Question

Mammals that give birth to fully developed live young are termed

A. monotremes.
B. marsupials.
C. placentals.
D. bird-like.

Answer 1

C: placentals

Step-by-step explanation:

Mammal is one of the classes of the animal in the phylum chordata. The class consists of animals with basic characteristics such as hairy body, four-chambered heart, mammary glands, and so on. They are divided into two sub-classes;

• Theria
• Prototheria

Theria consists of metatheria and eutheria. While the metatheria includes the marsupials such as kangaroos, eutheria consists of animals with placentals and are often referred to as placental mammals.

The prototherian are often considered as primitive mammals and consists of mammals that lay eggs with ample yolks. They include the monotremes.

Placenta gives placental mammals the capacity to be able nurse their young ones internally till they are fully developed before giving birth to them. The placenta does this by:

• facilitating the attachment of the fetus to the uterine wall of the uterus
• supplying nutrients to nourish developing embryos
• acting as a channel through which toxic wastes from the embryo can be disposed.

The correct answer is C.

Answer 2

Answer: C. placentals.

Step-by-step explanation:

The placentals are the mammals which give birth to a fully developed live young individual. These animals are characterized by the presence of placenta which creates a boundary around the fetus. The transfer of food takes place through the tissues of the placenta. Also the wastes are excreted out through placenta.The placental mammals keep their fetus inside the placenta for a complete period of gestation until the complete physical form of the fetus get developed.