Objective To investigate the relationship between the first polar body morphology of oocyte and the zygote morphology in pronucleus stage, embryo quality in cleavage stage.
On the inside, the fallopian tubes have smooth muscle with an inner lining that has ciliated cells that slowly sweep the secondary oocyte or zygote towards the uterus.
This specialization makes DNA from non-sex cells particularly unsuited for cloning purposes because those tags and tangles make it hard for the clone zygote to divide.
First, they all start as single-celled zygotes — made from a sperm cell and egg cell combo — that become multicellular embryos: the tiny beginnings of roots, stems, and leaves.
Once the sperm arrives, it fuses with the egg to make a zygote — a cell that contains all the DNA needed to make a baby, thanks to the combination of the two DNA halves.
一旦精子到达,它就会与卵子融合,形成受精卵——由于两半 DNA 结合,受精卵包含了制造婴儿所需所有 DNA。
Cloned zygotes are not reliable because while all other cells in the body do contain a full set of DNA, these other cells optimize their DNA to best serve their own particular functions.
克隆受精卵并不可靠,因为虽然体内所有其他胞确实含有全套 DNA,但这些其他胞会优化其 DNA 以最好地发挥其自身特定功能。
Because the clone zygote contains a full set of DNA just like the regular zygote does, you might expect it to DIVIDE AND turn into an embryo just like a regular zygote does too...