1. Why is cell size limited?
How does the surface area to volume ratio affect a cell?
The larger the surface area to volume ratio, the more efficiently the cell can get nutrients
Why is cell size limited?
If cells get too big, their volume increases faster than surface area; the cell can’t get nutrients in and wastes out fast enough
If cells are too small, the organelles can’t fit and function correctly
What are the two major phases of the cell cycle?
Interphase and M-phase

2. G1, S, and G2 What are the 3 phases of Interphase?
What happens during G1 of Interphase?
normal growth and functioning; organelles are copied
What happens during S of Interphase?
DNA is replicated (copied)

3. Mitosis and Cytokinesis
What happens during G2 of Interphase?
normal growth and functioning
Why is replication of DNA and the cell’s organelles important?
When the cell divides, it will need to give each daughter cell all of the organelles and a full set of DNA
What are the two major events that occur during the M-phase?
Mitosis and Cytokinesis

4. Cell Division What occurs during the M-phase?
What is mitotic cell division (mitosis and cytokinesis)?
When a parent cell divides into two identical daughter cells
What happens during mitosis?
The parent cell DNA (in the nucleus) is organized and divided between the two new daughter cells (in two new nuclei)

5. How does cytokinesis occur in plant cells?
What happens during cytokinesis?
The cytoplasm of the parent cell is divided to create two daughter cells
How does cytokinesis occur in plant cells?
A cell plate grows between the two cells and forms a new cell wall on each side
How does cytokinesis occur in animal cells?
The cell membrane pinches inward to form a cleavage furrow until the two cells are pinched apart

6. They have a rigid cell wall.
Why can’t plant cell membranes pinch inward during cytokinesis?
They have a rigid cell wall.
What is the purpose of mitosis in unicellular organisms?
Asexual reproduction: one organism creates two new organisms
What is the purpose of mitosis in multicellular organisms?
Replace dying cells or help the organism grow

7. Mitosis occurs in what type of cells? Somatic (body) cells
What is the most basic form of DNA?
Double helix
What are the building blocks (monomers) of DNA?
nucleotides

8. Proteins called histones
What does DNA wrap around to start condensing?
Proteins called histones
What is chromatin?
DNA wrapped around histones and condensed into “spaghetti” form
When chromatin coils up on itself into a supercoil, what is formed?
Chromosomes

9. What is half a chromosome called?
chromatid
A chromosome that has its copy attached to it (from the S phase of Interphase) is made up of 2 what?
Sister chromatids
Sister chromatids are held together at the what?
centromere

10. What form of DNA is present during Interphase?
Chromatin
What form of DNA is present during mitosis?
chromosomes
What is the role of spindle fibers during cell division?
To help organize and separate the DNA

11. What do centrioles do during cell division?
Organize the spindle fibers
Why do cells divide at different rates?
Some cells need to be replaced more often than other types of cells according to their function in the body
What are the four phases of mitosis?
Prophase
Metaphase
Anaphase
Telophase

12. What happens during Prophase?
The nucleolus and nuclear membrane “break up” and temporarily disappear.
Chromatin has condensed into chromosomes, each consists of two identical sister chromatids
Centrosomes and Centrioles migrate to opposite sides of the cell
Spindle fibers grow from the centrioles and radiate toward the center of the cell.
What happens during Metaphase?
Spindle fibers attach to the chromosomes and help line the chromosomes up across the center of the cell on an imaginary line called the metaphase plate or cell equator
The chromosomes line up across the center of the cell on an imaginary line called the metaphase plate.
Microtubules attach to the centromere of each chromosome from both poles of the spindle.

13. Interphase What happens during Anaphase?
Spindle fibers shorten, breaking sister chromatids apart to form separate chromosomes. The chromosomes are pulled to opposite ends of the cell
What happens during Telophase?
Chromosomes begin to unwind back to chromatin.
The nuclear envelope and nucleolus reappear in each daughter cell
The spindle disappears
What is this
phase?
Interphase

14. What is this
phase?
Prophase
Metaphase
Anaphase

15. What is this
phase?
Telophase