Growth and development of multi cellular organisms
- The normal growth and development in all multicellular organisms occur in a programmed manner.
- The new born babies have no teeth, teeth formation starts from 4th or 5th month.
- For example when a seed germinates it produces roots first and after sometime it gives branches, flowers and fruits.
- All the plants do not give flower all times.
- Some plants complete their life cycle in few months and some plants take more than 6 months and some other have different duration of flowering.
- It must be interesting to note that these changes in the plants or animals in different stages of the life cycle occur as if some instructions are given to these organisms from time to time.
- There is a set of genetic programmes which is operated to carry out specific functions at specific time in the life cycle of living organisms.