Transcript Chapter 1 PowerPoint

1.1
Chapter 1: The Nature of Life
Science is a way of thinking, questioning, and gathering
evidence.
1.1
1.1 Objectives:


Identify the different elements of scientific inquiry
Create testable hypotheses

Differentiate between independent variables and dependent
variables

Explain the importance of a control group

Discriminate between negative and positive controls
1.1
Chapter 1.1 Vocabulary
Science
Positive Control
Hypothesis
Negative Control
Observation
Data
Inference
Independent Variable
Derive
Dependent Variable
Control Group
Constants
1.1
What is Science


Science is an organized way of gathering and analyzing evidence about
the natural world

Science deals only with the natural world

Scientists collect and organize information in an orderly way, looking for patterns
and connections

Scientists propose explanations based on evidence, not belief

Science is a way of knowing
The goals of science are to provide natural explanations for events in the
natural world. Science aims to use those explanations to understand
patterns in nature and to make useful predictions about natural events
Think of
Science
as a VERB
not a noun
1.1
Like all science, biology is a process of
inquiry
•
•
•
•
Scientists make careful and systematic observations.
Scientists record observations as data.
Scientists form a hypothesis as a possible answer to a question.
Scientists test their hypotheses and analyze their data.
1.1
Observing & Asking Questions

Scientific investigations begin with observations, the
act of noticing and describing events or processes in a
careful orderly way

It involves more than just looking at things

“Think something that nobody else has thought yet
while looking at something that everybody sees” Arthur
Schopenhauer
1.1
Inferring and Forming a Hypothesis

An inference is a conclusion or opinion that is formed because of known
facts or evidence

Inferences and creative imagination lead to the formation of a hypothesis

A hypothesis is a scientific explanation for a set of observations that can
be tested in ways that support or reject it
1.1
Designing Controlled Experiments

Experimental studies allow scientists to determine what causes a phenomenon

A hypothesis should be tested by an experiment in which only 1 variable is
changed, everything else should be kept constant


Constants are conditions that are kept the same.

Examples might include light, temperature, time…
There are 2 types of variables scientists focus on in experiments

Independent Variables: are manipulated.

Dependent Variables: are observed and measured
1.1
Note About Writing a Good
Hypothesis

A hypothesis is a statement, not a question. Your hypothesis is not the scientific question in your project.
The hypothesis is an educated, testable prediction about what will happen.

Make it clear. A good hypothesis is written in clear and simple language. Reading your hypothesis
should tell a teacher or judge exactly what you thought was going to happen when you started your
project.

Identify the variables. A good hypothesis defines the variables in easy-to-measure terms, like who the
participants are, what changes during the testing, and what the effect of the changes will be.

Make sure your hypothesis is "testable." To prove or disprove your hypothesis, you need to be able to do
an experiment and take measurements or make observations to see how two things (your variables)
are related. You should also be able to repeat your experiment over and over again, if necessary. To
create a "testable" hypothesis make sure you have done all of these things:

Thought about what experiments you will need to carry out to do the test.

Identified the variables in the project.

Included the independent and dependent variables in the hypothesis statement.
1.1
Designing a Controlled Experiment
 Control
Groups are groups that you compare your
experimental group to, to see if your hypothesis is
supported or rejected
 Scientists
typically use at least 2 control groups
 Positive
control: A positive control gives the desired
outcome of an experiment
 Negative
control: A negative control is designed to
NOT give the desired outcome of the experiment
1.1
Example: Designing a Controlled
Experiment

You start suffering from allergies, but
don’t know what’s causing them

Your doctor decides to do an
intradermal allergy test

Like all experiments, your doctor will
use a positive control and a negative
control
1.1
1.1 Assessment: What role do
hypotheses play in scientific inquiry?

A hypothesis provides a testable explanation for an observation

It tells someone exactly what you thought was going to happen when
you started your project

It defines the variables in easy-to-measure terms
Blooms Taxonomy: Understand
1.1
1.1 Assessment: What is the difference
between an independent variable
and a dependent variable?

An independent variable is the thing you are testing

A dependent variable shows the effect of that manipulation, it’s what
you’re measuring
Blooms Taxonomy: Understand
1.1
1.1 Assessment: What is the Independent
variable and the dependent variable in
the graph below? How do you know?

