1. Chapter 2: The Science of Biology

2. 1.Investigate and understand the natural world 2.Explain events in the natural world 3.Use those explanations to make useful predictions.

3. State the Problem Form a Hypothesis Set Up a Controlled Experiment Record Results Analyze Results Draw a Conclusion Publish Results

4. independent variableA hypothesis should be tested by an experiment in which only one variable, the independent variable, is changed at a time. dependent variableThe result that you measure is called the dependent variable controls or controlled variablesAll other variables, the controls or controlled variables, should be kept unchanged, or controlled.

5. Controlled Variables: jars, type of meat, location, temperature, time Manipulated Variables: gauze covering that keeps flies away from meat Section 1-2 In 1668, Francisco Redi proposes an experiment to prove that maggots do not arise from meat “out of nowhere.” Identify the following components of Redi’s experiment: Dependent variable Independent variable Controlled variables According to the diagram, what should Redi conclude?

6. A hypothesis is a prediction, or educated guess about why or how something occurs in nature. A theory is when a particular hypothesis is supported by many scientists after rigorous testing.

7. Biology: The study of life or living and once- living things. Living things share 8 characteristics. No single characteristic sufficiently describes a living thing.

8. CharacteristicDescription Made of cells Many microorganisms such as bacteria are unicellular; Plants and animals are multicellular Reproduce Maple trees reproduce sexually; Hydra reproduce asexually through budding Based on a universal genetic code (DNA) Flies produce flies, dogs produce dogs, seeds from maple trees produce maple trees Obtain and use materials and energy Plants obtain their energy from the sun; Animals obtain their energy from the food they eat Grow and develop Flies begin life as eggs, then become maggots, then become adult flies. Respond to their environment Leaves and stems of plants grow towards light Maintain homeostasis Despite changes in the temperature of the environment, a robin maintains a constant body temperature. As a group, change over time (evolution) Plants that live in the desert survive because they have become adapted to the conditions of the desert.

9. What are cells? Cells – collection of living matter enclosed by a barrier that separates the cell from its surroundings. Organisms consisting of only one cell are unicellular (bacteria) Organisms consisting of more than one cell are multicellular (dogs, trees, humans)

10. 2 Types of Reproduction Sexual reproduction: requires two cells from different individuals unite to produce the first cell of a NEW organism. Asexual reproduction : a single organism can reproduce without the aid of another.

11. Growth and Development Most living things go through a cycle of change called development. A single cell that starts an organism’s life divides and changes again and again to form the many and varied cells of an adult organism. As this process continues, organisms experience a process called aging in which the organism becomes progressively less efficient and eventually dies.

12. Obtaining and Using Energy All organisms require energy to build the substances that make up their cells. Metabolism: the total sum of all chemical reactions in the body. Anabolism: process in a living thing that involves putting together or synthesizing, complex substances from simpler ones (Example?) Catabolism: process in a living thing that involves the breakdown of complex substances into simpler ones (Example?) Anabolism Catabolism

13. Responding to Their Environment Stimulus - anything in the environment that causes an organism to react. (Examples?) Irritability – the ability of living things to respond to stimuli. (Plant leaves, stems & roots) Homeostasis – an organism’s ability to maintain constant or stable conditions that are necessary for life... Examples?