BIO 392 Notes CELL GROWTH & DIVISION ch. 10

I.  SURFACE AREA TO VOLUME RATIO

A.  Size is Important

1. Smaller is Better

2.  The bigger the cell becomes…

a.  the more demands the cell places on its ______

b.  the more trouble moving enough ______across the cell membranes

B.  Exchanging Materials

1.  Rate at which ______of wastes, nutrients, gases takes place depends on the surface of the cell

a.  Surface area = ______x ______x ______

2.  Rate at which nutrients and gases are ______and wastes are made depends on volume of the cell

b.  Volume = ______x ______x ______

C.  Surface to Volume ratio

1.  Volume increases ______than surface area when a cell is growing

a.  Exchange of materials cannot keep up with the demand

2.  Smaller cells have a ______surface area to volume ratio

a.  Means there is ______surface area for materials to fit into

II.  Cell Division

A.  In order to stay the same size, cells must divide

1.  Split in 2: ______

2.  Are EXACT copies of each other à ______

3.  Before dividing, the cell must duplicate everything ______

so that everything is the same

B.  Prokaryotes are simpler (no organelles)

1.  After DNA is copied, cell splits in two

2.  Each new cell contains a copy of the DNA called ______

3.  Example of ______reproduction

C.  Cell Division in Eukaryotes

Occurs in stages:

1.) Preparation

- ______

2.) Division of ______

3.) Division of ______

III. Chromosomes

A. Structure that carry ______

1.  Made up of DNA and protein (______)

2.  DNA coils very tightly à degree of coiling leads to whether DNA is ______

B. Each eukaryote has a characteristic ______of chromosomes in the nucleus of each cell.

1.  Examples (singles, divided by 2 would be pairs)

–  Humans- ______

–  Dog- 78

–  Housefly- 12

–  Potato plant- 48

–  Cat- 38

–  Aspergillus (fungus)- 8

–  Drosophia (fly) - _____

–  What is a chromosome?

C. Degree of coiling

1. While the cell is “resting”, you cannot see the chromosomes: it is unwound

a. Called ______

2.  While the cell is dividing, you can see the chromosomes

a.  Wound up

b.  Made of two ______connected by a ______

IV. The Cell Cycle

A.  Overview

1.  Occurs in ______cells

2.  Definition à It is the period of time from the beginning ______

______

3.  Cell ______its contents so that it is ready to divide into 2 completely independent cells

4.  The Cell Cycle

B.  Consists of 4 phases

1.  _____ à intense growth and activity; new proteins and organelles are produced

2.  S phase à copying of ______

3.  _____ à intense growth and activity; new proteins and organelles are produced

  1. ______of the three phases

4. M phase – mitosis à the division of the cell ______

C.  Cell Cycle Rates

àCells do not move through the cell cycle at the same rate

1.  Cells in a developing embryo replicate rapidly- _____ minutes

2.  Average time of cell cycle- ______

3.  Lining of esophagus- 2-3 days Lining of small intestine- 1-2 days

4.  Lining of large intestine- 6 days Red blood cells-120 days WBC- 10hrs-decades

5.  Cell stops growing in ____ phase

a.  Once conditions are right, cell will leave G1 and go through S phase, G2, and M phase

b.  Some cells stop going through the cell cycle.

  1. They are permanently in the _____stage (normal cell function).
  2. This stage is referred to as ______

c.  Cardiac muscle

d.  Nerve cells (most)

e.  Red blood cells

D.  M phase

1.  Cell division

a.  Process in which the cell divides into two independent cells à ______

2.  Process is called ______in eukaryotes

3.  and ______ in prokaryotes

MITOSIS Chapter 10-2

I. Mitosis

à Time of cell division

A.  Divided into four main phases

1.  Prophase

2.  Metaphase

3.  Anaphase

4.  Telophase

II. Cell Cycle Stages

A.  Prophase

1.  ______of the four phases

2.  Appearance of chromosomes

  1. Creation of ______
  2. Attached at the ______

3.  Nucleus undergoes several changes

  1. ______begins to breakdown

4.  ______begins to form

  1. Series of microtubules that span the cell
  2. Purpose is to ______

5.  Chromosomes attach to the spindle at the ______

  1. In animals, spindle is created by the ______
  2. In plants, spindle is created between the ______

i.  Plants do not have centrioles

B. Metaphase

1.  ______phase of mitosis

2.  Chromosomes line up in the middle of the cell

C. Anaphase

1.  Centromeres split

a. Sister chromatids are pulled to the ______of the cell

D. Telophase

1. ______breaks down

2. ______forms around the

chromosomes again

3. Chromosomes ______again

II. Cytokinesis

àProcess of the ______

A.  Animals

1.  the cell pinches in ______

B.  Plants

1.  a ______is created in the middle of the cell