Biology Chapter 14 Section 2 Study Guide

1) Spontaneous Generation;
2) Theory of Biogenesis
The two earliest hypotheses about origin of life?

Redi observed that maggots, the larvae of flies, appeared only in the flasks that were open to flies. He hypothesized that flies – not meat – produced other flies.
Redi’s experiment and how it was against spontaneous generation.

Theory that living things come only from other living things

Idea that living things come from non-living things
Spontaneous generation

“Primordial soup hypothesis”

1) Formation of organic compounds
2) Formation of proteins
3) Genetic code
4) Foundation of membrane
5) Cellular evolution

The steps in which life originated according to modern ideas.

Biogenesis was true even for microorganisms.

A) The swan-necked flasks remained sterile as long as they stayed upright
B) When the flasks were tilted, microorganisms could enter the broth
C) The microorganisms grew in the broth, turning it cloudy. This showed that microorganisms do not appear spontaneously

Pasteur’s experiment on biogenesis.

Atmosphere of early life – methane, ammonia, hydrogen

(Draw picture)

Explain the experiment performed by Miller and Urey to explain the formation of organic molecules in early Earth.

What base was needed by a amino acids to form proteins?

What were the first cells like?

Where did the first cells live on our planet?

The closest relative to the first cells still living on our planet.

The first cells that produced oxygen were called?

Formed iron oxide, then later collected in the atmosphere
What happened to the first oxygen that was produced?

1)The relationship between cells became mutually beneficial;
2) The prokaryotic symbiots became organelles
Two conditions that gave way for the formation of eukaryotic cells.

Mitochondria and Chloroplasts were formerly small prokaryotes and they became organelles in eukaryotic cells
Explain the endosymbiont theory.