Explain the parasitic adaptations of the leech.

1. 1 · Define in one line. The leech is a sanguivorous ectoparasite; its body is adapted to cling, cut, suck and store blood.
2. 2 · Attachment and cutting.
   • Anterior and posterior suckers hold the host.
   • Three jaws cut a painless Y-shaped wound.
3. 3 · Feeding.
   • Salivary glands secrete hirudin, an anticoagulant.
   • The muscular pharynx sucks blood.
4. 4 · Storage and body.
   • The crop stores blood for months, so there is less need for digestive juices.
   • No parapodia or setae.
5. 5 · Real life. A leech bite keeps bleeding because of hirudin; doctors have used this idea in anti-clotting medicines.
6. 6 · Close in one line. These adaptations make the leech a highly successful blood-sucking parasite.

Scoring tip: Write each adaptation as 'structure + use'. Four clear points earn the four marks.