Chapter 10: Cell Growth and Division

10.1 - Growth, Division, and Reproduction

Mr. M. Varco Saint Joseph High School

Limits to Cell Size• When a living thing grows, what happens to its cells?

• Nearly all cells can grow in size, but eventually divide after growing to a certain point.

Limits to Cell Size• There are two main reasons why cells must divide:

1. The larger a cell becomes, the more demands the cell places on its DNA 2. A larger cell is less efficient at moving nutrients into and waste out of the cell

Limits to Cell SizeInformation “Overload”

• Living cells store critical information in DNA.

• As cells increase in size, its DNA does not, resulting in the inability of the cell to meet its needs.

Limits to Cell SizeExchanging Materials

• The rate of material and waste exchange across the cell membrane is dependent upon the cell’s volume

• If a cell is too large, it would be more difficult to get sufficient materials in and waste out.

Cell Division and Reproduction• The process by which a cell divides into two daughter cells is called

cell division.

• Before a cell divides, it must replicate its DNA.

• Each daughter cell will receive one complete copy of genetic information.

Cell Division and Reproduction• For many single-celled organisms, cell division is the only method of

reproduction and survival

• The production of genetically identical offspring from a single parent is known as asexual Reproduction

• When conditions are right, the faster they reproduce, the better their chance of survival

Cell Division and Reproduction• For most animals and plants, reproduction involves the fusion of separate

parent cells in a process called sexual reproduction

• Offspring produced by sexual reproduction inherit some of their genetic information from each parent

Cell Division and Reproduction• For most animals and plants, reproduction involves the fusion of separate

parent cells in a process called sexual reproduction

• Offspring produced by sexual reproduction inherit some of their genetic information from each parent

Asexual Reproduction Sexual Reproduction

Parent cells

Offspring

Cell Division and Reproduction• Sexual reproduction is more time consuming, but offers species

genetic diversity

“Clint” the Chimp

Cell Division and ReproductionOverview:

• For single-celled organisms, asexual reproduction is considered a survival strategy

• (+): Faster reproduction means a greater chance of survival • (-) : Lack of genetic diversity

• Sexual reproduction offers several survival benefits as well: • (+): Provides genetic diversity among species • (-) : It is very time consuming