Question

The fertilized egg is known as

Answer 1

Answer: Zygote.

Zygote is the first product of fertilization. That is, when the haploid sperm (male gamete) fuses with (fertilizes) the haploid egg (female gamete), a new cell called zygote (diploid) is formed inside the female reproductive system. Zygote is also called as fertilized egg. Zygote has cell division at much higher speed compared to normal somatic cells. Embryo is usually formed about 12 – 16 days after fertilization (i.e., after zygote formation ). In humans, the zygote rests in the fallopian tube for upto 5 days. Then, it slowly starts to move in to the uterus.
It may be noted that, it is not the two cells viz. Sperm and egg that fuses. In fact, it is the nucleus of sperm and nucleus of egg that fuses. The integrity of structural components of the egg as a cell is not affected by fertilization, except for a change in ploidy level of the nucleus. The nuclear component of the zygote is shared by both male and female gametes, but the cytoplasm completely belongs to the egg. It is for that reason, the inheritance of characters through the cytoplasmic genome viz. Mitochondrial DNA ( Mitochondrial and Chloroplast DNA in plants) is termed as maternal inheritance. (Inherited from the mother).