The cause could be genetic, fungal or something else. It would be best to check in with a dermatologist.
down the middle
down the middle
right down the middle
Down the middle.
The stage at which a DNA molecule is split down the middle is replication. The first step in making a protein is RNA copying DNA.
2nd
1965
The enzyme helicase splits it down the middle by breaking the hydrogen bonds.
sometimes when you have a split down the middle of your toungue, its from eating many sour items,
split it down the middle
cross-section
vertical split bar