
Includes: G1, S, G2

When does the chromatin begin to condense?
(phase)
Late Interphase

When is the chromatin visible under the microscope?
(phase)

Name the phases of
Mitosis (Nuclear division)
Prophase
Metaphase PMAT
Anaphase
Telophase
“The Pro fessional Met Ana on the Telo phone.”

Name each phase of Mitosis
(not in correct order)
Metaphase Anaphase
Telophase Prophase

What happens in Pro phase?
“P repare ”
Longest phase of Mitosis!!!
•Chromosomes coil up to make easy to move
•Nuclear envelope (membrane) dissolves
•Centrioles make spindle fibers
Spindle fibers (muscles of chromosome) form to help move

What happens in M etaphase?
“M iddle”
Chromosomes are lined up in the middle of the cell
Spindle fibers are attached and centrioles go to the poles

What happens in Ana phase?
“ A part”
Chromosomes get pulled apart by spindle fibers

What happens in Telo phase?
“ The End ” or “ Tidy Up ”
Uncoiling of chromosomes
Nuclear envelope reforms
Spindle fibers go “bye-bye”

What is Cell Cytoplasm & Membrane Division called?
This is the next stage after mitosis.
Actual cell division into two cells dividing into two daughter cells
Cytokenesis
Hint: cyto plasm gets K ut

Cytokenesis in Animal Cells
What structure appears?
Creates a CLEAVAGE
FUR ROW
(Think: Animals have fur )

Cytokenesis in Plant Cells
What structure appears?
Creates a CELL PLATE
(Think: Hard cell wall is like a hard plate )

What are the two new identical cells made in cell division called?
Daughter Cells

Name the two stages of cell division.

What is it called when a mass of cells are growing out of control?
TUMOR

Why do normal cells stop growing when they touch other cells or reach the sides of a petri dish?
Contact with other cells or the sides of the dish signal to the cell to stop growing.
This happens when you cut your finger. The cells grow rapidly to fill in the cut.
When the cells touch, they go back to normal cell cycle.

What signals a cell to start the cell cycle?

What are internal regulators and external regulators?
Internal regulators are proteins that respond to events inside the cell .
External regulators are proteins that respond to events outside the cell.

What is it called when cells have lost their ability to control their growth?

Differentiation

Cells that have not differentiated yet.

When a cell becomes larger, which increases faster:
Volume or Surface Area ?
The bigger the cell gets the less efficient the cell is at doing its job
(function) in the body.

diploid haploid