Q: Q: Parasitic leeches feed off of what?   A: | OPTIONS:
- brain
- tissue
- tumor
- blood
A: blood

Q: Q: What do sharks use to secrete salt to assist in osmoregulation?   A: | OPTIONS:
- ceramic gland
- bladder gland
- blood gland
- rectal gland
A: rectal gland

Q: Q: What system lets flatworms maintain a proper balance of water and salts?   A: | OPTIONS:
- homeostasis
- nervous
- digestive
- excretory
A: excretory

Q: Q: Passive immunity arises from the transfer of what to an individual, without requiring them to mount their own active immune response?   A: | OPTIONS:
- parasites
- bacteria
- viruses
- antibodies

A: antibodies