Chapter 1 – The Science of Biology!

Section 1-1: What in the world is

Science?!?!?!

What words do we associate with science?

The goal of science is to investigate and understand the ______________, to explain events, and to use those explanations to make ___________________

To simplify, science is

natural world

useful predictions

an organized way of using evidence to learn about the natural world

Science can also just refer to theknowledge scientists have complied

Scientific thinking usually starts with ________________an observation

An observation is just gathering info in an orderly way

_______= the information gathered through observations

There are 2 main types of data:

Data

qualitative and quantitative

Qualitative =____________________—written descriptions of what scientists observe.

Quantitative = results from experiments that use __________________________— numerical data can be used to make graphs, tables, or charts.counts or measurements

observational data

Qualitative Quantitative

____________ = a logical interpretation based on prior knowledge or experienceInference

So we have made our observation, now what?

Scientists come up with a ______________ – a proposed explanation for a set of observations

Hypothesis’ must be able to be tested – some through ________________________ and some through further collection of data

hypothesis

controlled experiments

new medical treatments, new sources of fuel, different uses for waste

Biology can be considered a way of knowing – it is an ongoing process because things continue to change (we don’t leave things alone!!!)

Biological research can lead to all sorts of different things;

Section 1-2: How Scientists

Work

Observations lead to questions – we need a way to test those questions. That’s where an experiment comes in.

The basic steps in designing an experiment:

1. Ask the question

5. Draw a conclusion

2. Form a hypothesis from the question3. Set up a controlled experiment

4. Record and analyze results

Aristotle had the idea that living things could come from nonliving things –there were special “vital” forces that brought this about – this became known as

To help understand each step, let’s look at some well-known experiments from history

This idea persisted for a while – it was only challenged some 400 years agospontaneous generation

These ideas were questioned because of simple observations: maggots on meat, mice on grain, beetles in poo

Redi, an Italian physician, came up with a different hypothesis as to why maggots appear on meat __________ they laid eggs

(step 1)

(step 2)

Controlled experiment = an experiment in which only _______________ is changed at a time all others are kept unchanged

Redi came up with a controlled experiment(step 3)

one variable

(controlled)

The independent variable (IV) is what you are changing/controlling/know

The dependent variable (DV) is what you are observing/counting/watching

What is the IV?What is the DV?

What is the IV?What is the DV?

We like pictures, but hate numbers, so why do we hate graphs? Its just a picture of our numbers!

What is the IV?What is the DV?

Dependent

Reactive

Y-axis

Manipulated

Independent

X-axis

Line Graph: shows change over time

Bar Graph: compares similar but separate categories

Circle/pie Graph: part of a whole thing (%)

Types of Graphs

In Redi’s experiment, he predicted that keeping flies away from meat would prevent maggots, so the variable he changed (IV) was the flies access to the meat

Redi thought that if flies couldn't get to the meat there would be no maggots, so he set up meat in 2 sets of jars – most factors were the same: the jar, type of meat, location, temp, time – the only thing that changed was

the gauze over the jar

Redi recorded his data in notebooks for future generations of scientists

Redi’s finding ___________ his hypothesis – if the flies couldn’t get to the meat, there were no maggots

(step 4)

(step 5)

supported

Experiments are often repeated to make sure that results are

A key assumption in science is that experimental results can bereproduced

valid

Sometimes it’s not always possible to do an experiment to test a hypothesis

_______________ are used as a way to make observations and gather further information to help support a hypothesis

Field studies

When there is enough evidence from several investigations and a hypothesis is very well supported it is considered

Some people might try to criticize something because it is “just a theory”, but in science, a theory is

a theory

a well tested explanation that unifies a broad range of observations

Section 1-3: Studying Life!

We ask questions all the time; how, what, when, where, why?This is exactly what biologists do – they ask questions about living things

Biology is just the study of life

Bio =Logy =

lifethe study of

So how do we classify living things; what characteristics do they have?

All living things (___________) share the following characteristics, they are:

organisms

_______ = a collection of living matter enclosed by a _____________ that separates the cell from its surroundings

1. Are made up of units called cells

Cellbarrier

_____________________ = cells from 2 parents unite to produce the first cell of the new organism

______________________= the new organism has a single parent it divides in half to form 2 new organisms

2. Reproduce

Sexual reproduction

Asexual reproduction

Organisms inherit traits from their parents through

This code determines the inherited traits of every organism on Earth

3. Based on a universal genetic code

DNA – the genetic code

For some single-celled organisms, _________ is just an increase in size

All of the changes that take place during the life of an organism =

4. Grow and develop

growth

development

Organisms need material and energy just to stay alive!

_____________= the combo of chemical reactions through which an organism builds up or breaks down materials during life processes

5. Obtain and use materials and energy

Metabolism

_________= a signal to which an organism responds

Organisms can react to both _____________________ stimuli

6. Respond to their environment

Stimulus

internal and external

_______________ = the process by which organisms keep internal conditions constant for survival

Organisms go to great lengths to maintain conditions (temp and water content)

7. Maintain a stable internal environment

Homeostasis

It can take ________________ of years for these changes to really be apparent

Ex. Desert plants have evolved and adapted to living in very hot, dry climates

8. As a group, change over time

100s or 1000s

Since there is a very large range of living things, there are many branches of Biology

Some of the levels that biology can study are…

BiospheresMolecules

Cells

Groups of cells

Organisms

PopulationsCommunities

Ecosystems

Section 1-4: Tools and Procedures

Scientists use all sorts of tools to help make observations and _____________________

We need a _________________ _________________ so that scientists all over the world can understand it

take measurements

common systemof measurement

The ________________ is a decimal system of measurement whose units are scaled on multiples of

A revised version of the metric system is the

metric system

10

International System of Measurement (SI)

Measurement

Unit Symbol

Length meter m

Mass kilogram kg

Time second s

Temperature Kelvin K

Amount of substance

mole mol

_______________= devices that produce magnified images of structures that

are too small to see with the naked eye

Microscopes

Compound light microscopes use ______ lenses to form an image

They can magnify an object by about

____________________ produce an image by focusing visible light raysLight microscopes

two

1000 times

______________________ produce an image by focusing beams of electronsImages can get 1000 times more detailed than that of a light microscope

There are 2 main types of electron microscopes:

Electron microscopes

transmission electron (TEM) and scanning electron (SEM)

TEM SEM•Shines light through thin specimen•Specimen is NOT living•Used to view details in the specimen

•Scans surface of specimen•Specimen is NOT living•Creates a 3D image of the specimen

__________ should always be practiced as biologists work with a variety of materials, living and dead

P.1066-1076 – reference page for safety procedures P.1068 in book – reference page for safety symbols

Lab safety

Sharp Object Safety

Clothing Protection Safety

Eye Safety

Chemical Safety