Do Now1. Get a packet from the desk in the

back of the room and write your name on it.

2. In your notebooks write the date in the margin and the following Do Now assignment

• What is it that you think makes something alive?

Chapter 1

Biology: The Study of Life

Section 1.1 What is Biology?

The Science of Biology• People have always been curious

about living things

• The concepts, principles, and theories that allow people to understand the natural environment form the core of Biology

Biology• The study of Life

Bio logy (greek)

Life Study of

Biologists study the interactions of life.

Biologists study the diversity of life.

• Throughout your study of biology you will come to appreciate the great diversity of life on Earth

Biologists study the interactions of the environment.

• No living thing exists in isolation

• The study of biology includes the investigation of living interactions

• The study of one living thing always involves the study of the others in which it interacts

Ex.) studying wild rats means you have to study what it eats and what eats it

Biologists study problems and propose solutions.

• Medical treatment

• Disease prevention (humans and other organisms)

• Endangered species prevention

Where are all the bees?

Characteristics of Living Things

• Biologists have formulated a list of characteristics by which we can recognize living things

Organisms

• Anything that possess all the characteristics of life

1. Living things are organized

organization• Orderly structure

• All organisms are composed of one or more cells which contain the genetic material or DNA that provides all the information needed to control the organisms life processes

2. Living things make more living things

Reproduction• The production of offspring

• Reproduction is not essential for the survival of an organism, but it is essential for the continuation of the organisms species

Species• A group of organisms that can

interbreed and produce fertile offspring in nature

3. Living things change during their lives

Growth• An increase in the amount of

living material and the formation of new structures

Development• All the changes that take place

during the life of an organism

4. Living things adjust to their surroundings

Environment• An organisms surroundings

Ex.) air, water, weather, temperature, other organisms in the area

Stimulus• Anything in an organisms external

or internal environment that causes the organism to react

Response• A reaction to a stimulus

Homeostasis• Regulation of an organisms

internal environment to maintain conditions suitable for survival

Ex.) Body temp regulation, water, minerals

• Without this ability to adjust to internal changes, organisms die

Energy• The ability to cause change

• Organisms get their energy from food

5. Living things adapt and evolve

Adaptation• any structure, behavior, or

internal process that enables an organism to respond to environmental factors and live to produce offspring

• Anything that makes an organism better at life

How Adaptations Work• Adaptations are inherited from

previous generations• There are always some

differences in the adaptations of individuals of a population

• As the environment changes, some adaptations are more suited to the new conditions than others

• Individuals with more suitable adaptations are more likely to survive and reproduce

• As a result, individuals with these adaptations become more numerous

Evolution

Evolution• The gradual change in a species

through adaptations over time

• Clues to the way present diversity of life came about may be understood through the study of evolution

In Conclusion• As we learn more about Earth’s

organisms in this course, take time to reflect on the general characteristics of life

• Rather than simply memorizing facts about organisms or the vocabulary terms, try to see how these facts and terms are related to the characteristics of living things

Do Now

• Finish answering questions on page 4. I would like to go over the answers in about 3 minutes.

Section 1.2 The Methods of Biology

Why does rain bring out the worms?

Observing and Hypothesizing

• Curiosity is often what motivates biologists to try to answer simple questions about everyday observations

• The knowledge obtained when scientists answer questions provides better understanding of general principles or may lead to practical applications or may lead to new questions

The Methods Biologists Use

Scientific Methods• The common steps that scientists

use to gather information and answer questions

• Scientific methods usually begin with identifying a problem to solve

The Story of the Brown Tree Snake

Hypothesis• An explanation for a question or a

problem that can be formally tested

• A hypothesis is not a random guess!

• The scientist has some idea of what the answer might be through personal observations, extensive research, or previous investigations

Experiment• An investigation that tests a

hypothesis by the process of collecting information under controlled conditions

What is a controlled experiment?

• Some experiments involve two groups: the control group and the experimental group

Control• The group in which all conditions

are kept the same

Experimental Group• The test group in which all

conditions are kept the same except for the single condition being tested

Does fertilizer help plants grow taller?

Water + Fertilizer Water

Designing an experiment

• In a controlled experiment, only one condition is changed at a time

Does fertilizer help plants grow taller?

