White blood cells work by recognizing invading pathogens by their surface fragments, called .

white blood cells that systematically envelop and kill pathogens such as bacteria, viruses, and fungi, worn-out body cells, and cells that have become cancerous. their surface fragments, called antigens, literally antibody generators.

Explanation:

the answer is b)3/8x+1

1. a host loses nutrients to a parasite

2. a parasite only benefits when the host is alive (cause if the host dies the parasite dies with it )

3. producers to consumers

4. the tapeworm is a parasite

5. they convert energy from the sun (photosynthesis)

6. sunflower-robin (i think im 80% sure)

7. producer

8. consumer

9. prey

10. fresh water snails ( cause the green algea is the producer and the snails are the primary consumers and the small fish consumer so is the big fish)