Consider the two statements:

I.	The similarity between notochord and stomochord is due to convergent evolution.
II.	Both arise from a common ancestry and exhibit homology.

 

1.	Both I and II are correct and II explains I
2.	Both I and II are correct but II does not explain I
3.	Only I is correct
4.	Both I and II are incorrect

A viviparous nematode is:
1. Enterobius vermicularis
2. Trichuris trichiura
3. Trichinella spiralis
4. Ascaris lumbricoides

A trochophore larva is shared by members of:
1. Molluscs and Annelids
2. Molluscs and Arthropods
3. Annelids and Arthropods
4. Molluscs and Nematodes

Biradial symmetry is most obvious in:

A very rare reproductive system seen in Coenorhabditis elegans is described as:
1. Androdioecy
2. Faculatative sexuality
3. Meiotic parthenogenesis
4. Mitotic parthenogenesis

All mollusks do not have:

In nematodes:
1. The head is radially symmetrical while the body is bilaterally symmetrical.
2. The body is radially symmetrical while the head is bilaterally symmetrical.
3. Both body and head are radially symmetrical.
4. Both body and head are bilaterally symmetrical.

The structures shown in the given diagram in a cartilaginous fish are:

1. Mechanoreceptors
2. Thermoreceptors
3. Electroreceptors
4. Thigmoreceptors

Identify the incorrect statement regarding cyclostomes:

Which of the following is a ‘fish’ in true taxonomic sense?
1. Shellfish
2. Lungfish
3. Cuttlefish
4. Crayfish