Haemoglobin is dissolved in the blood plasma of:

Annelids are ..........

In which phylum of animals is the digestive tract either straight or coiled?

In which of the following organisms is the genetic material organized into chromosomes?

$A$ student was given a specimen to identify on the basis of the characteristics given below.
$(i)$ They are metamerically segmented.
$(ii)$ Presence of closed circulatory system.
$(iii)$ They have circular and longitudinal muscles for locomotion.
Identify the specimen.

Which animal in the phylum $Annelida$ exhibits separate sexes (dioecious)?