The Science of Life Chapter 1 Table of Contents Section 1 The World of Biology Section 2 Themes in...

The Science of LifeChapter 1

Table of Contents

Section 1 The World of Biology

Section 2 Themes in Biology

Section 3 The Study of Biology

Section 4 Tools and Techniques

Section 1 The World of BiologyChapter 1

Objectives

• Relate the relevance of biology to a person’s daily life.

• Describe the importance of biology in human society.

• List the characteristics of living things.

• Summarize the hierarchy of organization within complex multicellular organisms.

• Distinguish between homeostasis and metabolism and between growth, development, and reproduction.

Section 1 The World of BiologyChapter 1

Biology and You

• Biology and Society– Biology is the study of life and can be used to

both solve societal problems and explain aspects of our daily lives.

Section 1 The World of BiologyChapter 1

Characteristics of Life

• Living things share the same 7 characteristics o properties: organization and cells, response to stimuli, homeostasis, metabolism, growth and development, reproduction, and evolution.

Chapter 1

The Seven Properties of Life

Section 1 The World of Biology

Section 1 The World of BiologyChapter 1

Characteristics of Life, continued• Organization and Cells

– 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.

– Unicellular- organisms are made up one cell.– Multicellular organisms are made up of many

cells and show a hierarchy of organization going from the organism to the atom.

Section 1 The World of BiologyChapter 1

Characteristics of Life, continued

• Organization and Cells

Section 1 The World of BiologyChapter 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 BiologyChapter 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.

Section 1 The World of BiologyChapter 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.

Section 1 The World of BiologyChapter 1

Characteristics of Life, continued

• Growth and Development– The growth of living things results from the

division and enlargement of cells.

Section 1 The World of BiologyChapter 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. – Continuous: offspring similar to parent– Metamorphic: major body changes occur

Section 1 The World of BiologyChapter 1

Characteristics of Life, continued

• Reproduction– Living organisms pass on hereditary information

from parents to offspring, also called reproduction.

Section 1 The World of BiologyChapter 1

Characteristics of Life, continued

• Reproduction– Living organisms pass on hereditary information

from parents to offspring, also called reproduction.

– Asexual: one parent, creates two identical offspring.

– Sexual: two parent combine genetics to create unique offspring that are genetically different from the parent.

Section 1 The World of BiologyChapter 1

Characteristics of Life, continued

• Change Through Time– Populations of living organisms evolve or change

through time. – This leads to adaptations for survival.

The Science of LifeChapter 1

Table of Contents

Section 1 The World of Biology

Section 2 Themes in Biology

Section 3 The Study of Biology

Section 4 Tools and Techniques

Section 2 Themes in BiologyChapter 1

Objectives

• Identify three important themes that help explain the living world.

• Explain how life can be diverse, yet unified.

• Describe how living organisms are interdependent.

• Summarize why evolution is an important theme in biology.

Section 2 Themes in BiologyChapter 1

Diversity and Unity of Life

• Unity in the Diversity of Life– Life is so diverse,or full of variety. Yet, life is also

characterized by unity, or features that all living things have in common.

Section 2 Themes in BiologyChapter 1

Diversity and Unity of Life, continued

• Unity in the Diversity of Life– The tree of life shows that all living things have

descended with modification from a single common ancestor. Yet, there are many different lineages, or branches, representing different species.

Chapter 1

Phylogenetic Diagram of Living Organisms

Section 2 Themes in Biology

Section 2 Themes in BiologyChapter 1

Diversity and Unity of Life, continued

• Three Domains of Life– The three domains of life are Bacteria, Archaea,

and Eukarya.– The six kingdoms include Archaea, Bacteria,

Protista, Fungi, Plantae, and Animalia.

Section 2 Themes in BiologyChapter 1

Interdependence of Organisms

• Organisms live in interdependent communities and interact with both organisms and the environment.

Section 2 Themes in BiologyChapter 1

Evolution of Life

• Evolution, or descent with modification, is the process in which the inherited characteristics within populations change over generations.

• Evolution helps to explain how species came to exist, have changed over time, and adapt to their environment.

Section 2 Themes in BiologyChapter 1

Evolution of Life, continued

• Natural Selection– Natural selection is a process by which

organisms that have certain favorable traits are better able to survive and reproduce successfully than organisms that lack these traits.

– Natural selection can lead to the evolution of populations.

The Science of LifeChapter 1

Table of Contents

Section 1 The World of Biology

Section 2 Themes in Biology

Section 3 The Study of Biology

Section 4 Tools and Techniques

Section 3 The Study of BiologyChapter 1

Objectives• Outline the main steps in the scientific method.

• Summarize how observations are used to form hypotheses.

• List the elements of a controlled experiment.

• Describe how scientists use data to draw conclusions.

• Compare a scientific hypothesis and a scientific theory.

• State how communication in science helps prevent dishonesty and bias.

