What is common to gastropods, cephalopods, and bivalves?

1. a mantle

2. a radula

3. torsion during development

4. an external shell

The key evolutionary transition seen for the first time in annelids is
1. Cephalization
2. Development of a true coelom
3. Metameric segmentation
4. Deuterostome development

Malphighian tubules are

(1) Excretory organs of insects

(2) Excretory organs of annelids

(3) Respiratory organs of insects

(4) Respiratory organs of annelids

An insect regarded as the greatest mechanical carrier of diseases is

(1) Pediculus

(2) Cimex

(3) Musca

(4) Xenopsylla

Kala azar and oriental sore are spread by

(1) Housefly

(2) Bed bug

(3) Sand fly

(4) Dragon fly

Adult Culex and Anopheles can be distinguished with the help of

(1) Mouth parts/colour

(2) Sitting posture

(3) Antennae/wings

(4) Feeding habits

A larval stage occurs in the life cycle of all members of the group

Tracheae of Cockroach and Mammal are similar in having

(1) Paired nature

(2) Non-collapsible walls

(3) Ciliated inner lining

(4) Origin from head

What is common among Scorpion, Crab, Honey bee and Siver fish?

(1) Compound eyes

(2) Jointed legs

(3) Poison glands

(4) Metamorphosis

Insects never attain a huge size. The reason for this is