Bacterial contamination can spread quickly because, if the conditions are right,

• A. bacteria reproduce rapidly through binary fission
• B. bacteria require complex nutrients to grow
• C. bacteria are always killed by exposure to air
• D. bacteria cannot survive outside the human body

Answer: (A)

Verified step by step guidance

1. Understand the question is asking why bacterial contamination spreads quickly under favorable conditions.
2. Recall that bacteria reproduce by a process called binary fission, where one bacterial cell divides into two identical daughter cells, leading to rapid population growth.
3. Consider the other options: bacteria requiring complex nutrients is not necessarily true for all bacteria, and some can grow in simple media; bacteria are not always killed by exposure to air since many are aerobic or facultative anaerobes; and bacteria can survive outside the human body in various environments.
4. Identify that the key reason for rapid spread is the ability of bacteria to reproduce quickly through binary fission when conditions such as nutrients, temperature, and moisture are suitable.
5. Conclude that the correct explanation for rapid bacterial contamination spread is their rapid reproduction via binary fission.