Bacteria require three conditions to multiply: food, warmth, and moisture.

• A. Food, warmth, and moisture
• B. Food only
• C. Warmth only
• D. Moisture only

Answer: (A)

Bacteria multiply only when they have three things: nutrients, warmth, and moisture. Food provides the substances they use to grow and build cell material. Warmth speeds up their metabolic processes and allows replication to occur; without a suitable temperature, their enzymes don’t work efficiently, so growth slows or stops. Moisture supplies the water needed for biochemical reactions and transport of nutrients inside the cells; in very dry environments, metabolism can’t proceed well. Because all three are required for growth, having just food, or just warmth, or just moisture won’t support multiplication. The description that includes all three best captures what bacteria need to multiply.