Transcript CHAPTER 1

WARM UP “WHAT IS LIFE?”
HOW DO WE DEFINE LIFE?
1.
(1 minute) Make your own definition…write it down
2.
(2 minutes… 1 each) Share it with your partner. Also use
the time to learn e/o’s names, and something you do
that makes you feel very alive.
3.
Read “What is Life?”. Underline key points. Answer
questions 1-3.
4.
When finished discuss your answers w/ your partner.
(save this for later… we’ll continue part-way into the lecture.)
CHAPTER 1
Ten Themes in
the Study of Life
Ten themes in Biology:
1.
Emergent Properties
2.
The Cell
3.
Heritable Information
4.
Structure-Function
5.
Interaction with the Environment
(interdependence/energy transfer)
6.
Regulation
7.
Unity and Diversity (continuity &
change)
8.
Evolution
9.
Scientific Inquiry (science as a
process)
10.
Science, Technology, and Society
WHY USE THEMES???
 Large volume of vocabulary & facts. Themes
help make connections.
 scales of size and time vary greatly. Themes
apply to life on many levels- microscopic to
whole systems.
 Themes are core principals that cut through
the material… no matter what topic you are
studying they can be applied =
OVERARCHING CONCEPTS
Paul Sereno, paleontologist
Flossie Wong-Staal,
HIV researcher
Joanne Chory. Plant Biologist
George Langford, Cell Biologist
4 BIG IDEAS combine themes
1. The process of evolution drives the diversity
and unity of life.
2. Biological systems utilize free energy and
molecular building blocks to grow, to
reproduce, and to maintain dynamic
homeostasis.
3. Living systems store, retrieve, transmit, and
respond to information essential to life
processes.
4. Biological systems interact and these systems
and their interactions possess complex
properties.
4 minute BRAINSTORM
then discuss w/ your partner
QUESTIONS TO CONSIDER:
 What do you think each idea means?
 Can you provide an example of each?
 Which characteristics of life apply to each big
idea?
1) EMERGENT PROPERTIES
 REDUCTIONISM is a “top down”
approach used to understand the
nature of complex things by
reducing them to
 1. Simpler more fundamental parts. Or
 2.
the interactions of their parts.
 Looking at life “bottom up”, ORDER
(a high degree of it) is a basic
characteristic of life, at any level...
 Each level, ATOM to the BIOSPHERE, is
organized.
 Properties result from interactions
between the components.
 At each larger level unique properties
“emerge” or appear.
Ex. LIFE only exists at the level of CELL,
which is made of organelles, etc..
HIERARCHY OF ORGANIZATION
each level builds on the levels below
it…
can you put these in order small to big?
Multicellular
Organism
Cell
Atom
Molecule
Biosphere
Organelle
Chemical
building block
Biome
Organ system
Macromolecule
Community
Organ
Population
Tissue
Ecosystem
HIERARCHY OF ORGANIZATION
smallest components of living things
to the largest groupings of them.
1. atom
2. molecule
3. Chemical
building block
4.
Macromolecule
5. organelle
6. cell
7. Tissue
8. Organ
9. Organ system
10. Multicellular
organism
11. population
12. community
13. ecosystem
14. biome
15. BIOSPHERE
Bioverses???
THE TOTAL IS GREATER THAN
THE SUM OF IT’S PARTS.
Life is more than just the atoms, molecules, & cells
that compose it…
there are also properties/qualities/characteristics
that “EMERGE” because of interactions.
The phenomena of evolution occurs because of
interactions of organisms and their environment
through differential reproduction- only at the
level of POPULATION.
How do we define Life? A collection of characteristics.
All PROPERTIES (characteristics) emerge at the final “level”
of LIFE- the CELL (in the cells of these multicelled creatures)
What characteristics/properties of life do you observe?
SOME PROPERTIES OF LIFE
How do we define Life?
All PROPERTIES emerge at the final “level” of LIFE.
Nonliving things may have some of these propertiesbut only living things have ALL of them.
 M
 R
 S
 C
 H
 O
 G
 E
 D
Characteristics of living things

Metabolism (chemical reactions that utilize matter & energy)

Reproduction (by copying & transmitting DNA)

Sensitivity (responds to stimulus)

Cells (the basic unit of life)

Homeostasis (maintains a steady state)

Order & complexity (much more complex than nonliving things)

Growth & development (based on DNA)

Evolutionary Adaptation (changes that accumulate over
generations)

