The early stage human embryo distinctly possesses
A) Gill
B) Gill slits
C) External ear (pinna)
D) Eyebrows
Answer
277.2k+ views
Hint: Human embryonic development or human embryogenesis refers to the development and formation of the human embryo. In sexually reproducing organisms, embryonic development begins just after fertilization and continues through the formation of body structures, such as tissues and organs.
Complete Answer:
Each embryo starts its development as a zygote which is a single cell resulting from the fusion of gametes. In the first stages of embryonic development, a single-celled zygote undergoes several rapid cell divisions, called cleavage and forms a blastula. Next, the cells in a blastula-stage embryo start rearranging themselves into layers. That process is called gastrulation. These layers each give rise to different parts of the developing multicellular organism, such as the nervous system, connective tissue and organs. Early human embryo possesses a dorsal hollow nerve cord, a well-developed notochord and a series of gill slits to sustain itself in the environment of the womb. These slits are found in embryos of all vertebrates because they share the common ancestry of fish in which these structures first evolved. In humans, they disappear before birth.
Note:
Between the head and the heart, a series of branchial arches, i.e., cartilaginous structures supporting the gills of fishes and larval amphibians, begin to form. In higher vertebrates, these structures form part of the jaw and the ear.
Figure: Gill slits in an embryo
Complete Answer:
Each embryo starts its development as a zygote which is a single cell resulting from the fusion of gametes. In the first stages of embryonic development, a single-celled zygote undergoes several rapid cell divisions, called cleavage and forms a blastula. Next, the cells in a blastula-stage embryo start rearranging themselves into layers. That process is called gastrulation. These layers each give rise to different parts of the developing multicellular organism, such as the nervous system, connective tissue and organs. Early human embryo possesses a dorsal hollow nerve cord, a well-developed notochord and a series of gill slits to sustain itself in the environment of the womb. These slits are found in embryos of all vertebrates because they share the common ancestry of fish in which these structures first evolved. In humans, they disappear before birth.
Note:
Between the head and the heart, a series of branchial arches, i.e., cartilaginous structures supporting the gills of fishes and larval amphibians, begin to form. In higher vertebrates, these structures form part of the jaw and the ear.

Figure: Gill slits in an embryo
Recently Updated Pages
Basicity of sulphurous acid and sulphuric acid are

Which of the following would not be a valid reason class 11 biology CBSE

Why should electric field lines never cross each other class 12 physics CBSE

An electrostatic field line is a continuous curve That class 12 physics CBSE

What are the measures one has to take to prevent contracting class 12 biology CBSE

Suggest some methods to assist infertile couples to class 12 biology CBSE

Trending doubts
The lightest gas is A nitrogen B helium C oxygen D class 11 chemistry CBSE

Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE

Change the following sentences into negative and interrogative class 10 english CBSE

Which place is known as the tea garden of India class 8 social science CBSE

What is pollution? How many types of pollution? Define it

Write a letter to the principal requesting him to grant class 10 english CBSE

Give 10 examples for herbs , shrubs , climbers , creepers

Draw a diagram of a plant cell and label at least eight class 11 biology CBSE
