The answer might be cytoplasm
Answer:
The correct answer is option (D) "His- strain grows on an his- plate".
Explanation:
The Ames test is a procedure that allows to detect if a given compound can cause mutations on a tested organism by growing strains of bacteria that require histidine (His-) to growth, since they are not able to produce its own histidine. In the Ames test, the bacteria is exposed to a given compound and is grown in a medium with small amount of histidine (his- plate). If the His- strain grows on a his- plate, it means that the bacteria has mutated to synthesize its own histidine and it is considered as a positive result on a the Ames test.
1. Answer: to answer questions about the natural world
The aim of scientific method is to answer a question that the scientist have. To answer the question, the scientist need to design a research or observation. If the research is flawed, the result might not match with the scientist aim and the conclusion will be wrong. Scientific method can be used to help design the research so it will have less flaw
2. Answer: fertilizer
The student wants to determine the effect of a certain brand of liquid fertilizer on the growth of ivy. The fertilizer are hoped to influence the growth of the ivy. Independent variable is the variable that hoped to influence the dependent variable. So, the independent variable would be fertilizer and the dependent variable would be the growth.