Biology Chapter 1: The Study of Life Flashcards

Biology: The study of living organisms and their interactions with the environment.
Definition of Life: Requires the ability to replicate independently without relying on another host organism (e.g., bacteria are living organisms, whereas viruses like COVID are technically non-living).
Biological Organization: Organisms consist of highly organized structures, progressing from cells to tissues, organs, and complex organ systems.
Response to Stimuli: Organisms respond to environmental stimuli, such as Mimosa pudica folding its leaves in response to tactile touching.

Origin: Sir Francis Bacon (1561–1626) is credited with first defining the formal scientific method.
Sequence of Steps:
- Make an observation.
- Formulate a testable question.
- Construct a hypothesis to answer the question.
- Make a prediction based on the hypothesis.
- Conduct an experiment to test the prediction.
- Analyze results using statistical analysis to accept or refute the hypothesis.

Scientific Method Flowchart

Independent Variable ( $x$ ): The specific factor manipulated by the researcher to assess its impact (e.g., type or amount of fertilizer, drug dosage).
Dependent Variable ( $y$ ): The measured outcome that responds to changes in the independent variable (e.g., plant growth/biomass, health improvement).

Independent vs Dependent Variables

Null Hypothesis ( $H_0$ ): Accepted when experimental data does not support the hypothesis, asserting that no relationship exists between factor $x$ and factor $y$ .
Controls: Standardized experimental conditions kept identical across test groups (e.g., age, sex, diet, housing, saline sham injections) to isolate the variable being tested.

Deductive Reasoning: Moves from a general premise to predict specific results (e.g., "Harold is a man, all men are mortal, thus Harold is mortal"). Forms the logical basis for hypothesis testing.
Inductive Reasoning: Takes specific observations to draw broad general conclusions (e.g., "My dog barks, his dog barks, so all dogs bark"). Highly susceptible to false predictions.