fetus
organ system
Uterus
your answer is sperm
The only organ fully developed at birth in the human body is the brain.
eyes
Organ
smell
Tissue is a group of cells which have a special job to do whilst an organ is formed by a group of tissues with a special job. When you have a group of organs, you have an organ system.
i think the first organ that formed in frog and chick are started at the gastrulation where 3 germ layers are formed first. mesoderm, ectoderm and endoderm. the layer then will differentiate into specific organ such as nerve system, epidermis or etc.
Before birth
Germ layer development in embryos begins with gastrulation, the process by which a blastula reorganizes into a gastrula with distinct germ layers (ectoderm, mesoderm, and endoderm). During gastrulation, cells migrate and differentiate to form these primary germ layers, setting the foundation for future tissue and organ development.
The womb is an organ in the human body. It is the part of the female's body where a baby is formed.