DNA (Deoxyribonucleic Acid- the molecule of heredity)
Metabolism
Energy Utilization
(Adaptation)
reproduction
ORDER
Growth and Development
 Basically, Life is defined by a collection of
qualities or characteristics. MRS CHOGED
 WHAT IS LIFE? Activity/ Warm UP continued
Pick 5 specimen to observe. For each
specimen check off the characteristics it
has. Analyze your findings 4-13.
 If the specimen is living it should have a check
by all of them.
 If the specimen does not have checks for all it is
either inanimate or dead
 Dead things still have: cells, DNA, order, &
physical evolutionary adaptations.
2) Cells… basic unit of life
THE CELL THEORY (schleiden, schwann, virchow)
1) All living things consist of cells.
2) Cells are an organism’s basic unit of structure and
function.
3) All cells come from other cells.
 Hooke (1665) English, observed cork- dead plant
material, 30x, “cells”
 Leeuwenhoek (Dutch), observed pond water, 300x, 1st
living cells “animacules”, protists, sperm, blood
 (1839) Schleiden & Schwann- German, The cell is the
universal unit of life.
 Virchow (1855) German, “Omnis cellula e cellula.”…
“Every cell originates from another cell.”
Cell Types: (there are two)
1)
Prokaryotic cells
- ex. bacteria & archaea
2)
Eukaryotic cells
- ex. all other life forms
 Similarities: both have DNA and are enclosed by a membrane.
 Differences: Eukaryotic cells are larger and have internal
membranes which divide the cell into functional compartments
called “organelles”-
 ex. The nucleus in the membrane around the DNA.
3) Heritable
Information
DNA (deoxyribonucleic acid)
 is the substance of genes- instructions to make
protein and protein makes the creature what it is.
 Units of inheritance passed from parents to
offspring.
 Double stranded molecule made of 4 chemical
“letters” or nucleotides (ATGC).
 Human genome is 6 billion “letters” long in 23
pairs of chromosomes.
The genetic material: DNA
4) Structure Relates to Function
 Form (structure) fits
function (job) & vice
versa.
 Ex. Nerve cells are
shaped differently than
skin cells- allows for rapid
communication.
 Bird bones shaped to be
lighter than those of
reptiles or mammalsallows for flight.
Form fits function
Andreas Vesalius
 1514-1564 was a
Flemish anatomist
and author of one of
the most influential
books on human
anatomy,De humani
corporis fabrica (On
the Workings of the
Human Body).
 Founder of modern
human anatomy.
 There is an Anatomy
& Physiology (H/R)
class taught here at
• You do not
Pali.
have to
know this
for the test
FYIO
5) Interaction With Environment
 Organisms are open systems.
 Open systems exchange materials and energy with
their surroundings.
 Ecosystems are composed of living organisms and
their nonliving environment.
 Two main principles of Ecology:
1. Cycling/Recycling of nutrients from environment
to organisms (back) to relies on producers &
decomposers = biogeochemical cycles. ex. carbon
2. Flow of energy from sun to living organisms
through food chains and back to space as heat
from each link in the chain. ex. 10% rule
The Nitrogen Cycle is one of the more complex biogeochemical cycles.
An introduction to energy flow and energy transformation in an ecosystem
6)Regulation
 Enzymes are protein molecules that regulate chemical reactions in cells.

These biological catalysts speed up reactions.
 Feedback loops self-regulate biological processes. A product of a
process regulates that same process

