Activity Many farmers and gardeners compost their plant and animal waste. The living material naturally decays in compost bins,
forming a dirt-like substance that’s rich in nutrients. The next season, farmers use this substance as a natural fertilizer for their crops. A biology student has grown tomato plants for several years. Until now, he used an artificial fertilizer formulated for tomato plants. This fertilizer caused his plants to grow faster and taller than they grew in unfertilized soil. The student wants to know whether using natural compost will cause his tomato plants to grow faster and taller than his artificial fertilizer. Answer the following questions to plan an investigation using the steps of the scientific method and help the student find the answer to his question. Part A What are the student’s observations and inferences before he starts his investigation?
The scientific method is a research method used to produce knowledge. It consists of systematic observations, measures, experimentation, analysis, and verification of a hypothesis. It is based on two aspects: reproducibility (the capability of reproducing the experiment in any other place by any researcher) and refutability (susceptibility to be refused). The steps of the scientific method are Previous knowledge about the study object. A question the investigator wants to answer. The goal, which is what the investigator wants to know. The hypothesis that the investigator makes in order to predict what is going to happen. The experiment is performed to answer the question. Results obtention. Discussion and Conclusions where the hypothesis is rejected or accepted.
Definition and problem statement. The question for which there is not an answer yet.
Objectives, Hypothesis, and Predictions formulation
Data collection and analysis. This step involves testing the observations.
Results
Verification of hypothesis. This step involves the deriving of the working hypothesis.
Discussion and Conclution.
About the exposed investigation, the student’s observations and inferences before he starts his investigation are the following:
Question: For example, How do tomato plants respond to each fertilizer?. Will the tomato plants grow faster when natural compost is used or when artificial fertilizer is used?
Previous knowledge: The student should know the optimal conditions required by tomato plants´ to grow better. What elements, nutrients, and compounds each fertilizer provides, and their characteristics. Antecedents of each treatment employed in the same or similar species.
Objective/Goal: What the researcher wants to know or find out. An example could be: To analyze whether using natural compost or artificial fertilizer will cause his tomato plants to grow faster and taller.
Hypothesis: It must express what is expected to occur, according to the antecedents and previous knowledge. It must be expressed in a perfectly comprehensive manner. There must be a logical relation between variables. It must be objective. An example could be: By the employment of artificial fertilizers, the plants will grow faster and taller.
Predictions: These are different possible explanations to what is expected to occur. They are anticipations of what is going to happen. But these are not necessarily correct. For example, An artificial fertilizer will apport exactly what the plants need to grow faster and taller, while natural fertilizer provides different nutrients in different amounts.
The student has observed that artificial fertilizer makes his plants grow faster and taller than plain soil. He knows that compost is a natural fertilizer. So, he infers that compost will make his plants grow at a faster rate than they grow in plain soil.
Saliva contains special enzymes that help digest the starches in your food. An enzyme called amylase breaks down starches (complex carbohydrates) into sugars, which your body can more easily absorb. Saliva also contains an enzyme called lingual lipase, which breaks down fats.
