Embryonic stem cells (ESCs) are derived from embryos when they are in the blastocyst stage, which occurs about
(a) 5 days (b) 5 weeks (c) 5 months following conception.
Adv.
Embryonic Stem Cells (ESCs) are derived from embryos when they are in the blastocyst stage, which occurs about 5 days.
Stem cells are types of cells which have the ability to develop into numerous cells, similar to itself and also a type of specialized cells. It is important to note that numerous varieties of stem cells get developed in various phases of life. Embryonic stem cells are types of stem cells that occur naturally in early period of human life. Embryonic stem cells, as their name, occur in the developing embryo. A fertilized egg developed when the nucleus of sperm fuses with the nucleus of the egg cell. The fertilized egg cell is called as zygote, which develops into an embryo. Formation of blastocyst occurs on the fifth day from first division. A hollow, fluid filled ball, which consists of to cells, approximately is termed as blastocyst. Blastocyst develops into two main types of cells, placenta and inner cell mass. The inner cell mass is composed of embryonic stem cells, which has the ability to differentiate into any type of cell in human body.
Hence, the correct option is (a) 5 days.
The development of organs initiates in the developing embryo during four to five weeks of fetal development. The embryonic stem cells do not occur in this phase. The inner cell mass of the blastocyst is composed of embryonic stem cells. The blastocyst develops on the fifth day after fertilization.
Hence, the option (b) is incorrect
Approximately weeks following fertilization, the embryo develops into a fetus. Also, embryonic stem cells occur only in blastocyst stage, which occurs in about days after fertilization. Five months, following conception, some fetal organs get completely developed. However, embryonic stem cells do not occur in this stage.
Hence, the option (c) is incorrect.