Aunique characteristic of mammals is that they

a.) have hair
b.) have a four-chambered heart
c.) have both aquatic and terrestrial species

The correct answer for the blank is- A) Have hairs.

As per the University of Michigan, there are primarily three characteristics/ features that are unique to mammals. These are as follows-

1) Presence of hairs on body.

2) Presence of mammary glands ( primarily used of feeding the neonates).

3) Presence of three bones in the middle ear ( that is Malleus, incus, and stapes).

The most significant function of hairs in mammals is that they provide insulation against cold by conserving heat of body. In certain nocturnal animals ( which are active during night time), they serve as sensory organs.

Thus, option A) is the right answer.

other information encoded in your genes might distinguish you from the others in the group

answer; blank(1); cervical; blank(2); lumbosacral;