An independent variable is the variable that is changed. A dependant variable is the variable that is measured. And the control refers to all the other variables that need to be controlled in the experiment.
For example, if you were to conduct an experiment to see how quickly different amounts of water boiled; the independent variable would be the amount of water, the dependant variable would be the time it took to bail and the controlled variables would be the type of water, the temperature and type of heat source, etc.
Answer:
Weathering and erosion constantly change the rocky landscape of Earth. Weathering wears away exposed surfaces over time. The length of exposure often contributes to how vulnerable a rock is to weathering. Rocks, such as lavas, that are quickly buried beneath other rocks are less vulnerable to weathering and erosion than rocks that are exposed to agents such as wind and water.
Explanation:
Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. Once a rock has been broken down, a process called erosion transports the bits of rock and mineral away. No rock on Earth is hard enough to resist the forces of weathering and erosion. Together, these processes carved landmarks such as the Grand Canyon, in the U.S. state of Arizona. This massive canyon is 446 kilometers (277 miles) long, as much as 29 kilometers (18 miles) wide, and 1,600 meters (1 mile) deep.
The blob operon produces enzymes that convert compound A into compound B. The operon is controlled by regulatory gene S. Normally, the enzymes encoded by the operon are synthesized only in the absence of compound B. If gene S is mutated, the enzymes are synthesized in the both the presence AND absence of compound B. Gene S must encode a(n):
a. inducer.
Answer:
Thiamine pyrophosphate (derived from vitamin B1) is a coenzyme required for the activity of pyruvate dehydrogenase enzyme complex.
Explanation:
Pyruvate is the end product of glycolysis. During aerobic cellular respiration, pyruvate is oxidatively decarboxylated into acetyl CoA which in turn enters the Kreb's cycle. Oxidative decarboxylation of pyruvate is carried out by enzyme complex pyruvate dehydrogenase (PDH). The first step is simple decarboxylation and is catalyzed by pyruvate decarboxylase of the PDH complex.
The enzyme pyruvate decarboxylase and has a tightly bound coenzyme, thiamine pyrophosphate. Thiamine pyrophosphate is derived from vitamin B1. Lack of vitamin B1 in the human diet leads to beriberi that is characterized by an increased concentration of pyruvate in blood urine since oxidative decarboxylation cannot occur due to lack of the coenzyme thiamine pyrophosphate.
Food moves through the digestive system tract by peristalsis, which is produced by wavelike contractions of INVOLUNTARY muscles