Ch. 1 Biology: The Study of Life

1. Ch. 1 Biology: The Study of Life

2. 1.1 What is Biology? • Biology – study of life • Order in natural world • Living things do not exist in isolation

3. Biologists study • interactions of life • interactions of environment • study of one species always involves the study of other species with which it interacts • problems & propose solutions

4. Organism – anything that possesses all of the characteristics of life

5. Characteristics of life

6. Orderly structure • composed of 1 or more cells • cells form structures that carry out essential functions, ex. Digestion

7. Reproduce • essential for continuation of species • species – group of organisms that can interbreed & produce fertile offspring in nature

8. Growth & development • growth – results in an increase in amount of living material & formation of new structures • development – sum total of changes that take place over organism’s life

9. Adjust to environment • environment – an oranism’s surroundings including air, H2O, weather, temperature, other organisms • stimulus – any environmental cond. That requires an organism to adjust • response – reaction to stimulus • homeostasis – regulation of organism’s internal envir. to maintain cond. suitable for survival • occurs in all living things • living things also respond to internal changes

10. Adapt & evolve • adaptation – any structure, behavior, or internal process that enables an org. to respond to stimuli & better survive in an envir. • inherited from previous generations • evolution – gradual accumulation of adaptations over time

11. All characteristics of life require energy (E) • E – ability to do work • organisms get E from food

12. 1.2 Methods of Biology

13. Scientific methods – the common steps that scientists use to gather info & answer ? • observe • hypothesize • hypothesis – explanation for a ? or problem that can be formally tested

14. Experiment • procedure that tests a hypothesis by collecting info under controlled cond. • controlled experiment – involves 2 groups – only 1 cond. is changed at a time • control – group in which all cond. are kept the same • experimental group – test group, in which all cond. are kept the same except for the one being tested • independent variable – cond. that is being changed – only cond. that will affect outcome • dependent variable – cond. being tested for – results from a change in indep. var. • use tools • maintain safety

15. Working with data • gather data • analyze data • report results • verify results • form a theory • theory – a hypothesis that is supported by many separate observations & experiments, usually over a long period of time

16. Writing a lab report

17. 1.3 Nature of Biology

18. Kinds of Research • quantitative research – result in counts or measurements (numerical data) • qualitative research – descriptive, observational data

19. International System of Measurement (SI) • Advantages • Only a few basic units • Decimal system

20. Most common units are: • Meter (m) – length • Gram (g) – mass • Liter (l) – volume • Second (s) – time • Degrees Celsius (C) – temperature (temp.)

21. Science & Society • ethics – moral principles & values held by humans • pure science – scientific study that is carried out for the sake of knowledge • technology – application of scientific research to society’s needs & problems