Key Concepts: In dicotyledonous leaves there are two types of mesophyll cells, palisade mesophyll and spongy mesophyll. Palisade mesophyll cells form a layer beneath the upper epidermis whereas spongy mesophyll cells are internal to the lower epidermis. major role of leaf mesophyll cells is to contain large populations of chloroplasts, which carry out photosynthetic carbon assimilation facilitating plant growth. Keywords: palisade mesophyll; spongy mesophyll; airspace; bundle sheath; chloroplast. Figure 1.
A ridge or mountain ridge is a geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance. Ridges are usually termed hills or mountains as well, depending on size.
...ridge is a small protuberance just behind the upper front teeth that can easily be felt with the tongue. The major part of the roof of the mouth is formed by the hard palate in the front, and the soft palate or velum at the back. The soft palate is a muscular flap that can be raised so as to shut off the nasal tract and prevent air from going out through the nose. When it is raised so that...