Share Answer The unique feature of mammals is the presence of diaphragm. It is a membrane that separates thoracic cavity from abdominal cavity. The cavity of other animals is not divided into thoracic and abdominal cavities. Homeothermy, four chambered heart and rib cage are the characters of mammals as well as some other animals also.

Share Answer Uricotelism means excretion of uric acid. Uric acid excretion occurs in organisms which develop in an enclosed egg (where water is severely limited) or which normally experience very dry terrestrial environment as adult organisms. Uric acid is discharged as thick paste or as solid pellet. Egs. terrestrial reptiles, birds, insects, gastropod mollusc etc.

Share Answer It is universally accepted that amphibians (frogs) have originated from fishes. Resemblance of amphibia to fish is seen in most systems of the body. Both are cold blooded. Fish respire by gills and also tadpole of frog respires by gills. To prevent desiccation in air, both usually lay eggs in water.

Share Answer Echinoderms are triploblastic animals with organ system level of organisation. Larval forms possess bilateral symmetry while adults have radial symmetry.

Share Answer Body in arthropoda is segmented. Segments are grouped into 3 forms head, thorax and abdomen. When head and thorax are fused then they are referred to as cephalothorax. Class insecta of arthropoda phylum have body divided into head, thorax and abdomen.

Share Answer Mammals have twelve pair of cranial nerves. Ten pairs of cranial nerves are present in fish and amphibians. Reptiles and birds also have 12 pairs of cranial nerves.

Share Answer Dimorphic nucleus means two types of nuclei are present in P. caudatum -large macronucleus and small micronucleus. The macronucleus is roughly kidney- shaped and with inconspicuous nuclear membrane. Macronucleus is the somatic or vegetative nucleus and controls the day-to-day metabolic activities of the cell. <br />The micronucleus is lodged in a depression on the surface ofthe macronucleus. It is usually spherical, with a nuclear membrane and with diploid number of chromosomes. It controls the reproductive activities of the organism. Amoeba, Trypanosoma and Plasmodium have only one nucleus.

Share Answer Prawn has one pair of antennae, one on either side, just below the antennules. They are sensory, excretory and balancing in function. Antennules are attached on either side, below the bases of eye stalks. They are tactile in function. Nematocysts are present in cnidoblasts that act as organs of offence and defence. Millipedes belong to class myriapoda. <br />They are called thousand leggers because of possession of numerous walking legs. Body is made up of small head and 40 trunk segments, each with two pairs of jointed legs. Animals belonging to phylum porifera are mostly marine and a few are freshwater.

Share Answer Platyhelminthes do not have body cavity so they are acoelomates. In annelids, the body cavity is true and schizocoelous. Both annelids and platyhelminthes have bilateral symmertry.

Share Answer Protista is the kingdom of unicellular eukaryotes. The protists include heterotrophs, autotrophs, and some organisms that can vary their nutritional mode depending upon environmental conditions. Protists occur in freshwater, saltwater, soil, and as symbionts within other organisms. Trypanosoma, Noctiluca, Monocystis and Giardia are all unicellular protists.