1.1 introduction to biology p. 4-10. main idea all living things share the characteristics of life

1.1 Introduction to Biology

p. 4-10

Main Idea

All living things share the characteristics of life.

What is Biology? Biology…..

– is the science of life– examines how living things interact, how

systems function, and how they function at a molecular level.

Biology studies…..– the origins and history of life and once-

living things,– the structures of living things,– how living things interact with one another,– and how living things function.

What do Biologists do? 1. Study the diversity of life

– Ex. Jane Goodall studying chimpanzees. 2. Research disease

– Ex. Developing vaccines for small pox, chicken pox, AIDS, and other viral infections.

3. Develop technologies– Ex. Bionic hand, artificial heart

4. Improve agriculture– Ex. Develop drought resistant/insect resistant

plants 5. Preserve the environment

– Ex. Save endangered species and habitats

What are the 8 Characteristics of Living Organisms?

1. Made of one or more cells 2. Displays organization 3. Grows and develops 4. Reproduces 5. Responds to stimuli 6. Requires energy 7. Maintains homeostasis 8. Adaptations evolve over time

What is an Organism?

An organism is anything that has or once had all of these 8 characteristics.

Made of One or More Cells

All organisms are made of one or more cells.– Unicellular … bacteria– Multicellular… animals

Displays OrganizationWhat is organization?

Organization means that living things are arranged in an orderly way.

Example:– Animals are made up of cells. – Those cells different types of cells are

organized into tissues. – Different types of tissues work together to

form organs. – Different organs work together to make up

organ systems. – Organ systems work together to make up

the entire organism.

Grows and DevelopsWhat is growth and development?

Growth results in the addition of mass to an organism, and in many organisms, the formation of new cells and new structures.– An oak tree will grow – get larger -

throughout its lifetime. Development is the process of natural

changes that take place during the life of an organism.– An acorn develops into an oak tree.

ReproducesWhat is reproduction?

Reproduction is the production of offspring.– Organisms reproduce and pass along traits

from one generation to the next. – For a species to continue to exist,

reproduction must occur.

What is a species?

A species is a group of organisms that can breed with one another and produce fertile offspring.

Responds to StimuliWhat is a stimulus?

A stimulus is any change in an organism’s internal or external environment that causes the organism to react.– Internal environment- anything inside the

organism– External environment- all things that

surround the organism [air, temperature, soil, light, other organisms]

What is a response?

A response is the reaction to a stimulus.– Stimulus happens….. Then the response.– The light shines through a window on a

plant. The plant grows toward the light.– A wolf chases a deer. The deer runs away.

Being able to respond to the environment is critical for an organism’s safety and survival.

Quick Check:

What is the stimulus and what is the response?– When a toxin is poured in a certain part of

a lake, the fish in that area move away.

– When a plant is plant doesn’t receive enough water, its leaves begin to wilt.

Requires Energy

Living things need sources of energy to fuel their life functions.– Plants make their own food.– Most organisms get their energy by

consuming other organisms.

Maintains HomeostasisWhat is homeostasis?

Homeostasis is the regulation of an organism’s internal conditions– Example: When you get hot, you begin to

sweat. That sweat helps to cool down your body, maintaining homeostasis of body temperature.

Adaptations Evolve Over TimeWhat is an adaptation?

An adaptation is any inherited characteristic that results from changes to a species over time.– The venus fly trap have adapted to

nutrient/nitrogen poor soil by trapping insects and absorbing dissolved nitrogen and nutrients.

End of 1.1

1.2 The Nature of Science

p. 11 - 15

Main Idea

Science is a process based on inquiry that seeks to develop explanations.

What is science?

Science is a body of knowledge based on the study of nature.

What are characteristics of “good science”? 1. It relies on evidence. 2. It expands scientific knowledge. 3. It challenges accepted theories. 4. It questions results. 5. It tests claims. 6. It undergoes peer review. 7. It uses the metric system.

1. Relies on Evidence

Scientific explanations combine what is already known with consistent evidence gathered from many observations and experiments.

When enough evidence from many related investigations supports an idea, scientists consider that idea a theory.

What is a Theory?

A theory is an explanation of a natural phenomenon supported by many observations and experiments.– Cell theory– Theory of heredity

What is Pseudoscience?

Pseudosciences are those areas of study that try to imitate science, often driven by cultural or commercial goals.

• physiognomy- judging someone’s character or personality based on physical features

– Phrenology: reading the bumps on someone’s head

• astrology and horoscopes• reading palms

2. Expands Scientific Knowledge

The search for new knowledge is the driving force that moves science forward.

