December 1 st, 2014

Chapter 10 Big Ideas in Biology = 1) 2) Essential Question = How does a cell produce a new cell?

Random Cell Info: trillion cells in an adult human body Where 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 Volume Understanding 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 “__________” cell Solves 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 volume Increase 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 Reproduction In single-celled organisms, cell division is a form of reproduction called asexual reproduction. = Examples:

Sexual Reproduction =

Compare/Contrast Asexual Sexual

Sexual Reproduction Advantages Disadvantages

Asexual Reproduction Advantages Disadvantages