Teaching OSSSC TGT Teachers Mock Test Series 2025 Biology Diversity in The Living World Animal Kingdom
Which is characteristic of all mammals, and only of mammals?
1
a four-chambered heart that prevents mixing of oxygenated and deoxygenated blood.
2
giving birth to live young (viviparous).
3
parental care of offspring.
4
having glands to produce nourishing milk for offspring