NTA Abhyas NEET2020BotanyAnimal KingdomPractice
Which one of the following categories of animals, is correctly described with no single exception in it?
Options
- AAll reptiles possess scales, have a three-chambered heart and are poikilothermal.
- BAll bony fishes have four pairs of gills and an operculum on each side.
- CAll sponges are marine and have collared cells.
- DAll mammals are viviparous and possess diaphragm for breathing.
Correct answer
B. All bony fishes have four pairs of gills and an operculum on each side.
Step-by-step solution
A All reptiles possess scales and are poikilothermal. They have a three chambered heart EXCEPT Crocodile, which has a four-chambered heart. B Bony fishes belong to the Class Osteicthyes of Phylum Chordata. All fishes belonging to this class have four pair of gills and an operculum on each side. There is no exception in them. C Sponges belong to the Phylum Porifera. They have collared cells known as chanocytes. Sponges are generally marine but some of them may even be found in fresh water. Eg: Spongilla is a fresh w