Nearly every new find causes scientists to ask more questions that require additional research.

3. Challenges Accepted Theories

Scientists welcome debate about one another’s ideas. Often disagreements occur. Then additional investigations and/or experiments are done to find what works.– For example, many ideas about how HIV is

transmitted and treated have changed due to new information.

4. Questions Results

Observations and data different from current understanding are of interest to scientists.– For example, early biologists grouped bats

and birds together because both have wings. Further study showed that bat wings were more like mammalian forelimbs.

5. Tests Claims

Whenever biologists do research, they use standard experimental procedures called controlled experiments.

6. Undergoes Peer Review

Peer review is a process by which the procedures used for an experiment and the results are tested by other scientists in that area of study.

7. Uses Metric System

The metric system uses units with divisions that are powers of 10.

What is SI?

The International System of Units

– Examples:

• meter – used to measure length

• Gram – used to measure mass

• Liter – used to measure volume

• Second – used to measure time

Science in Everyday Life

In order to understand the huge amount of information about science available in print, on line, and on TV, and to participate in the fast-paced world, each of us must be scientifically literate.

Many issues faced every day relate to the world of biology.– Drugs, alcohol, tobacco, AIDS, mental

illness, cancer, heart disease

Science in Everyday Life

There are many issues you and future generations will face. Many involve ethics, which is a set of moral principles or values.– Euthanasia- permitting death for reasons of

mercy– Cloning- producing genetically identical

individuals– Cryonics- freezing a dead person or animal

with the hope of reviving it in the future

1.3 Methods of Science

p. 16 - 21

Main Idea

Biologists use specific methods when conducting research.

What are the Methods of Science? 1. Ask a question 2. Form a hypothesis 3. Collect Data 4. Analyze the Data 5. Report Conclusions

Ask a Question

Scientific inquiry (scientific asking questions) begins with observation.

Observation is a direct method of gathering information in an orderly way.

Observation is combined with– collecting information,– prior knowledge, and– related research.

Make inferences.

What is an inference?

An inference is combining what you have observed with what you already know and making logical conclusions.

Example:– I have seen it rain when the sky becomes

very dark and cloudy. I know that rain comes from clouds. I can infer that when the sky becomes dark and cloudy, it will rain.

What is the scientific method?

The scientific method is attempting to answer a question by: – 1. making observations– 2. ask a question– 3. forming a hypothesis– 4. experimenting– 5. collecting and analyzing data– 6. and drawing conclusions

Form a Hypothesis

A hypothesis is a testable explanation of a situation.

What is an experiment?

An experiment is an investigation done in a controlled setting to test a hypothesis.

Controlled Experiment

A controlled experiment has two groups– a control group and an experimental group.– Control group: the group in an experiment

used for comparison– Experimental group: the group in an

experiment exposed to the factor being tested

Quick Check:

In my experiment, I am testing the effects of plant food on plant growth. I have 3 plants. Plant A will receive the recommended amount of plant food. Plant B will receive twice the amount of plant food. Plant C will not receive any plant food.

– What is the control group and what is the experimental group?

Experimental Design

When scientists design a controlled experiment, only one factor can change at a time—the independent variable.– Independent variable: the tested factor

Scientists measure a second factor—the dependent variable.– Dependent variable: results from or

depends on changes to the independent variable

Quick Check:

In our plant experiment…..

– What is the independent variable?

– What is the dependent variable? What do we want to see?

Experimental Design

A constant is a factor that remains fixed during an experiment while the independent and dependent variables change.

– In our plant experiment, some constants may be amount of sunlight, type of soil, type of plants

Data Gathering

As scientists test their hypotheses, they gather data– information gained from observations.– Quantitative: numbers – measurements of

time, distance, mass, volume– Qualitative: descriptions of what our

senses detect

Analyze the Data

As biologists look for explanations, patterns are usually found to help explain the data.

The data is organized in tables and graphs.

The graphs make patterns easier to see and understand.

Analyze the Data

Analysis of the data might lead to…..– a conclusion the the hypothesis has been

supported.– additional hypotheses.– further experimentation.

Even when a hypothesis has not been supported, it is valuable.

Report Conclusions

Biologists report their findings and conclusions in scientific journals.

Before the work can be published, it goes through a peer review.– Checked for mistakes, accuracy,

conclusions

What do you think the mass of the anole will be at 21 days?

End of Ch. 1