THE RAT Mammalia (Mammals) - Rat External charateristics The body is divided into a head, neck, trunk and tail and is covered by hair. The rat has two pairs of limbs. Each of the front legs has four toes, each with a claw. Each of the hind legs has five toes, each with a claw. On the head are two ears with pinnae directed to the front. At the front of the head below the …showed first 75 words of 327 total…

…showed last 75 words of 327 total…the oviducts. The zygote develops into the embryo in the uterus of the female. The placenta, an intimate physiological connection between the embryo and the mother, supplies food and respiratory gases and removes wastes and carbon dioxide from the embryo. After a gestation period the young are born alive. Mammals are viviparous. Mammals suckle their young for a while on milk produced by mammary glands of the mother. Mammals show maximum parental care (postnatal care).