Section 3 The Study of BiologyChapter 1

Science as a Process

• Steps of the Scientific Method– The scientific method involves making

observations, asking questions, forming hypotheses, making predictions, designing experiments, analyzing data, and drawing conclusions.

Section 3 The Study of BiologyChapter 1

Scientific Processes

Section 3 The Study of BiologyChapter 1

Observing and Asking Questions• The process of science begins with an observation.

• An observation is the act of perceiving a natural occurrence that causes someone to pose a question.

• A hypothesis is a proposed explanation for the way a particular aspect of the natural world functions.– Predicting

• To test a hypothesis, scientists make a prediction that logically follows from the hypothesis.

Chapter 1

Performing the ExperimentA controlled experiment compares an experimental group and a control group and only has one variable.

Controlled Experiment and Variable

Section 3 The Study of Biology

Section 3 The Study of BiologyChapter 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 BiologyChapter 1

Designing an Experiment, continued

• Performing the Experiment– The experimenter manipulates the independent

variable.– The experimenter measures the dependent

variable because it is is affected by the independent variable.

Chapter 1

• Performing the Experiment– The experimenter manipulates the

independent variable.– The experimenter measures the dependent

variable because it is affected by the independent variable.

Independent and Dependent Variables

Section 3 The Study of Biology

Section 3 The Study of BiologyChapter 1

Designing an Experiment, continued

• Testing the Experiment– Experiments should be conducted without bias

and they should be repeated. • Analyzing and Comparing Data

– Scientists analyze data to draw conclusions about the experiment performed.

Section 3 The Study of BiologyChapter 1

Drawing Conclusions

• Making Inferences– An inference is a conclusion made on the basis of

facts and previous knowledge rather than on direct observations.

• Applying Results and Building Models– Scientists often apply their findings about the

natural world to solve practical problems.

Section 3 The Study of BiologyChapter 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.

Section 3 The Study of BiologyChapter 1

Communicating Ideas

• Publishing a Paper– Scientists submit research papers to scientific

journals for publication.– In peer review, the editors of a journal will send

submitted papers out to experts in the field who anonymously read and critique the paper.

Section 3 The Study of BiologyChapter 1

Honesty and Bias

• Communication between scientists about their methods and results helps prevent dishonesty and bias in science.

• Conflict of Interest– The threat of a potential scandal based on

misleading data or conclusions is a powerful force in science that helps keep scientists honest and fair.

The Science of LifeChapter 1

Table of Contents

Section 1 The World of Biology

Section 2 Themes in Biology

Section 3 The Study of Biology

Section 4 Tools and Techniques

Section 4 Tools and TechniquesChapter 1

Objectives

• List the function of each of the major parts of a compound microscope.

• Compare two kinds of electron microscopes.

• Describe the importance of having the SI system of measurement.

• State some examples of good laboratory practice.

Section 4 Tools and TechniquesChapter 1

Microscopes as Tools

• Light Microscopes– A compound light microscope is a microscope

that shines light through a specimen and has two lenses to magnify an image.

– Four major parts of a compound light microscope are the ocular lens, objective lens, stage, and light source.

Section 4 Tools and TechniquesChapter 1

Microscopes as Tools

• Light Microscopes– The eyepiece magnifies the image.– The objective lens enlarges the specimen.– The stage is a platform that supports slides with

specimens.– The light source is a light bulb that provides light

for viewing images.

Section 4 Tools and TechniquesChapter 1

Microscopes as Tools, continued

• Magnification and Resolution– Magnification is the increase of an object’s

apparent size.– Resolution is the power to show details clearly in

an image.

Section 4 Tools and TechniquesChapter 1

Object Size and Magnifying Power of Microscopes

Section 4 Tools and TechniquesChapter 1

Microscopes as Tools, continued

• Electron Microscopes– In an electron microscope, a beam of electrons

produces an enlarged image of the specimen. – Electron microscopes provide greater

magnification and resolution than light microscopes.

Section 4 Tools and TechniquesChapter 1

Microscopes as Tools, continued

• Electron Microscopes– Scanning electron microscopes pass a beam of

electrons over the specimen’s surface for better viewing the external surface of a specimen.

Section 4 Tools and TechniquesChapter 1

Microscopes as Tools, continued

• Electron Microscopes– Transmission electron microscopes transmit a

beam of electrons through a thinly sliced specimen for better viewing the internal structures of a specimen.

Section 4 Tools and TechniquesChapter 1

Units of Measurement

• Base and Other Units– Scientists use a single, standard system of

measurement, called the metric system. The official name of the metric system is Système International d’Unités or SI.

Section 4 Tools and TechniquesChapter 1

Units of Measurement

• Base and Other Units– The metric

system has seven base units.

Section 4 Tools and TechniquesChapter 1

Safety

• Good Laboratory Practice– Lab safety involves safe and common-sense

habits such as never working alone in a lab or without proper supervision by the teacher.

The Science of LifeChapter 1

Table of Contents

Section 1 The World of Biology

Section 2 Themes in Biology

Section 3 The Study of Biology

Section 4 Tools and Techniques