Enzymes can be denatured by irregular PH. Meaning that they can change shape. Enzymes rely on their shape in order to function so if their shapes change because of the PH then the active sites don't fit anymore and they enzymes wont work.
Answer:
Meristematic tissue
Explanation:
Meristematic tissue contains actively dividing cells that result in formation of other tissue types (e.g. vascular, dermal or ground tissue). Apical meristematic tissue is found in buds and growing tips of plants.
I would say zygote ® fetus ® embryo ® blastocyst