Crusts and uppermost mantle
Sand is granular and coarse meaning that water and nutrients can flow through it quite easily. Clay on the other hand has very fine particles that cling together to form a waterproof substance which traps/ stops any nutrients or water from moving down. Clay's also quite difficult for plants to get their roots into. Silt has a texture between clay and sand, meaning that it is the ideal substance as it allows the best water and nutrition movement in the soil. Most plants will grow best in silt, but there are some plants who are more adapted to living in sand (e.g. Marram grass) or clay.
Answer: B. In hypoxic tissues, in contrast to normoxic tissues, ATP is additionally consumed to transform lactate to pyruvate
Explanation:
In hypoxic tissues such as new cancerous cells, the vascular system is still underdeveloped, thus oxygen supply is reduced. To meet energy need, additional glucose is needed to convert lactate (result of anaerobic glycolysis) to pyruvate which can then go into the TCA cycle to yield energy. This phenomenon is very common in muscle tissues during exercise.
There are often not more than one or two independent variables tested in an experiment, otherwise it is difficult to determine the influence of each upon the final results. There may be several dependent variables, because manipulating the independent variable can influence many different things.
