These humans that you speak of belong to the placental group of mammals
yes
No, humans are mammals and evolved from other primitive mammals.
No, not all mammals are placental. There are two other groups of mammals: the monotremes and the marsupials.Monotremes are egg-laying mammals, and marsupials are generally pouched mammals, although not all marsupials have fully developed pouches.
Humans and all other primates share a common mammalian ancestor from millions of years ago, a possum-like tree mammals. Mammals diversified to adapt to the different conditions they were faced with, becoming all the groups of mammals we see today.
because they have similar properties to the other elements in their groups
None.
Like all the other weevils, the giraffe weevil is a beetle, and thus, belongs to the class Hexapoda.
Bird and mammals are the only two groups of vertebrates which are warm blooded. Amphibians, reptiles and fish, the other vertebrate groups, are all cold-blooded.
Rodents have backbones, like all mammals. All animals with backbones belong to the phylum Chordata. Other animals that belong to Chordata besides mammals include reptiles, birds, amphibians, and three classes of fish.
Early humans lived in groups for protection, hunting, gathering food, and sharing resources. Living in groups increased their chances of survival in a harsh environment. By collaborating and working together, they were able to defend against predators, find food more efficiently, and care for each other.
Humans have 24 (12 pair). Other mammals may have more or less.
Marine mammals live and water and they need to surface to breathe. While land mammals can breathe just as humans do.