Class 11 NEET Biology Animal Kingdom Questions Part 2

(b) : Heart is generally 3 -chambered in reptiles but in crocodile, it is 4-chambered. Sponges are generally marine and have collared cells but few fresh water forms can also be seen like Spongilla. All mammals are viviparous (giving birth to young ones) with an exception, Ornithorhynchus (platypus), which is oviparous (egg laying).