Which step in the formation of calcitriol is regulated by the parathyroid hormone

The word that would fill this space would be calcium. Calcitonin lowers it, calcitriol increases it, and parathyroid hormones balance it out.

I hope this helped you! Good luck. :)

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)