Question

match with the best description
ectoderm
mesoderm
placenta
embryo
blastocyst
cleavage

Answer 1

Ans:-

Match of the given terms with their best description is as follows:-

- Ectoderm:- Ectoderm is a one of the three germ layers. It is outermost layer of the cells or tissue of an embryo in early development.

In vertebrates it gives rise to skin , hair, nails, lens of the eye, lining of the nasal cavity , sinuses, mouth, anal canal. It forms nervous system (spine, peripheral nerves and brain), tooth enamel and epidermis.

- Mesoderm:- It is also one of three germ layers in the early embryo. Mesoderm is the middle layer out of three germ layers; ectoderm, mesoderm and endoderm.

Mesoderm forms skeletal system, muscular system, excretory system, circulatory system,reproductive system and lymphatic system.

- Placenta:- Placenta is an organ that develops in the uterus during pregnancy.

Placenta provides oxygen and nutrients to the growing baby and removes waste from the baby's blood through umbilical cord.

Placenta is attached to the wall of the uterus of the mother and from it umbilical cord arises that connects baby to the mother.

- Embryo:- Embryo is an early stage of development of a multicellular organism.

After fertilization from 2nd week to the 8th week of the pregnancy the product of conception is called embryo.

- Blastocyst:- It is a structure formed in the early development of the mammals.

It possesses an inner cell mass which subsequently forms embryo and the outer layer of the blastocyst consists of cells collectively called trophobalst.

It is the developmental stage prior to the implantation of the embryo in the mother's uterus.

- Cleavage:- It is the division of the cells in the early embryo .

The different cells derived from the cleavage are called blastomeres and these blastomeres form a compact mass called the morula.

Cleavage ends with the formation of the blastula.