Exam 2 Micro Part 1

What is NOT a Physical Factors Affecting Cell Growth

• Temperature

• pH (potential Hydrogen)

• Osmotic pressure

• nutrient availability

What is the optimal pH range for the growth of most bacteria (neutrophiles)?

• 2.0 – 4.5

• 4.5 – 6.0

• 6.5 – 7.5

• 8.5 – 10.0

Which organism can survive at an extremely low pH of 1?

• Bacillus subtilis

• A sulfur bacteria

• Escherichia coli

• Halobacterium salinarum

Which type of microorganism thrives in environments with a pH of 5.5 or lower?

• Neutrophiles

• Alkalophiles

• Psychrophiles

• Acidophiles

Alkalophiles prefer which of the following environmental conditions?

• Low pH environments

• Neutral pH environments

• pH above 8.5

• Salt-rich environments only

Which of the following microorganisms is an example of an alkalophile growing at pH 10.5?

• Pseudomonas

• Bacillus

• Streptococcus

• Clostridium

Organisms that thrive in high salt concentrations are known as:

• Acidophiles

• Osmophiles

• Halophiles

• Thermophiles

Which of the following are major elements required for microbial growth?

• Calcium and magnesium

• Copper, iron, and zinc

• Carbon, nitrogen, sulfur, phosphorus, oxygen, hydrogen

• Sodium and chlorine

Trace elements such as copper and molybdenum are important because they:

• Provide structural components for the cell wall

• Are used as energy sources

• Act as cofactors for enzymatic activity

• Form the backbone of nucleic acids

Which of the following are considered organic growth factors?

• Water and oxygen

• Amino acids, vitamins, purines, and pyrimidines

• Trace metals

• Lipids and carbohydrates

Tags

NGSS.HS-LS1-6