The Independent variable is Time

The dependent variable is Population size

The independent variable is always on the X axis

The dependent variable is always what you
measure, and in this case we would measure
the number of people (population)
Blooms Taxonomy: Apply & Evaluate
1.1
1.1 Assessment: What is the Independent
variable and the dependent variable in
the graph below? How do you know?

The Independent variable is Precipitation

The dependent variable is Cucumber Yield

The independent variable is always on the X axis

The dependent variable is always what you
count, and in this case we would count the
number of cucumbers
Blooms Taxonomy: Apply & Evaluate
For each pair, identify which
hypothesis is better and explain why


Hypothesis 1:
A.
When there is less oxygen in the water, rainbow trout suffer more lice.
B.
Our universe is surrounded by another, larger universe, with which we can have
absolutely no contact.
Hypothesis 2:
A.
Aphid-infected plants that are exposed to ladybugs will have fewer aphids
after a week than aphid-infected plants which are left untreated.
B.
Ladybugs are a good natural pesticide for treating aphid infected plants.
Blooms Taxonomy: Evaluate
Use the information below to answer
the question

To study the effects of a mineral deficiency, 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.

The missing mineral in the diet is needed for the health of the rats.
Blooms Taxonomy: Creating
1.1
1.1 Assessment: Use the following
experiment for the next few questions



In the experiment outlined in the
table, 5 identical tomato seedlings
are planted in 5 identical pots,
placed in the same location, and
watered on identical schedules.
Identify the following
Seedling
Soil
Soil
Appearance
Plant Height at
10 days
1
Yard dirt
Damp, light
6 inches
2
Sand
Dry, course
1 inch
Wet, dense
2 inches

Independent variable
3
Clay

Dependent variable
4
10 inches

Positive control

Negative control
Miracle
Damp,
grow
nutrient rich
potting soil

Constant
5
none
0 inches
Write a hypothesis for this
experiment
Empty pot
Blooms Taxonomy: Apply, analyze, evaluate
Friday September 5th Announcements

If you haven’t already done so please get you lab safety contracts
signed and handed in

You should read CH1.1-1.2 for homework and be studying the
vocabulary

On Monday you will need your composition Notebooks and a 3
ring binder no later than Tuesday

If you had a difficult time on the last question from yesterday,
please see me for extra tutoring before or after school or during
lunch

Journal Club: If you received an email from Ms. Kim please bring
your lunch to my room Monday for journal club
1.2
Chapter 1.2
Science
in
Context
TECHNOLOGY
CONTINUALLY CHANGES
THE WAY BIOLOGISTS
WORK.
1.2
1.2 Objectives

List attitudes important to science

Describe the usefulness of peer review in evaluating scientific literature

Differentiate between theories and hypotheses

Evaluate the importance of biology in making informed decisions

Summarize the benefits and risks of the application of biotechnology

Explain how advances of technology might affect the future of biology.
1.2
1.2 Vocabulary
Scientific Theory
Peer Review
Bias
Scientific Law
DNA
Biotechnology
Transgenic
1.2
Scientific Attitudes

Good scientists share scientific attitudes, or habits of mind,
that lead them to exploration & discovery

Skepticism: good scientists question everything and refuse to
accept explanations without evidence

Open-mindedness: Good scientists are willing to accept
different ideas, even when they disagree with their
hypothesis, as long as they are supported by evidence

Creativity: researchers need to think creatively to design
experiments
1.2
Communicating Results:
Reviewing & Sharing Ideas

Peer Review

Scientists share their finding by publishing articles that have undergone
peer review

History of Nature: Discoveries
http://www.nature.com/nature/history/video/index.html

In peer review, scientific papers are reviewed by anonymous,
independent experts who check for mistakes in the procedure
and bias
1.2
Scientific Theories

Evidence from many scientific studies may support several related hypotheses in a
way that inspires researchers to propose a scientific theory that ties those hypothesis
together

It is important to note, the word theory is used different
in science than it is in everyday
SCIENCE
life
CHANGES AS


Every day life “I have a theory” means little more than
“ I have an idea”
IT DISCOVERS
NEW that unifies a broad range of
In science, the word theory applies to a well tested explanation
EVIDENCE!
observations and hypotheses and that enables scientists
to make accurate predictions in
new situations