Water + Fertilizer Water

Controls

•Same volume of water

•Same temperature

•Same sun exposure

Independent variable• The condition in an experiment

being changed

Dependent variable• The condition that results from a

change in the independent variable

Gro

wth

(cen

timet

ers)

Fertilizer No Fertilizer

Does fertilizer help plants grow taller?

Now You Try…

A number of rats are divided into two groups: One group is fed a normal diet, whereas the other group is fed the same diet but with one necessary mineral left out. The animals receiving the normal diet remained healthy; those in the other group grew weaker. Formulate a hypothesis based on this experiment.

A scientist conducted an experiment to determine the effect of environment on the color of fur of a Himalayan rabbit. The Himalayan rabbit typically has a white coat except for its colder nose, feet, tail, and ears, which are black. The scientist shaved an area of hair on the back of each rabbit, then placed an ice pack over the shaved area on one rabbit (A).

Using Tools• To carry out investigations,

scientists need tools that enable them to record information

Maintaining Safety• Safety is another important factor

that scientists consider when carrying out investigations

Safety Symbol• A symbol that warns you about a

danger that may exist from chemicals, electricity, heat, or procedures you will use

Safety Symbols

Gathering Data• To answer their questions about

scientific problems, scientists seek information from other investigations

Data• Info obtained from investigations

or experimental results

Thinking about what happened• After careful review of the results, the scientist

must come up with a conclusion• Was the hypothesis supported by the data?• Was it not supported? Is more data needed?• Does the experiment need to be repeated?• After analyzing the data, most scientists have

more questions than they had before the investigation

Reporting results• Results and

conclusions of investigations are reported in scientific journals

Verifying results• When a hypothesis that is

supported by many separate observations and investigations usually over a long period of time, becomes a theory

Theory• An explanation of a natural phenomenon

that is supported by a large body of scientific evidence obtained from many different investigations

• A theory results from continual verification and refinement of a hypothesis

• In addition to theories, scientists also recognize certain facts of nature called laws or principles

Ex.) gravity

Do Now• Get your homework out (pg 8)

and place it on top of your desk so I can check it.

• In your notebook, please describe this class in anyway you’d like.

Do Now

200 carrot seeds each were used in an investigation to test for the influence of temperature on germination of seeds. Group A had 150 seeds and was kept at a temperature of 20 degrees Celcius and Group B had 50 seeds and was kept at 10 degrees Celcius. All other conditions were the same.

Section 1.3 The Nature of Biology

Kinds of Information• Scientific information can usually

be classified into one or two main types, qualitative or quantitative

Quantitative information• Numerical data

• Numerical values are compared

• Quantitative data may be used to make graphs or tables

Measurements in the International System

• Scientists use a form of the metric system called the International System of measurements or SI

Q: Why is it important that all scientific measurements be done in the same way?

A: Not everyone uses the English system of measurements that we use

Advantage of SI• Only a few basic units

• Decimal system, measurements can be expressed in multiples of ten or tenths of a basic unit by applying a standard set of prefixes to the unit

• In biology, the metric units you will encounter most often are…

Metric Units• _______________ (length)

• _______________ (mass)

• _______________ (volume)

• _______________ (time)

• _______________ (temperature)

meter

gram

litersecond

Celsius

Qualitative information• Observational data

• Some phenomena aren’t easily expressed as quantitative information

Science and Society• Some people blame scientists for the

existence of controversial things in science

• To comprehend the nature of science, people must understand that knowledge gained through scientific research is never inherently good or bad

• Society as a whole must take responsibility for the ethical use of scientific discoveries

Ethics• The moral principles and values

held by humans

Can science answer all questions?

• No, some questions are simply not in the realm of science

• Ex.) good vs. evil, ugly vs. beautiful

• These questions cannot be tested using scientific methods

• However, this does not mean that these questions are unimportant

Technology

• The application of scientific research to societies needs and problems

Technology has helped us in many ways

• Increase production of food

• Decrease the amount of manual labor

• Aided in the reduction of wastes and environmental pollution

The advances of technology has resulted in some serious problems too

• Too much fertilizer can contaminate water

• Automobiles have led to increased air pollution

In Conclusion• Science and technology will never answer

all of the questions we ask, nor will they solve all of our problems

• However, during your study of Biology you will have many of your questions answered, and you will explore new concepts

• Don’t forget, you are part of this living world and you can use the process of science to ask and answer questions about that world