It could just be a cell with a border around it, or it could be the active cell, which is probably the answer you are looking for.
If it is the standard one that surrounds all cells, it is a gridline. If it is heavier and made to have the cell stand out, it would be a border.
The dark outline of a cell is typically referred to as the cell membrane or plasma membrane. This structure surrounds the cell and acts as a barrier, regulating the movement of substances in and out of the cell.
Active cell.
IT is a hustle . Or many people call IT " the dark night"
the nucleus.
the cellis called the judgular vasictomy cell
The dark center of a frog blood cell is the cell nucleus, which contains genetic material such as DNA. The nucleus is responsible for controlling cell activities and regulating gene expression.
Active cell.
Nucleolus
dark cell, dungeon
The nucleus is the largest organelle of the cell. It is a dense body containing chromosomes, surrounded by a nuclear membrane. The nucleus can be seen as a dark oval shape under a light microscope.
Dense and dark