No theory is considered absolute truth

As new evidence is uncovered, a theory may be revised or replaced by a more useful explanation
1.2
Scientific Theories vs Laws
Theories

More dynamic & complex

Encompass a greater number of ideas
and hypotheses

Are constantly fine-tuned as new
discoveries are made

Examples:
Laws

Concise specific descriptions of how
some aspect of the natural world is
expected to behave in a certain
situation

Examples:

Law of gravity

Cell theory

Newtons laws of motion

Theory of Evolution

Ideal gas laws
1.2
Science & Society

Using science involves understanding its context in society and its
limitations

Pure science does not include ethical or moral view points

Science can tell us how certain knowledge or technology can be applied, but
not whether it should
1.2
Science & Society

Avoiding Bias

Science aims to be objective, but scientists may
make recommendations that are not in the
best public interest due to bias

A bias is a particular preference or point of view Underline or highlight me in your notes!
that is personal, rather than scientific

The public must be educated enough to
understand science to make certain it is
applied in ways that benefit humanity
1.2
Understanding & Using Science

Understanding biology helps us realize that we
can predict the consequences of our actions
and take an active role in directing our future
and that of our planet

In our society, scientists make
recommendations about big public policy
decisions, but they don’t make decisions

Citizens of our democracy make decisions by
voting for elected officials who influence
public policy. This is why it is so important we all
understand how science works and
appreciate both its power and limitations
Your health and the health of the
environment depend on your
knowledge of biology.

Knowledge of biology helps you understand your health.

food allergies

potential effects and causes of obesity


Cancer


http://www.nature.com/nature/videoarchive/gutmicrobes/
http://www.nature.com/nature/videoarchive/smokinglungcancer/
brain
Effects of alcohol, tobacco, and other drugs
lungs
heart
liver
kidneys
1.2
1.2
Knowledge of biology can help you
understand environmental issues

Interactions in ecosystems

Pollution

Biodiversity
1.2
Biotechnology offers great promise but
also raises many issues.

Biotechnology is the use and application of living things and
biological processes.

–
–
DNA testing in medicine and forensics
transgenic (genetically modified) crops
transgenic bacteria
1.2
Questions are raised about the use of
biotechnology.

safety of genetically modified crops

spread of undesirable genes

decrease in biodiversity

ethical considerations
1.2
1.2 Why is peer review so important to
science?

It allows researchers to share ideas and test and evaluate each others
work

Peer review may help reduce personal bias in the scientific
community
Blooms Taxonomy: Understand
1.2
1.2 Why do reviewers of scientific
papers have to be anonymous and
independent?

Reviewers must be anonymous and independent so that they are not
biased or influenced by the ideas in the papers or the scientists who
wrote the papers.
Blooms Taxonomy: Understand
1.2
1.2 Why is it NOT useful to view
science as a set of facts?

Science is always changing and advancing so the facts may change
over time.
Blooms Taxonomy: Understand
1.2
1.2 Assessment: How is the meaning of
theory in science different from the
typical use of the every day term

A scientific theory is a widely accepted explanation that is supported
by evidence.

In everyday language, a theory is a guess.
Blooms Taxonomy: Analyze
1.2
1.2 Assessment: how are hypotheses
and theories related?

A theory is a well-tested explanation that unifies a broad range of
observations;

A hypothesis is a proposed, testable, scientific explanation for a set of
observations.

Hypotheses and theories are both proposed explanations for a
scientific question.

Observations and data collected in testing hypotheses contribute to
a broader question that is addressed by a theory.

A Theory, in turn, provides the framework for new hypotheses.
Blooms Taxonomy: Analyze
1.2 Assessment: Give 3 examples of ways in
which biology can help you make everyday
decisions

Diet

Sunscreen

Exercise
1.2
Blooms Taxonomy: Understand
1.2
1.2 Assessment: What are some of the
potential benefits and risks of biotechnology?
Benefits



Risks
Technology in and of itself is
Treatment and prevention
not bad,ofbut howweEthical
use concerns
it
disease and illness
might be. Sometimes we
Privacy
don’t understand the
longissues
Improving crop growthterm effects of the
technologies that
we negative health and
 Potential
environmental
effects
develop
until it’s already
a
Helping to improve
quality of
environment
problem.
Blooms Taxonomy: Apply
1.2
1.2 Assessment: Scientists disagree on whether
genetically modified foods are safe to eat.

