Which shows the stages of fetal development in the correct order
The correct order of the stages of fetal development is as follows:
1. Fertilization: The process starts with the union of a sperm cell with an egg cell, forming a single cell called a zygote.
2. Cleavage: The zygote undergoes multiple rounds of cell division, known as cleavage, resulting in the formation of a solid ball of cells called a morula.
3. Blastulation: The morula then develops into a hollow ball of cells called a blastula.
4. Implantation: The blastula implants itself into the wall of the uterus, establishing a connection with the maternal blood supply.
5. Gastrulation: The blastula undergoes a process called gastrulation, during which the cells differentiate and rearrange themselves into three primary germ layers: ectoderm, endoderm, and mesoderm.
6. Organogenesis: The three germ layers give rise to different organs and tissues. Organogenesis occurs during this stage, and major organs and body systems begin to form.
7. Fetal period: From the 9th week onwards, the developing organism is considered a fetus. During this period, the fetus continues to grow and mature, with organ systems becoming more developed and functional.
It's important to note that this is a simplified version of fetal development, and different sources may provide slightly different details or additional subdivisions within these stages.