Question

Arrange the following in the ascending order in terms of cell number.
adult, zygote, embryo, foetus​

Answer 1

1)fertilization starts with fusion of male gamete (sperm) and female gamete (zygote).  

2) this fusion results in the formation of zygote.  

3) Zygote divided repeatedly to give rise ball of cells that forms embryo.

4) after the formation of embryo is gets embedded in the wall of uterus where it further forms the foetus so the correct order is in above steps.

Answer 2

Explanation:

On the basis of cell numbers, the ascending order of organism can be determined by understanding the terms used for that particular Organism.

• Zygote - After fertilisation, zygote marks the beginning of a new individual with fused nuclei of male & female gamete.
• Embryo - The zygote undergoes rapid division in teh fallopian tube or the oviduct. They form many protective layers around them and form Embryo.
• Foetus - The Embryo divides and increases the number of cells. Finally these cells start getting a shape of a small foetus that is baby with developed brain, limbs and some internal organs. But it is still inside the womb of the mother$.$
• Adult - After the baby comes out of the womb, he grows into a infant, then a child, and then a teenager. Finally after 18, he or she matures physically and mentally and becomes an adult.

So, the ascending order in terms of cell number:

• Zygote < Embryo < Foetus < Adult

Starting from a single cell, we grew into a mature adult.

And we are done !!

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