Post on 21-Dec-2015
10.1Cell Growth, Division, and
Reproduction
December 1st, 2014
Chapter 10Big Ideas in Biology =
1)
2)
Essential Question = How does a cell produce a new cell?
Random Cell Info:60- 100 trillion cells in an adult human bodyWhere do all these cells come from?!
A single fertilized cell! All cells not the same in your body
Differentiated cells = differentiation
What are some of the difficulties a cell faces as it increases in size?
1) the larger a cell becomes, more demands
the cell places on its DNA. DNA provides information to build new
molecules, controls things cell does and needs.
DNA does not grow, would be like an “information crisis,” if cell grew too large.
After a while DNA cannot serve all the needs of the growing cell…so division is necessary.
What are some of the difficulties a cell faces as it increases in size?
2)Food, oxygen, and water enter a cell through
the cell membrane. Waste products leave in the same way.
The rate at which this exchange takes place depends on the surface area of a cell.
The rate at which food and oxygen are used up and waste products are produced depends on the cell’s volume.
The ratio of surface area to volume is key to understanding why cells must divide as they grow.
Surface Area and VolumeUnderstanding the relationship between a
cells surface area and it’s volume is key to understand that a cell must divide rather than continue to grow.
The surface area does not __________ as fast as the volume.
Ratio of Surface Area to Volume Imagine a cell shaped like a cube. As the
length of the sides of a cube increases, its volume increases faster than its surface area, decreasing the ratio of surface area to volume.
If a cell gets too large, the surface area of the cell is not large enough to get enough oxygen and nutrients in and waste out.
Cell Division:=
Original cell called the “__________” cellSolves the information “overload” and
exchanging materials issues.
Cell Division Solves…1) Information “Overload” by:
First, replicating its DNA.Each daughter cell gets a complete set of DNA
2) Material Exchange Inefficiency by:Reducing volumeIncrease the ratio of Surface area to volume
for each daughter cell. Allows for more efficient exchange, movement
of materials.
Reproduction =
One of the most important characteristics of living things
Asexual ReproductionIn single-celled organisms, cell division is a
form of reproduction called asexual reproduction.
=
Examples:
Sexual Reproduction=
Compare/ContrastAsexual Sexual
Sexual ReproductionAdvantages Disadvantages
Asexual ReproductionAdvantages Disadvantages