Answer:
A. It contains fewer volatile gases.
Explanation:
Mafic lava have a composition of about 45-55% silica with high amount of Fe, Mg, Ca.
The silica content is quite low compared to those of granitic magma whose silica content can reach up to about 60%.
What determines the viscosity of magma is basically the silica content of the magma and the temperature of the magma. Viscosity is the resistance to flow.
The higher the silica content, the lower the viscosity and the higher the amount of volatile gases. Such type of magma is the granitic magma. Granitic magma due to their viscosity flows slowly.
The lower the silica content, the higher the viscosity and the lesser the presence of volatile gases in them. Such an example is Mafic magma. Mafic magma flows very slowly with low amount of dissolved gases.
c. Light independent reactions
Answer:
They have helical thickening of lignin in their walls to prevent collapse
Explanation:
the primary function of Xylem and its conducting vessels tracheids is to provide support and tranport water and minerals in plants.
Xylem vessels have layers of dead materials in the walls called LIGNIN. Lignin is a polymer; a very strong, hard materials that stop water passage through it,because it contains dead cells,
Therefore the presence of deposit of these strong impermeable, ligified walls in its walls prevent its collapse during mass flow of water of transpiration pull.
