Biology 160 Are we really what we eat?

• Today: Remember: print out and do Reading Guide 2, print

out and read Lab 01 - Microscopy Discussion Board assignment Scientists at work! Review from yesterday Scaffolding a model of the flow of matter Work on Reading Guide 01 in class: Understanding

how the diversity of our foods are all related through the diversity of life….

Group Project Part I

The difference between an observation and an inference

Observation Inference

A verifiable description or measurement

An educated guess basedon observations or prior knowledge

Could an inferencebe incorrect? How would you test it?

Scientists at Work!• Observations (looking carefully)

• Observed fibers, leaf veins, color, shape• I want to encourage you to take things apart, look more closely at

them, use all of your senses.

• Prior knowledge (experience)• Carbs come out of potato when you cut it• Unprocessed food is made of cells• Chicken meat has fatty tissue around it and may store toxins if not

organic• DNA found in nucleus of cells• Proteins make up the structure of cells

• Inferences (educated guess)• Carbs must be inside the potato cells• The molecules must make up the parts of the cells.• Marshmallows and lettuce are related because they both come from

plants.

What are we still wondering about our food?

• Go to class website and look at our “living notebook.”

Scaffolding a model of the Flow of Matter

See pictures of whiteboards…

Life in Its Diverse Forms Diversity is the hallmark of life.

• The diversity of known life includes 1.8 million species.

• Estimates of the total diversity range from 10 million to over 200 million species.

Biosphere

Ecosystem African savanna

Community All organisms in savanna

PopulationHerd of zebrasOrganism

Zebra

How is the diversity of our food related to the diversity of life?

• Get out your books and come pick up one Reading Guide 01 per person

• Please share your books in your group.• Although you will be working in groups, each person

is responsible for turning in their own reading guide.• You will have 30 minutes. Divide up the work as you

wish. Please be watchful of the time.• When you are done you can start work on Part I of

our Group Project until we come back together as a whole class.

Biology is the scientific study of life.

The Scope of Life

Life is structured on a size scale ranging from the molecular to the global.

Biology’s scope stretches across the enormous diversity of life on Earth.

Biosphere

Ecosystem African savanna

Community All organisms in savanna

PopulationHerd of zebrasOrganism

Zebra

Biosphere

Ecosystem African savanna

Community All organisms in savanna

PopulationHerd of zebras

Organ systemCirculatory system

OrganismZebra

OrganHeart

TissueHeart muscle tissue

Biosphere

Ecosystem African savanna

Community All organisms in savanna

PopulationHerd of zebras

Organ systemCirculatory system

OrganismZebra

OrganHeart

CellHeart muscle cell

TissueHeart muscle tissue

MoleculeDNA

AtomOxygen atoms

Cells!

The cell is the lowest level of structure that can perform all activities required for life.

• All organisms are composed of cells.

We can distinguish two major types of cells:ProkaryoticEukaryotic

The prokaryotic cell is simple, small, and contains no organelles.

The eukaryotic cell is larger and more complex and contains organelles.

The Three Domains of Life The three domains of life are:

• Bacteria • Archaea • Eukarya Eukaryotes

Prokaryotes

The Three Domains of Life

The three domains of life are:• Bacteria • Archaea • Eukarya

Prokaryotes

Eukaryotes

At least four kingdoms of Eukarya-Plantae-Fungi-Animalia-Protists (a group of multiple kingdoms)

Modeling the Flow of Matter

• In your groups again, grab a whiteboard and pens and work on Part I of your Group Project.

• We’ll take 10 min for this. Please watch the time.

• Remember: Don’t erase your whiteboards!

Am I Really What I Eat? continued…

• Next we’ll start to prepare ourselves to answer the question, “What does my food look like under the microscope?”

• On Thursday we’ll learn how to use a microscope in Lab 01

• On Tuesday we’ll look at our food more closely in Lab 02 using this revolutionary tool!