Identify the following characteristics as urochordates, cephalochordates, or both using the following key: U= urochordates C=cephalochordates U/C=both ___ Sea lancelet
___Body enclosed in a nonliving tunic
___Filter feeders; resemble worm or larval fish
___Sea squirt
___Segmented myomeres
___gill slits
___filter feeder; takes in water through an incurrent siphon and eliminates water and waste through an excurrent siphon

The mutualism refers to a symbiotic relationship, which benefits both the species involved.

In this case, the birds eat the seeds of the fruit, which help them in getting food. The food is important for the survival of the bird. In return, the bird transfer the seed of the plant from one place to another, so they help in seed dispersal. The seed dispersal reduces the risk of competition and increases the chances of survival. So, in this case both the organism is getting benefited .