Question

What is common for cuscuta , ticks and leeches

Answer 1

Cuscuta is a parasitic plant which wraps itself around the stem of a host plant. It then develops specialised root-like haustoria which invade the vascular system of the host plant and drains it of nutrients.

Ticks are parasitic arachnids, which attach themselves to the skin of a host animal. They bite the animal and suck its blood.

Leeches are parasitic flatworms which also feed on blood by attaching themselves to the skin of their host.

Thus all of these organisms are parasites, which cause harm to their hosts by living off them. 

Answer 2

Answer:

All of them are parasites. They live on or inside the body of another organism to get food. They always harm their hosts.