1. Major scientific theories include the cell theory, the big bang theory, and the theory of plate tectonics. How are scientific theories formed?

- Through meetings between scientists in which they discuss several possible answers to a scientific question
- Through extensive testing and the accumulation of several lines of evidence
- Through a single scientific discovery in which a scientist learns something new
- Through the formation of several related hypotheses

2. Kristan has an outdoor garden where she grows geraniums. One day, she decides to try to grow a geranium inside her house. After a month, she notices that the plant has grown more than those that are outdoors. Kristan begins to wonder why her indoor geranium has grown more than those outdoors. She takes some observations outdoors and indoors and notices that there are differences in humidity, temperature, and light. Based on her observations, Kristan asks the question, "Do temperature variations affect how much geraniums grow?" Which of the following hypotheses might Kristan make to help answer this question?

A. Geraniums like to be near people.
B. Why does temperature affect the growth of geraniums?
C. Geraniums grow better in fresh air.
D. Geraniums grow more when temperatures are nearly constant.

Scientific theories are formed through extensive testing and the accumulation of several lines of evidence. A scientific theory is a well-substantiated explanation of some aspect of the natural world that is based on a body of facts that have been repeatedly confirmed through observation and experiment. The process involves many scientists working over time to gather evidence, test hypotheses, and refine their ideas based on new information. It's not typically the result of a single discovery or just forming hypotheses, but rather a comprehensive understanding built over time. Therefore, the correct choice is: through extensive testing and the accumulation of several lines of evidence.
Kristan observes differences in growth between her indoor and outdoor geraniums and starts to wonder if temperature affects how much they grow. A good hypothesis should be a statement that can be tested through experiments or observations. Kristan's question about temperature can be addressed with the hypothesis: Geraniums grow more when temperatures are nearly constant. This hypothesis is a testable statement that proposes a potential explanation for the observed difference in growth and can be tested by controlling temperature conditions for the plants.