Answer:
Test a known bloodstain as a positive control and a blank (filter paper) as a negative control (see interpretation of results to determine a positive and negative result).
Answer:
plant cells have chloroplasts and a cell wall. (they also have one large central vacuole.)
Explanation: Chloroplasts are found only in plant cells. Chloroplasts convert energy from the sun into sugar (glucose). The chloroplast is also where photosythesis happens in the plant cell. The cell wall is also only found in a plant cell. The cell wall protects and mantains the shape of the cell. And you don't have to put this one but the central vacuole is just one big vacuole in a plant cell that stores mainly water and nutrients since plant cells require more water to function, whereas in animal cells they have multiple small vacuoles.
I believe that the best answer for this question is "gene mutations." Gene mutations can either take place through nucleotide substitutions, which occur when the the sequence of nucleotides are altered. Frameshift mutations can also occur. They involve the insertion or deletion of a DNA molecule's bases. Hope this helps.
They are all part of the digestive system, they all break down food, they all have enzymes
