Aristotle (384 BC - 322 BC)
a Greek philosopher whose theory of abiogenesis or spontaneous generation was accepted for over 2000 years.
living things could arise from non-living Matter.
created his theories on the origin of life based on his many observations, however, he did not conduct any scientific experiments to test his ideas.
Francesco Redi (1626 - 1697)
Italian physician who used controlled scientific experiments to refute the theory of spontaneous generation
Louis Pasteur (1822 - 1895)
French scientist who finally settled the continued debate of the theory of abiogenesis.
living things could only arise from other living organisms.
smallest functional unit of life
explains and defines the boundary between the living and non-living.
Robert Hooke (1635 - 1703)
looked at cork with a compound light microscope (30X magnification) and was the first to see and name "cells".
Antony van Leeuwenhoek (1632 - 1723)
Dutch linen merchant who first described single-celled microorganisms. He called his sightings "animalcules"
Matthias Schleiden (1804 - 1881) and Theodor Schwann (1810 - 1882)
German scientists who studied cells in hundreds of plants and whose research contributed to the cell theory, stating that "all organisms are made of cells "
German physician who made microscopic observations of cells dividing and completed the cell theory still accepted today.
the first scientist to link illnesses to malfunctioning cells
The Cell Theory
1. All organisms are composed of one or more cells.
2. The cell is the smallest functional unit of life.
3. All cells are produced from other cells.
use to view objects illuminated by visible light
used only one lens (similar to a magnifying glass)
uses two or more lenses placed one on top of the other
specimens are illuminated with a beam of electrons instead of a beam of light. It magnifies up to 1.2 million times
the photograph of the image produced by an electron microscope
transmission electron microscope
scanning electron microscope
confocal laser scanning microscope
scanning tunnelling microscope
sections of DNA that direct the activities of our cells
- changes in the gene can cause improper cell function
eg. Sickle cell anemia
carries all genetic information of the organism, coiled to form chromosomes, found in the nucleus of every cell
4 Bases of DNA
Adenine pairs with Thymine, Cytosine pairs with Guanine
made up of thousands of pairs of DNA bases
Q: Fill in the missing bases on this piece of DNA
A __ T__ G__ C__
mapping the order of all of a gene's bases
Human Genome Project (HGP)
an international project to sequence all 30000 to 40,000 human genes
human gene is "corrected" to help cure a disorder or cancer
most cancers are caused by gene damage, some of which create mutations
changes in the base sequence of a gene
non-cellular structure made of a piece of genetic material enclosed in a protein coat.
In order to reproduce, a virus must infect a cell
a protein that can convert into a harmful particle which can reproduce in living tissue
isolated cells are given nutrients and their growth and division are studied
the generations of cells produced from a culture; can be grown indefinitely in a lab
"blank slate" cells that divide to produce all other types of specialized cells