Differentiate between Foetus and Zygote.
Hint:
Zygote and fetus are terms used to describe different stages of development within the mother’s womb. The zygote is the earliest stage of development, formed when the sperm and egg cells unite, resulting in a fertilized ovum. The fetus, on the other hand, represents the later, more advanced stage in the baby’s growth, occurring after the zygote has developed further.
Complete answer:
The zygote and fetus are distinct stages in human development. Here are the various stages of this process:
Zygotic Stage: This is the first stage, where a zygote is formed when the male sperm and female egg combine within the female body.
Blastocyst Stage: Following the zygotic stage, the zygote undergoes division, developing into a solid ball of cells known as a blastocyst.
Embryonic Stage: In this third stage, the embryo forms, and internal organs like the brain, heart, and spinal cord begin to develop. External features such as arms and legs also start to appear.
Fetal Stage: After the embryo has formed, the developing organism enters the fetal stage, where it continues to grow and mature.
| Zygote |
Foetus |
| A zygote is created when the sperm and egg nuclei merge. | The fetus is the stage in development where the embryo closely resembles a human being. |
| It is a single cell structure. | It is made up of many cells. |
| This stage follows fertilization. | The fetal stage follows cell division and differentiation. |
| In the zygote stage, the body structure is not yet formed. | In the fetus stage, distinct body parts and features are developed. |
Note:
A zygote is a fertilized egg that forms when the sperm and egg combine. It goes through several divisions to transform into an embryo. In contrast, the fetus is a later stage of the embryo, where the primary body parts of a fully developed organism are clearly visible.