Design an experiment to test the safety of genetically modified foods. Your
experimental design must include the following

Hypothesis

Independent variable

Dependent variable

*Positive control (this one will be difficult but think about it and see what you
come up with)

Negative control
Blooms Taxonomy: Creating
1.3
Chapter 1.3
Biology: The Study of Life
CHARACTERISTICS OF LIVING THINGS & BIOLOGICAL LEVELS OF ORGANIZATION
1.3
1.3 Objectives:

Define and give examples of Earths’ biodiversity

Summarize the characteristics of all living things

List the levels of biological organization that biologists study

Identify four major unifying themes in biology

Convert between units in the metric system
1.3
CH1.3 Vocabulary
Biology
Metabolism
DNA
Biosphere
Stimulus
Biodiversity
Sexual Reproduction
Biome
Asexual Reproduction
Species
Homeostasis
Heredity
Cell
Adaptation
Evolution
Negative Feedback
Universal Genetic Code
Positive Feedback
Population
Ecosystem
Community
1.3
All organisms share certain characteristics.

Biology is the scientific study of all forms
of life.

An organism is any individual living
thing.
1.3
Characteristics of Living Things

All organisms are made of one or more
cells.

Cells are the smallest unit considered fully
alive

Cells can grow, respond to their
surroundings, and reproduce

Some living things have only 1 cell, while
others like humans have about 100 trillion
1.3
Characteristics of Living Things

Living things are based on a universal genetic
code

All organisms store the complex information they
need to live, grow, and reproduce in a genetic code
written in a molecule called DNA

That information is copied and passed from parents
to offspring through the process called heredity

The genetic code is almost identical for every single
living thing

See The Story of You at
https://www.youtube.com/watch?feature=player_embe
dded&v=TwXXgEz9o4w
1.3
Characteristics of Living Things

Living things grow and develop

Every organism has a particular pattern of growth
and development

During development, a single fertilized egg divides
again and again

As these cells divide, they differentiate, which means
they begin to look different and perform different
functions
1.3
Characteristics of Living Things

Living things respond to their environment

Organisms detect and respond to stimuli from their
environment

A stimulus is a signal to which an organism responds
1.3
Characteristics of Living Things

Living things reproduce

Most plants and animals engage in sexual
reproduction, where the cells from 2 parents (egg
and sperm) unite to form the 1st cell of a new
organism

Bacteria and some fungi and protists reproduce
through asexual reproduction, in which a single
parent produces offspring that is an exact copy of
itself
1.3
Characteristics of Living Things

Living things obtain and use material and energy

All organisms must take in materials and energy to
grow, develop, and reproduce

The combination of all the chemical reactions an
organism builds up or breaks down substances is
called metabolism
1.3
Characteristics of Living Things

Taken as a group, living things evolve

Over generations, groups of organisms evolve, or
change over time

Evolutionary change links all forms of life to a
common origin more than 3.5 billion years ago

Evidence of this shared history is found in all
aspects of living and fossil organisms, from physical
features to the structure of proteins, to the
sequences of information in DNA
1.3
Characteristics of Living Things

Living things maintain a stable internal environment

All organisms need to keep their internal environment relatively stable, even when
external conditions change dramatically.

Homeostasis is the process by which organisms maintain stable internal conditions
suitable for life
1.3
Biology Studies Life at Different Levels

Biologists study life at different levels, from as
small as the atoms and molecules necessary
for life, to as large as the entire planet
Biosphere
Level
Ecosystem
Level
Community
level
Population
level
Organisms are Classified into Species

A species is one particular type of living thing.

Members of a species can interbreed to reproduce
fertile offspring.

There are about 2 million different living species have
been identified.
Earth is home to an incredible diversity of life

The biosphere is the portion of Earth that supports life and includes all
living things and all the places they are found.

Every part of the biosphere is connected with every other part.

The biosphere includes many environments.
biosphere =
everywhere life exists
Earth is home to an incredible diversity
of life.

