A control group of the experiment is the one in which no treatment or intervention is given. So, in your case, the pea plants in which was not subjected any of the fertilizers, will serve as a control group. This is a negative control. A positive control group is the one in which an established treatment is given, which definitely leads to the production of the desired character. So, in your case, a very good well-known fertilizer which has a positive control on the growth of the pea plant, would serve as a positive control.
Answer: The correct options are C and E.
Explanation: When the rattlesnake population increases, the population of grasshopper and prairie dog are also decreases.
Both grasshopper and prairie dog are herbivores and eaten by rattlesnake. When rattlesnake population increases they feed on grasshopper and prairie dog and decrease occurs in their population.
Several species of warblers can live in the same spruce tree only because they occupy different nitches within the tree. So option "c" is the correct option as far as the given question is concerned. These birds may not be of the same species but they do have some similarities like they are very vocal and can be rarely seen but definitely heard. All species of warblers are insectivorous and also very small. As they are small so identifying them can be very difficult for a person. These birds are mostly dull greenish or brownish in color.
Answer:
Explanation:
About 2 million fractures occur each year due to osteoporosis. Although all bones can be affected by the disease, the bones of the spine, hip, and wrist are most likely to break.
