Gas exchange happens in the spongy mesophyll tissue of the leaf. Spongy mesophyll cells are covered by a thin layer of water and loosely packed. When the plant is photosynthesising during the day, these features allow carbon dioxide to diffuse into the spongy mesophyll cells, and oxygen to diffuse out of it.pongy mesophyll cells are covered by a thin layer of water and loosely packed. When the plant is photosynthesising during the day, these features allow carbon dioxide to diffuse into the spongy mesophyll cells, and oxygen to diffuse out of it.
In biometrics and forensic science, minutiae are major features of a fingerprint, using which comparisons of one print with another can be made. Minutiae include: 1  Ridge ending â the abrupt end of a ridge. 2  Ridge bifurcation â a single ridge that divides into two ridges. 3  Short ridge, or independent ridge â a ridge that commences, travels a short distance and then ends.
Bits used come in a variety of types but the more commonly used Ridgeway- and Irwin- pattern bits also rely on a snail point (called the snail), which is a tapered screw point shaped the same as a wood screw thread, which helps to pull the bit into the wood as the user turns the brace handle and applies pressure