Diversity of Life

BIOL 1309

Which gases were hypothesized by Oparin to be found in the Earth’s atmosphere billions of years ago?

Methane, ammonia, water, and hydrogen

How were amino acids created according to the Electric Spark Theory?

An electric spark from lightning created amino acids within warm ponds.

How were amino acids created according to Clay Theory?

Mineral crystals in clay linked together to build molecules.

What were the first living organisms?

Bacteria.

What is a prokaryote?

A single celled organism with NO nucleus.

Scientists around the world agreed that life may have originated from non-living matter in a series of
four steps. What is the first step?

Formation of monomers- atoms bonding together to form simple organic molecules.

Scientists around the world agreed that life may have originated from non-living matter in a series of
four steps. What is the second step?

Formation of polymers- monomers joined together to form DNA, RNA, proteins, lipids, and carbs.

Scientists around the world agreed that life may have originated from non-living matter in a series of
four steps. What is the third step?

Formation of the first true cell- polymers are enclosed in a membrane.

Scientists around the world agreed that life may have originated from non-living matter in a series of
four steps. What is the fourth step?

Formation of a living cell- protobiont acquired the ability to self-replicate and metabolize.

Which internal structures are seen in all prokaryotic cells?

Cytoplasm, ribosomes, nucleoid, and plasmids.

Which external structures are seen in all prokaryotic cells?

Cell wall, plasma membrane, capsule, pili, flagellum, and endospore.

How do prokaryotes reproduce?

Binary Fission.

Most prokaryotes are _______________, meaning they require an outside source of _______

heterotrophs, food.

Some are ____________________, meaning they require energy from breaking down certain _________
to produce their own food

chemoautotrophs, chemicals.

Some prokaryotes are _________________, meaning they require energy from the ________________
to produce their own food.

photoautotrophs, sunlight.

How are bacteria classified?

Differences in cell walls, shapes, and growth requirements.

If the cell wall has a thick layer of peptidoglycan, then it will be stained _______________ and
considered Gram-____________________

purple, positive

If the cell wall has a thin layer of peptidoglycan, then it will be stained _____________ and considered
Gram-______________________

pink, negative

Gram stains also help distinguish the different shapes.
Bacteria have five shapes. What are the shapes and the technical names used to describe the shape?

1. Round/Cocci

2. Rod-like/Bacilli

3. Comma shaped/Vibrio

4. Spiral/Spirilla

5. Corkscrew/Spirochetes

There are certain conditions that promote bacterial growth more than others.
These conditions include….

Temperature, moisture, pH and environmental oxygen.

Why are archaean bacteria known as extremophiles?

They have the ability to live in extreme physical and chemical conditions.

Archaean bacteria are classified based on which ____________________________ they favor.

environment.

What environment do methanogens favor?

Anaerobic environments.

What environment do halophiles favor?

Very salty environments.

What environment do thermophiles favor?

High-temp environments.

What environment do acidophiles favor?

Highly acidic environments.

Capsule

Cell wall covered by a sticky layer that helps the cell stick to surfaces.

Pili

Hair-like structures that attach to specific surfaces or transfer DNA from cell to cell.

Flagellum

Whip-like structure that aids movement

Endospore

thick-walled structure to protect the cell when environmental conditions are unfavorable.