06.Archaea and Bacteria

Which domain has organisms that live in harsh environments?

• Bacteria

• Archaea

• Both

Answer explanation

Archaea are known for thriving in extreme environments, such as hot springs and salt lakes. While some bacteria can also survive in harsh conditions, Archaea are specifically adapted to these extreme habitats, making them the correct choice.

Are archaea multicellular or unicellular?

• Multicellular

• Unicellular

Answer explanation

Archaea are primarily unicellular organisms, meaning they consist of a single cell. Unlike multicellular organisms, they do not form complex structures with multiple cells.

what material are found in most bacterial cell wall?

• cellulose

• chitin

• peptidoglycan

• amylose

Answer explanation

The correct answer is peptidoglycan, which is a polymer consisting of sugars and amino acids. It forms a mesh-like structure that provides strength and rigidity to the bacterial cell wall, distinguishing it from cellulose and chitin.

the Gram-positive bacteria stain purple because

• they form endospore

• they have cellulose layer

• they have thick peptidoglycan layer

• they have thin peptidoglycan layer

Answer explanation

Gram-positive bacteria stain purple due to their thick peptidoglycan layer, which retains the crystal violet dye during the Gram staining process, unlike Gram-negative bacteria that have a thinner layer.

Cyanobacteria are…

• Photoheterotrophs

• Photoautotrophs

• Chemoautotrophs

• Chemoheterotrophs

Answer explanation

Cyanobacteria are classified as photoautotrophs because they use sunlight to convert carbon dioxide and water into glucose and oxygen through photosynthesis, distinguishing them from other types of organisms.

The prefix "halo" such as in halophile most likely means...

• Salt

• High temperatures

• Self-serving

• Gram

Answer explanation

The prefix 'halo' comes from the Greek word 'halos', meaning salt. In biology, 'halophile' refers to organisms that thrive in high-salt environments, making 'salt' the correct answer.

What kind of Archaea would you find in places such as volcanoes and hot vents on the ocean floor?

• Thermophiles

• Halophiles

• Cyanobacteria

• Plasmophiles

• Volcanophiles

Answer explanation

Thermophiles are a type of Archaea that thrive in extreme heat, such as in volcanoes and hydrothermal vents. They are specifically adapted to survive and grow in these high-temperature environments.

How do heterotrophs get their energy?

• By breaking down/eating other organisms

• By breaking down chemicals such as methane

• By doing photosynthesis

• By creating energy via the power of meditation

Answer explanation

Heterotrophs obtain their energy by breaking down or consuming other organisms, as they cannot produce their own food like autotrophs do through photosynthesis.

The Dead Sea is a large salt lake bording Jordan and Israel. It has a salt concentration of 34.2%, which is too hypertonic for most life. What life might still survive and thrive there?

• Halophiles

• Thermophiles

• Heterotrophs

• Cyanobacteria

Answer explanation

Halophiles are organisms that thrive in high-salinity environments like the Dead Sea. They have adapted to survive in hypertonic conditions, unlike most life forms that cannot tolerate such salt concentrations.

What would cyanobacteria be characterized as?

• Phototrophs

• Chemotrophs

• Heterotrophs

• Tealotroph

Answer explanation

Cyanobacteria are characterized as phototrophs because they use sunlight to produce energy through photosynthesis, making them capable of converting light energy into chemical energy.