1. Why does the immune system make memory cells? 2. Plants follow a reproduction pattern called alternate generations. Explain the two processes in alternate generations.

3. Describe the difference between sexual and asexual reproduction. Give at least one example organism for each type.

4. Many of your body’s responses operate off of either negative or positive feedback loops. When you are cold, you shiver. Explain why that happens.

But cells in our immune system can remember old foes just fine, and we've never really been sure exactly how they manage it. A new study has filled in missing details on the steps our body takes to remember pathogens, finally revealing the steps our immune cells take to preserve a reference library of past battles.

the answer is b

explanation:

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