Chapter 1: The Science of Life

The Science of Life Chapter 1 Table of Contents Section 1 The World of BiologySection 1 The World of Biology –What is biology? What are the properties of life? Section 2 Themes in Biology (Skim)Section 2 Themes in Biology –How is life diverse? What is interdependence? What is evolution? Section 3 The Study of BiologySection 3 The Study of Biology –How are problems solved in biology? Section 4 Tools and Techniques (will do in Ch 4)Section 4 Tools and Techniques –What do you know about the microscope?

Section 1 The World of Biology Chapter 1 Biology What is Biology? the study of life The study of living things Questions that biologists (scientists that study biology) have: How do living things work? How do living things interact? How do living things change over time? How diverse are living things?

Section 1 The World of Biology Chapter 1 Characteristics of Life Living things share the same 7 characteristics 1.Cellular organization 2.Reproduction & Heredity 3.Metabolism 4.Homeostasis 5.Response to stimuli 6.Growth and development 7.Evolve

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Cellular Organization –Organization is the high degree of order within an organism’s internal and external parts and in its interactions with the living world. –A cell is the smallest unit of an organism that can perform all life’s processes.

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Organization and Cells –Multicellular organisms are made up of many cells and show a hierarchy of organization going from the smallest unit of matter, the atom, to the actual organism Atom, molecule, macromolecule, organelle, cell, tissue, organ, organ system, organism

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Reproduction –Living organisms produce new organisms like themselves –Is essential for the continuation of the species –Two types: Asexual and Sexual

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Heredity During reproduction, organisms transmit hereditary information to their offspring Hereditary information is contained in genes on strands of DNA

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Metabolism –Metabolism is the sum of all the chemical reactions that take in and transform energy and materials from the environment. –Includes photosynthesis, cellular respiration, digestion etc.

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Homeostasis –All living things have mechanisms that allow them to maintain stable internal conditions. Homeostasis is the maintenance of a stable level of internal conditions even though environmental conditions are constantly changing. –How do we maintain 98.6 degrees when we are cold? –How do we maintain 98.6 degrees when we are hot?

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Response to Stimuli –Another characteristic of life is that an organism can respond to a stimulus—a physical or chemical change in the internal or external environment.

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Growth and Development –The growth of living things results from the division and enlargement of cells. –Development is the process by which an organism becomes a mature adult.

Section 1 The World of Biology Chapter 1 Characteristics of Life, continued Change Through Time –Populations of living organisms evolve or change through time.

Section 3 The Study of Biology Chapter 1 Science as a Process Steps of the Scientific Method –The scientific method is a way scientists solve problems and run controlled experiments –There are 7 steps

7 Steps of the scientific method 1.Observation/ Question/ Problem 2.Research 3.Hypothesis 4.Predictions – predict based on a true hypothesis 5.Controlled experiment – only one variable is manipulated 6.Analysis of data 7.Conclusion

Section 3 The Study of Biology Chapter 1 Designing an Experiment, continued Performing the Experiment –The control group provides a normal standard against which the biologist can compare results of the experimental group. –The experimental group is identical to the control group except for one factor.

Section 3 The Study of Biology Chapter 1 Designing an Experiment, continued Performing the Experiment –The experimenter manipulates the independent variable. (manipulative variable) –The experimenter measures the dependent variable because it is is affected by the independent variable. (responding variable)

Section 3 The Study of Biology Chapter 1 Drawing Conclusions Making Inferences –An inference is a conclusion made on the basis of facts and previous knowledge rather than on direct observations.

Section 3 The Study of Biology Chapter 1 Constructing a Theory A theory is a set of related hypotheses confirmed to be true many times, and it can explain a great amount of data. Examples of theories: Cell theory Theory of evolution With advanced knowledge and scientific tools, it may be possible to disprove a theory Example: spontaneous generation theory

Francisco Redi Didn’t believe the spontaneous generation theory that living things can spontaneously come to life from nonliving things – maggots from meat