Biodiversity is the variety of life in a particular area

Biodiversity generally increases from the poles to the equator.

Biodiversity is greater in areas with consistently warm temperatures.
Biodiversity is
greater closer to
the equator.
1.3
1.3 Assessment: How are species
related to the concept of biodiversity

Biodiversity is the variety and number of species in a given area
Blooms Taxonomy: Understand
1.3
1.3 Assessment: Summarize the
characteristics of all living things

Living things are made up of basic units called
Cells
___________,
are based on a universal
Genetic Code obtain and use materials and
________________,
Grow
Energy
_______________,
_____________and
_____________,
Develop
Environment
______________,
respond to their ________________,
Reproduce
maintain a stable internal environment, and
___________over
time
Change
Blooms Taxonomy: Remember
1.3
1.3 Assessment: How do the characteristics of
living things contribute to an organisms’ survival

The cells that are the basic unit of life carry out the functions needed
to support and maintain life, for which they require a continuous
supply of energy.

The ability to respond to the environment helps an organism to avoid
injury and death, as well as meet material needs.

Reproduction and development enables species survival.
Blooms Taxonomy: Analyze
1.3
1.3 Assessment: Describe the relationship
between cells and organisms

All organisms are made of 1 or more cells

Cells are the functional units of life

Cells carry out the activities that support life
Blooms Taxonomy: Understand
1.3
1.3 Assessment: How does biodiversity depend
on a species ability to reproduce?

Without the ability to reproduce a species would become extinct,
which would lead to a decrease in biodiversity.
Blooms Taxonomy: Analyze
1.3
1.3 Assessment: Why is homeostasis
essential for living things?

It enables organisms to survive in diverse and changing environments.
Blooms Taxonomy:Apply
1.3
1.3 Some opponents of the theory of evolution dismiss the
ideas as being “just a theory.” Why is this NOT a very
good argument against the theory of evolution?

Saying that an idea is “just a theory” implies that the idea is just a
hunch. Scientific theories like evolution are much stronger than a
hunch—they are well-tested and well-accepted explanations
supported by a large body of evidence.
Blooms Taxonomy: Evaluate
1.3
1.3 Which characteristic of living things is important to the
survival of a group of animals rather than an individual
member of this group? Why?

Reproduction is important to maintaining a group of animals.

An individual member of the group can survive without reproduction,
but the entire group would die out if none of its members reproduced.
Blooms Taxonomy: Evaluate
1.3
1.3 What are some ways in which all living
things are similar at the molecular level?

all organisms are made of cells, which are built from a common set of
chemical building blocks;

all organisms store information in a common genetic code;

all organisms use proteins to build their structures and carry out their
functions.
Blooms Taxonomy: Evaluate
Unifying themes connect
concepts from many
fields of biology
1.3
1.3 Objectives:

Identify four major Unifying Themes/ Big Ideas in biology
1.3
CH1.3 Vocabulary
Homeostasis
Dynamic
DNA
Natural selection
Metabolism
Chromosome
Evolution
Universal Genetic Code
Heredity
Adaptation
Negative Feedback
Positive Feedback
1.3
4 Big Ideas in Biology

Big Idea 1: The process of evolution drives the diversity and unity of life.

Big Idea 2: Biological systems utilize energy and molecular building blocks
to grow, to reproduce and to maintain dynamic homeostasis

Big Idea 3: Living systems store, retrieve, transmit and respond to
information essential to life processes.

Big Idea 4: Biological systems interact, and these systems and their
interactions possess complex properties.
1.3
Big Idea 1: Evolution explains the unity
and diversity of life.

Evolution is the change in populations of living things over time.

The genetic makeup of a population of a species changes.

Evolution can occur through natural selection of adaptations.

Adaptations are beneficial inherited traits that are passed to future
generations through DNA.
1.3
Big Idea 1: Evolution explains the unity
and diversity of life

Behaviors and adaptations can help maintain homeostasis

Adaptations include any heritable trait, behavior, or
characteristic that increases an organisms ability to survive
and reproduce in their environment

See Why Chimps Don’t Play Baseball
https://www.youtube.com/watch?v=Jq6dCFCMGq4
1.3
Big Idea 2: Biological systems utilize free energy and
molecular building blocks to grow, to reproduce and to
maintain dynamic homeostasis

All levels of life have systems of related
parts.

