After conception, your baby begins a period of dramatic change known as the embryonic stage. This stage runs from the 5th through the 10th week of pregnancy . During this stage, the baby is called an embryo. There are numerous changes that occur during the embryonic stage.
What is the first embryonic stage?
The cleavage and blastula stage
The initial growth stages of multi-cellular organisms start with a zygote cell, which then undergoes fast cell division to form the initial cell cluster, or ‘blastula’. This rapid division of cells is known as the process of ‘cleavage’.
What happens during pre-embryonic period?
1 – Pre-Embryonic Cleavages: Pre-embryonic cleavages make use of the abundant cytoplasm of the conceptus as the cells rapidly divide without changing the total volume . As the blastocyst forms, the trophoblast excretes enzymes that begin to degrade the zona pellucida.
How long does the embryonic period last?
The Embryonic Period
It lasts from the third through the eighth week after conception . During this period, cells continue to differentiate and at 22 days after conception the neural tube forms which will become the brain and spinal column.
What happens embryonic development?
In developmental biology, embryonic development, also known as embryogenesis, is the development of an animal or plant embryo . Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm cell, (spermatozoon). Once fertilized, the ovum becomes a single diploid cell known as a zygote.
What are the 3 stages of pregnancy?
- First Trimester (0 to 13 Weeks) The first trimester is the most crucial to your baby’s development. ...
- Second Trimester (14 to 26 Weeks) ...
- Third Trimester (27 to 40 Weeks)
What are the four stages of embryonic development?
- Germinal stage. 1.1 Fertilization. 1.2 Cleavage. 1.3 Blastulation. 1.4 Implantation. 1.5 Embryonic disc.
- Gastrulation.
- Neurulation.
- Development of organs and organ systems.
What is the final stage of embryo?
By the twelfth week of fertilization the embryo moves into the final stage of development called the fetal stage . By now, the fetus has formed all of the organs and structures necessary for a baby, but those organs still need to grow and develop.
What organs form first in an embryo?
The heart is the first organ to form during development of the body. When an embryo is made up of only a very few cells, each cell can get the nutrients it needs directly from its surroundings.
What is the correct order of embryonic development?
Hence the correct answer is ‘C’ i.e, Zygote-morula-blastula-gastrula-embryo . Note:All cleavage divisions are mitotic and resultant daughter cells are blastomeres.
Why is the embryonic period the most critical?
The embryonic period is the most critical period of development because of the formation of internal and external structures . The critical periods of development for the organs are also discussed in the section on specific organ development.
Is an embryo a baby?
An embryo is the early stage of human development in which organs are critical body structures are formed. An embryo is termed a fetus beginning in the 11th week of pregnancy, which is the 9th week of development after fertilization of the egg. A zygote is a single-celled organism resulting from a fertilized egg.
Is a zygote a baby?
When the single sperm enters the egg, conception occurs. The combined sperm and egg is called a zygote. The zygote contains all of the genetic information (DNA) needed to become a baby. Half the DNA comes from the mother’s egg and half from the father’s sperm.
What is meant by embryonic?
1 : of or relating to an embryo . 2 : being in an early stage of development : incipient, rudimentary an embryonic plan.
What is embryonic evidence?
The study of one type of evidence of evolution is called embryology, the study of embryos . ... Many traits of one type of animal appear in the embryo of another type of animal. For example, fish embryos and human embryos both have gill slits. In fish they develop into gills, but in humans they disappear before birth.
How does a human embryo develop?
During fertilization, the sperm and egg unite in one of the fallopian tubes to form a zygote. Then the zygote travels down the fallopian tube, where it becomes a morula. Once it reaches the uterus, the morula becomes a blastocyst. The blastocyst then burrows into the uterine lining — a process called implantation.
