Question

multiple select question
select all that apply
which of the following attributes make agar an ideal solidifying agent for culturing media? more than one answer may be correct.

□ it holds moisture and nutrients.

□ it is a nutrient for many microbes.

□ it is solid at room temperature.

□ it is readily available but expensive.

□ it can be inoculated and poured at temperatures that do not harm microbes or people.

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Explanation:

1. Analyze "It holds moisture and nutrients": Agar has a porous structure that can retain moisture and nutrients, which is beneficial for microbial growth, so this is correct.
2. Analyze "It is a nutrient for many microbes": Agar is not a nutrient for most microbes (it's a polysaccharide that most microbes can't metabolize), so this is incorrect.
3. Analyze "It is solid at room temperature": Agar solidifies at room temperature (around 25°C), making it suitable for solid media, so this is correct.
4. Analyze "It is readily available but expensive": Agar is relatively inexpensive and readily available, so the "expensive" part is wrong, making this incorrect.
5. Analyze "It can be inoculated and poured at temperatures that do not harm microbes or people": Agar melts at around 85 - 95°C and solidifies at around 32 - 40°C, so it can be handled at temperatures (like around 45 - 50°C for pouring/inoculating) that are safe for microbes and people, so this is correct.

Answer:

• It holds moisture and nutrients.
• It is solid at room temperature.
• It can be inoculated and poured at temperatures that do not harm microbes or people.