Compared to arteries, valves have no pulse, have thin walls and have valves that prevent backflow of the blood. The pressure in the veins is less than that of the arteries, hence, there is no pulse. They are nearer to the surface of the skin. It also connects arteries and capillaries which transport blood all throughout the circulatory system.
Answer:
An experimental group is a group that receives the variable being tested in an experiment. The control group is the group in an experiment that does not receive the variable you are testing.
Explanation:
Control group, the standard to which comparisons are made in an experiment. ... A typical use of a control group is in an experiment in which the effect of a treatment is unknown and comparisons between the control group and the experimental group are used to measure the effect of the treatment.
The control group would be the group you keep control as you would not change anything about it throughout the course of the experiment. The experimental group you would give the experimental drug to.
Answer:
The answer is C.
Explanation:
Net Primary Productivity is a term that is used to express the difference between CO2 that is taken in by the plant with photosynthesis minus CO2 that the plant releases.
The two forest sites given in the example may not have the same biodiversity and the same species of plants so we can't be sure of option B.
Again for the same reasons, we can't be sure of option D because we do not know the specific plant species in each forest since they are in different areas.
Option A can be ruled out for the same reasons, the lack of information about the forest sites, since we do not know the death rate of the plants in either of the forests.
Option C can be true because forest A has a higher net primary productivity rate which can be an indication of lower respiratory activity hence lower CO2 production, resulting in the given higher net primary productivity.
I hope this answer helps.
If you are referring to selection pressure, when the selection pressure decreases, there will be weaker forces of natural selection. The angler fishes without the favourable traits would not be that strongly selected against and vice versa. In some cases such as predation selection pressure, the population of angler fishes in the habitat may increase
Enzymes are biological catalysts. Catalysts work by lowering the amount of energy required to set off a chemical reaction.