Answer:
Water sample showing pink/purple color is an error.
Explanation:
Biuret is a blue color reagent that changes its color to pink/purple whenever it detects protein in a sample. Water don't contain proteins so it should not show pink/purple color instead it should maintain the blue color. Food items generally contain proteins so it show pink/purple color but it showed blue color.
Error might have caused by wrong marking of the samples, test tube marked with Water might contain a mystery food while Mystery food tube might contain water.
The study of onion root tips is widely known for the clear appearance of the stages of mitosis since the chromosomes are large and are clearly visible. They are easily stained with the stainer and are visible clearly under the electron microscope. The phase of mitosis are
Interphase
Prophase
Metaphase
Anaphase
Telophase and
Cytokinesis
Each of these phases show the different stages in which the division of one cell into two daughter cells takes place. The cytokinesis is the final phase in the mitosis cell division. This is the part of cell division process during which the cytoplasm of the cell divides into two equal parts and forms into two daughter cells.
During the cytokinesis process, the spindle apparatus partitions and transports the duplicated chromatids and moves into the cytoplasm of the dividing daughter cells. In this process a dividing structure called the cell plate is formed to distinguish the daughter cells. This cell plate later grows into a double layered cell wall which then splits the parent cell into two separate cells.
Hence the option D is the right answer
<span>Independent variable: Time plants are watered (ex. 8am, 12pm, 4pm, 8pm, 12am)
Dependent variable: growth of the plant
Controlled variable: 1. same type plants, 2. same amount of sunlight, 3. same type of dirt, 4. same type of water, 5. same amount of water (each are self explanatory of how to control)</span>
