How to make a human

Essay by affyJunior High, 9th grade March 2009

download word file, 3 pages 5.0

Downloaded 16 times

“How to Make a Human” Revision1.Getting Pregnant (or not?)Humans are multicellular organismsCell theory:Cell Theory refers to the idea that cells are the basic unit of structure in every living thing. new cells are formed from other existing cells and the cell is a fundamental unit of structure, physiology, and organization in all living organisms.

Modern Cell TheoryThe generally accepted parts of modern cell theory include:1.The cell is the fundamental unit of structure and function in living things.

2.All cells come from pre-existing cells by division.

3.Energy flow (metabolism and biochemistry) occurs within cells.

4.Cells contain hereditary information (DNA) which is passed from cell to cell during cell division5.All cells are basically the same in chemical composition.

6.All known living things are made up of cells.

7.Some organisms are unicellular, i.e., made up of only one cell.

8. Others are multicellular, composed of a number of cells.

9.The activity of an organism depends on the total activity of independent cells.

Asexual reproductionIn asexual reproduction, an individual can reproduce without involvement with another individual of that species. The division of a bacterial cell into two daughter cells is an example of asexual reproduction. Asexual reproduction is not, however, limited to single-celled organisms. Most plants have the ability to reproduce asexually.

Sexual ReproductionSexual reproduction requires the involvement of two individuals, typically one of each sex. Normal human reproduction is a common example of sexual reproduction.

Meiosis and Mitosis are methods of cell division in human cellsMitosis occurs in body cells forming identical daughter cells from a parent cell both with the full number of chromosomes.

Meiosis occurs in sexual reproduction forming 4 daughter cells each with half the number of chromosomes of the original cell.

•Normal body cells have 46 chromosomes. Cells that have...