Final answer:
The question is related to Biology and is at a Middle School level, focusing on plant growth in different environmental conditions and scientific methods in studying plant development.
Step-by-step explanation:
The subject of the question relates to Biology, predominantly focusing on plant development and the factors influencing growth. This is typically a middle school concept, where students learn about the basics of plant biology and scientific experimentation. Dr. Anderson's experiment in planting bean seeds in various temperatures can involve measuring the effects of temperature on seed germination and plant growth. A laboratory experiment studying plant growth might involve controlled setups where variables like temperature, soil type, and water are adjusted to see their impact on the plant's development. Students like Tommy, Tara, and Nick in the scenario are learning about how different soils can affect plant growth.
Factors that may vary and affect plant growth, as described in Gary's experiment, include individual plant variation, soil temperature, water loss, and the effect of insects. Similarly, in the student's detergent experiment, placing pots in the sun versus shade introduces a variable that isn't controlled across all samples. The student's analysis on tobacco seeds also delves into how light exposure can influence plant growth, specifically seedling stem length. Lastly, when investigating the presence of selection at the cellulase locus due to temperature, a biologist is looking into how environmental factors affect genetic expression related to plant development.