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 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.
In an animal cell, it is the cell membrane and in a plant cell, it is the cell wall.
Active cell.
IT is a hustle . Or many people call IT " the dark night"
Dark cells
the nucleus.
the cellis called the judgular vasictomy cell
Active cell.
dark cell, dungeon
Nucleolus
i have a sex to my husband twice, and i am wondering his sperm cell is dark brown, at first my thought is my period, but is not, can you tell me what is all about