section 1 the world of biology chapter 1 biology and you biology and society –biology is the study...

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.

Chapter 1

The Seven Properties of Life

Section 1 The World of Biology


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.



• Organization and Cells– Multicellular organisms are made up of many

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



• 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.



• 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.



• Metabolism– Metabolism is the sum of all the chemical

reactions that take in and transform energy and materials from the environment.



• 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.



• Reproduction– Living organisms pass on hereditary information

from parents to offspring, also called reproduction.



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

through time.

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.


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


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.


Interdependence of Organisms

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


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.


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.

Chapter 1

Click below to watch the Visual Concept.

Visual Concept

Natural Selection

Section 2 Themes in Biology

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.


Scientific Processes

Chapter 1


Visual Concept

Scientific Method

Section 3 The Study of Biology


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.


Forming a Hypothesis

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


Forming a Hypothesis, continued

• Predicting– To test a hypothesis, scientists make a prediction

that logically follows from the hypothesis.


Designing an Experiment

• Performing the Experiment– A controlled experiment compares an

experimental group and a control group and only has one variable.

Chapter 1


Visual Concept

Controlled Experiment and Variable



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.



• 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


Visual Concept

Independent and Dependent Variables




• Testing the Experiment– Experiments should be conducted without bias

and they should be repeated.


Collecting and Analyzing Data

• Analyzing and Comparing Data– Scientists analyze data to draw conclusions about

the experiment performed.


Drawing Conclusions

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

facts and previous knowledge rather than on direct observations.


Drawing Conclusions, continued

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

natural world to solve practical problems.


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.


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 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.


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.


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.


Object Size and Magnifying Power of Microscopes



• 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.



• Electron Microscopes– Scanning electron microscopes pass a beam of

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

– Transmission electron microscopes transmit a beam of electrons through a thinly sliced specimen for better viewing the internal structures of a specimen.


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.


Units of Measurement

• Base and Other Units– The metric system has seven base units.


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.

section 1 the world of biology chapter 1 biology and you biology and society –biology is the study...

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