Answer:
Due to small in size.
Step-by-step explanation:
Some organelles such as nucleus, mitochondria and Golgi bodies can't be seen because they are too small in size and near to the limit of the microscope. Organelles present in plant cell are nucleus, mitochondria and Golgi, endoplasmic reticulum, ribosomes, one big vacuole, cell membrane and cell wall whereas organelles present in animal cell such as nucleus, mitochondria and Golgi bodies, endoplasmic reticulum, ribosomes, lysosomes, several small vacuoles and cell membrane. In animal cell centriole and lysosomes are present and absent in plant cell while in plant cell, cell wall and one large vacuole present in the center of the nucleus and these organelles are absent in animal cell. Plant and animal cells are eukaryotic because they have organelles and surrounded by membrane.