The answer is negative controls. These are groups where no phenomenon is probable. They ensure that there is no effect when there should be no effect. Where there are only two possible outcomes, e.g. positive or negative, if the treatment group and the negative control both produce a negative result, it can be concluded that the treatment had no effect. If the negative control group and the treatment group both yield a positive result, it can be inferred that a puzzling variable is involved in the occurrence under study, and the positive results are not only due to the treatment. In other examples, outcomes might be measured as lengths, times, percentages, and so forth.
Answer:
Explanation:
Xylem transports and stores water and water-soluble nutrients in vascular plants.
Phloem is responsible for transporting sugars, proteins, and other organic molecules in plants.
Vascular plants are able to grow higher than other plants due to the rigidity of xylem cells, which support the plant.
Answer: C). Sensory neurons, D).motor neurons
Explanation: Sensory neurons are nerve cells that carry signals from the external parts of the body such as the skin, eyes, ear, nose (the sense organs) to the brain.
Motor neurons are nerve cells that carry information or messages away from the central nervous system ( brain and spinal cord) to the rest of the body such as the skin, muscles and glands.
Answer:
Repetitive DNA segments: transposable elements.
I hope it helps.