A system is an organized group of
interacting parts.

A cell is a system of chemicals and
processes.

A body system includes organs that
interact.

An ecosystem includes living and nonliving
things that interact.
1.3
Big Idea 2: Biological systems utilize free energy and
molecular building blocks to grow, to reproduce and to
maintain dynamic homeostasis

Living systems require energy and matter to maintain order, grow and
reproduce.

Organisms employ various strategies to capture, use and store energy

Organisms also have feedback mechanisms that maintain dynamic
homeostasis by allowing them to respond to changes in their internal and
external environments.

Negative feedback loops maintain optimal internal environments

Positive feedback mechanisms amplify responses.
1.3
Big Idea 2: Homeostasis is usually maintained through feedback
mechanisms
1.3
Big Idea 3: Living systems store, retrieve, transmit and
respond to information essential to life processes.


Genetic information provides for continuity of life and, in most
cases, this information is passed from parent to offspring via
DNA

Heritable information is packaged into chromosomes that are
passed to daughter cells.

Genetic information contains instructions necessary for the
survival, growth and reproduction of the organism.

Genetic variation is almost always advantageous for the longterm survival and evolution of a species
To function in a biological system, cells communicate with
other cells and respond to the external environment.
1.3
Big Idea 4: Biological systems interact, and these
systems and their interactions possess complex
properties.

All biological systems are composed of parts that interact with each other.

These interactions result in characteristics not found in the individual parts
alone.

In other words, “the whole is greater than the sum of its parts.” All biological
systems from the molecular level to the ecosystem level exhibit properties of
biocomplexity and diversity.

Biologists study many different interacting systems
1.3
1.3 Assessment: What is Evolution

Evolution refers to changes in the genes of a population over time

Because genes code for traits, populations will also change their
traits/ adaptations over time
Blooms Taxonomy: Remembering
1.3
1.3 Assessment: What is meant by the term
“Natural Selection”

Natural Selection is the gradual process by which traits become either
more or less common in a population due to differential reproductive
success of organisms interacting with their environment
Blooms Taxonomy: Understand
1.3 Assessment: What is the relationship
between adaptations and natural
selection?

1.3
Natural selection leads to different adaptations in different
environments.
Blooms Taxonomy: Alanyze
1.3
1.3 Assessment: How is the process of
natural selection involved in evolution?

Natural selection is one of the leading causes of evolution.

It refers to the process by which some adaptations are more
advantageous and so become more prevalent in a population over
time.

Different adaptations in different environments can lead to new
species
Blooms Taxonomy: Analyze
1.3 Assessment: Give an example of an
adaptation that’s helpful in 1 environment
but would be harmful in another

1.3
Thick polar bear fur is helpful in cold environments but wouldn’t be
very good in hot ones
Blooms Taxonomy: Creating
1.3
1.2 Assessment: How are structure and
function related to adaptations?

An adaptation is a genetic change that can affect the structure of
some aspect of an organisms body and how well it functions in a
given environment.
Blooms Taxonomy: Analyze
1.3
1.3 Assessment: Homeostasis is said to be both
“stable” and “dynamic” How can it be both

Homeostasis refers to maintaining an stable internal environment,
regardless of what the outside environment is like.

Because the outside environment changes, the internal environments
must also change in order to be stable.

Example: Normal body temperature is 98.6 degrees, but the body has
different processes to maintain that depending on the temperature of
the environment

When its hot out, you may sweat

When its cold out you may shiver
Blooms Taxonomy: Analyze, Evaluate
1.3
1.3 Assessment: Can you think of a time when in
order to maintain homeostasis your body
deviates from 98.6 degrees?

Sometimes when you are sick you get a fever which increases your
body temperature
Blooms Taxonomy: Apply
1.3
1.3 Assessment: Feedback loops are used to
maintain homeostasis

When women give birth they release a hormone called oxytocin that
causes the uterus to contract and push the baby out. Every time the
uterus contracts, more oxytocin is released, causing the contractions
to get stronger and occur more frequently. Is this an example of
negative feedback or positive feed back? Explain
Positive Feedback, because the response amplifies the initial stimulus
Blooms Taxonomy: Apply