Biradial symmetry is most obvious in:
1. | Cnidarians | 2. | Ctenophores |
3. | Nematodes | 4. | Echinoderms |
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:
I. Open circulatory system | II. A shell | III. Radula |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II and III |
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:
1. | Lampreys have direct development, but Hagfishes go through a larval stage followed by metamorphosis into a juvenile form. |
2. | Unlike jawed vertebrates, which have three semicircular canals in each inner ear, lampreys have only two and hagfishes just one. |
3. | The hagfish blood is isotonic with seawater, while lampreys appear to use the same gill-based mechanisms of osmoregulation as marine teleosts. |
4. | Both hagfishes and lampreys have a single gonad. |
Which of the following is a ‘fish’ in true taxonomic sense?
1. Shellfish
2. Lungfish
3. Cuttlefish
4. Crayfish
Nematodes lack:
1. A body cavity
2. Collagenous cuticle
3. Circumferential muscles in body wall
4. A hydrostatic skeleton
Rhabdom is a part of:
1. | the compound eye of an arthropod |
2. | the protonepohridia of flatworms |
3. | the second stage larva of mollusks |
4. | water vascular system of echinoderms |
The following schematic diagram of a part of skeleton can be that of a/an:
1. | Amphibian | 2. | Reptile |
3. | Bird | 4. | Mammal |