Question

Mammalian blastula is known as
A. Trophoderm
B. Blastocyst
C. Foetal blastula
D. Oedema

Answer 1

The blastula is a hollow sphere of cell surrounding an inner fluid- filled cavity. It is formed during an early stage of embryonic development in mammals.

Complete step by step answer:
To solve this question we must know about the mammalian blastula.
Blastula is a spherical layer of cells called the blastoderm and is surrounded by a fluid filled cavity called the blastocoel. In mammalian reproduction, the male sperm fertilises with the female egg and forms a zygote. The zygote undergoes many cleavages and forms a ball-like structure that is called morula. After the formation of blastocoel, the early embryo becomes a blastula. In mammals the blastula is referred to as blastocyst.
In mammalian blastocyst there are three lineages- The epiblast gives rise to fetus, the trophoblast develops into placenta and primitive endoderm becomes yolk sac.
Trophoderm- It is the outer layer of blastocyte.
Oedema- It is the term used for fluid retention in the body. It is also called swelling.

The correct answer is (B). Mammalian blastula is called blastocyst.

Additional Information: Blastocyst serves as an important tool during in vitro fertilisation. In in-vitro fertilisation it involves implantation of a blastula into a mother’s uterus. The blastula cell implantation helps to eliminate infertility.

Note:
The blastocoel has components which are necessary for cellular differentiation. It contains amino acids, proteins, growth factors, sugars, ions. The blastula is formed before gastrula in which the germ layers of the embryo form.