grain of rice
Refers to a single grain of uncooked or cooked rice. Common in everyday contexts.
A grain of rice is stuck to the rice bowl.
Eat every last grain of rice.
I found a tiny bug about the size of a grain of rice.
You have a grain of rice stuck on your cheek.
粒 is a generic word/counter for any small round object, whereas 米粒 specifically names a grain of rice.
grain; bead; drop · counter for small round objects
lesser hop trefoil; suckling clover
black medic; black hay; black nonsuch; blackweed
Compound of 米 (こめ, rice) and 粒 (つぶ, grain). The reading is a straightforward combination of the kun'yomi readings of each kanji.