The transition directly from a solid to a gas
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.
The main difference between aerobic respiration and anaerobic respiration is that aerobic using oxygen in the reaction, while anaerobic does not.
Even though both aerobic and anaerobic respiration releases energy, but their reactants and other products are completely different.
For example in human, in aerobic respiration, oxygen and glucose reacts to give out carbon dioxide and water; while in anaerobic respiration, which usually happens during exercise when oxygen is not enough, the muscle cells uses only glucose to produce energy and lactic acid.
Therefore, the main difference is where aerobic uses oxygen, and anaerobic don’t.
Answer:
B. the combination of modern genetics and Darwinism.
Explanation:
The modern synthesis refers to the concept which combined the theory of inheritance by Mendel and theory of evolution by Charles Darwin. The theory also used the concept of Theory of germplasm.
The modern synthesis concept came in the early 20th century when the studies were going on Mendel's theory and the evolutionary aspects. The concept led to the formation of new concepts like the macroevolution, microevolution and the evolution affected by mutation of genes.
Thus, Option-B is correct.
