02d Oxygen requirements, archaea and extremophiles

Which of the following best describes an **obligate anaerobe**?

• Requires oxygen to live

• Can survive with or without oxygen

• Cannot survive in the presence of oxygen

• Uses oxygen when available, but can survive without it

Which of these bacteria requires oxygen for survival?

• Facultative anaerobe

• Obligate anaerobe

• Aerotolerant anaerobe

• Obligate aerobe

Facultative anaerobes:

• Cannot survive without oxygen

• Switch to anaerobic respiration when oxygen is unavailable

• Die in the presence of oxygen

• Only grow in anaerobic environments

Prokaryotes that grow best in hot environments are called:

• Psychrophiles

• Mesophiles

• Thermophiles

• Halophiles

What is the unique form of metabolism found only in archaea?

• Photosynthesis

• Methanogenesis

• Anaerobic respiration

• Chemosynthesis

Which of the following organisms thrive in extremely salty environments?

• Thermophiles

• Acidophiles

• Halophiles

• Alkalophiles

Which of the following bacteria can grow in temperatures up to 121°C?

• Mesophiles

• Thermophiles

• Hyperthermophiles

• Psychrophiles

Archaea are considered extremophiles because:

• They only grow in neutral pH environments

• They can survive in extreme conditions, such as high heat and acidity

• They require oxygen to survive

• They cannot survive in extreme conditions

What type of archaea is commonly found in extremely acidic environments like volcanic hot springs?

• Halophiles

• Psychrophiles

• Acidophiles

• Alkalophiles

The term “extremophile” refers to organisms that:

• Grow only in moderate environments

• Can tolerate a wide range of temperatures and pH levels

• Can survive only in extreme environmental conditions

• Require oxygen for growth