Topic 1A-B: Theories of Life

Question 1

What is biology?

Answer 1

• The study of life and living organisms

Question 2

The 5 characteristics to be considered a living organism

Answer 2

1. They need energy (usually in some form of food)
2. They produce waste material
3. They reproduce (ex. sexual, asexual)
4. They respond and adapt to the environment
5. They grow

Question 3

Which theory was Aristotle responsible for?

Answer 3

The Theory of Abiogenisis (also called spontaneous generation)
- That life can come from non-living matter

Question 4

Francesco Redi’s experiment

Answer 4

• the presence of maggots in decomposing meat doesn’t result from spontaneous generation but from eggs laid on the meat by flies
• Experiment: He had six jars, half left in open air and half covered with fine gauze that permitted air circulation but kept out flies, were filled with either an unknown object, a dead fish, or raw veal
• The fish and veal rotted in both groups, but maggots only formed in the jars open to air

Question 5

Louis Pasteur’s experiment

Answer 5

• Widely seen as having settled the question of spontaneous generation
• Experiment: He boiled a meat broth in a flask that had a long neck that curved downward, like a goose
  
  • The bend in the neck prevented falling particles from reaching the broth while still allowing the free flow of air
  • The spoilage of liquid was caused by particles in the air rather than the air itself

Question 6

Spontaneous generation

Answer 6

• The idea that living organisms can arise from non-living matter through natural processes
• It has been disproven by scientific experiments

Question 7

Theory of Abiogenesis

Answer 7

• Same idea as a spontaneous generation but is based of scientific evidence and experimenation

Question 7

Robert Hooke

Answer 7

• Known for his work with microscopes and invented the term “cell”

Question 8

Anton van Leeuwenhoek-

Answer 8

• First person to observe/describe microorganisms which he called “animalcules”

Question 9

Schleiden and Schwann

Answer 9

• Credited with developing the cell theory

Question 10

Virchow

Answer 10

• Found that cells divide to produce more cells
• “Where a cell exists, there must have been an existing cell”

Question 11

Cell Theory

Answer 11

1. All organisms are made up of one or more cells
2. The cell is the smallest functional unit of life
3. All cells are produced from other cells