May stop or encourage the production of key enzymes.
 2 types:
1.negative feedback (insulin/glucagon- blood sugar)
A physiological control mechanism in which a change in a physiological
variable triggers a response that counteracts the initial change.
A primary mechanism of homeostasis.
2.positive feedback (oxytocin- uterine contractions)
A physiological control mechanism in which a change in a variable
triggers mechanisms that amplify the change.
Regulate blood sugar levels w/ this pair of hormones.
The production of each is controlled by negative feedback.
After a meal…
Insulin causes liver and muscle cells to take up excess glucose from your blood
and attach them together to make large glycogen polymers.
When blood sugar level is lowered your body stops making insulin.
Between meals…
Glucagon causes stored glucose to be released into your blood stream from
glycogen. When you have enough glucose, your body stops making glucagon.
Regulation by feedback mechanisms
Positive feedback speeds a process up. Snowball effect.
Examples:
1. Clotting of Blood- platelets release chemicals that attract more
platelets… so more chemicals are released… so more platelets
arrive… ENDS when scab forms- no more wound to attract platelets.
2. Baby pressure on uterine wall causes release of oxytocin, which
causes uterine contractions which causes more pressure on
uterine wall… and the production of more oxytocin… and so on
ENDS when baby leaves uterus- no more pressure on uterus.
7) Unity and Diversity
 “Vertical” dimension is the size scale reaching from
molecules to the bioshphere.
 “Horizontal” dimension stretches across the diversity
of life now and throughout life’s history (3.5 billion
years of history) includes extinct ancestors.
 1.5 million extant (living) species identified so far.
 Estimated 5-40 Million species to exist.
 Biodiversity is the measure of the number of
species and the abundance of each as well.
 species richness (zoo) vs. diversity (rainforest)
A small sample of biological diversity
TAXONOMY is the branch of biology that names and
classifies species. (Aristotle vs. Linnaeus) Organisms are
categorized into:
 Three DOMAINS of Life:
1. Bacteria- prokaryotes
2. Archaea- prokaryotes
3. Eukarya- eukaryotes
 Five or Six KINGDOMS of Life.
1. Animalia 2. Plantae
3. Fungi
4. Protista
(prokaryotes)
5. Monera
or
5. Archaea
6. Bacteria
Three domains of life
HOW DO YOU CLASSIFY LIFE
FROM GENERAL TO SPECIFIC?
 Linnaeus’ nested heirarchy.
Classifying life from most general to most specific
Kingdom
Phylum
Class
Order
Family
Genus
Species
Keep
Pots
Clean
Or
Family
Gets
Sick
Kinky
People
Come
Over
For
Group
Sex
King
Phillip
Came
Over
For
Good
Sex
An example of unity
underlying the diversity
of life:
the architecture of
eukaryotic cilia
Explain?
8)Evolution (core theme)
 Evolution is the core theme
of biology.
 Process that accounts for the
combination of unity and
diversity in life.
 Implies that all living things
are related.
 The common ancestors are
prokaryotes that existed 3.5
billion years ago.
TREE OF LIFE
 The organisms that
are alive today are
but the leaves of this
giant tree
 if we could trace their
history back down the
branches of the Tree
of Life
 we would encounter
their ancestors,\
 which lived
thousands or millions
or hundreds of millions
of years ago
Charles Darwin developed
The concept of
Natural Selection.
Observations:
a.) Individual variation.
b.) Struggle for existence.
Inference:
Differential reproductive
success.
Charles Darwin (1809–1882)
Diversification of finches on the Galápagos Islands
Differential reproductive
success was called
NATURAL SELECTION by Darwin.
Natural Selection does not
CREATE adaptations, it screens
variations that are heritable
In the next generation we see
a higher proportion of a trait.
Evolutionary adaptation is a product of natural selection
Weedy sea dragon
 Survival of the fittest- fitness is measured by
reproductive success.
 Inspired by Malthus- said that populations grow
faster than the resources to support them.
 Galapagos Islands- “new” land, off the west coast
of South America. Finches, tortoises, iguanas.
Careful observation and measurement provide the raw data for science
9) Scientific Inquiry… a search for information
and explanation often focusing on specific questions.
 TWO MAIN FORMS OF INQUIRY:
 1. Discovery Science
 describes natural structures and processes as accurately as
possible through careful observation and analysis of data.
Conclusions based on logic… “inductive reasoning”.
 Ex. microscope observations led to the CELL THEORY
 2. Hypothesis-Based Science
 Process of inquiry that includes repeatable observations and
testable hypotheses… “deductive reasoning” if… then statement.
 Science “to know” is limited to those structures and processes we can
observe and measure.
 Science can not answer questions like
“Why are we here?” … this is why the humanities are so important.
Applying hypothetico-deductive reasoning to a campground problem
If… then… reasoning
Works backwards from
The general to the specific.
Flashlight doesn’t work
If the bulb is the culprit
Then it should work w/ a
New bulb!
THEORY
 Comprehensive explanation supported by
abundant evidence.
 Idea that ties together observations and
experimental results that previously seemed
unrelated.
 Newton, Einstein, Darwin
 Gravity, Relativity, Natural Selection
Two examples of DNA technology
CNN bionic arm
10) Science, Technology
& Society
 Goal oriented applications of science.
 Ex. End world hunger- GMO’s super crops.
 Ex. End reliance on burning fossil fuels- Nuclear Power Plants
 Sometimes present new problems.
 Ex. Farmer’s rights, food allergies, invasive species, loss of diversity.
 Ex. nuclear waste disposal, accidents…
 Research feeds technology and vice versa.
Winter Reading: “The Immortal Life of Henrietta Lacks”
Class Discussion: Biotechnology PROS vs. CONS
HOMEWORK
1. Review your notes… answer the four outline
questions.
2. Skip, Skim over, or read carefully: chapter 2
CHEMISTRY.
3. Mandatory Reading & Cornell Notes/Flash
Cards- Chapter 3.
7 SCIENCE PRACTICES
The student can…
1. Use representations and models to communicate
scientific phenomena and solve scientific problems.
2. Use mathematics appropriately.
3. Engage in scientific questioning to extend thinking or
to guide investigations within the context of the AP
Course.
4. Plan and implement data collection strategies
appropriate to a particular scientific question.
7 SCIENCE PRACTICES
The student can…
5. Perform data analysis and evaluation of
evidence.
6. Work with scientific explanations and theories.
7. Connect and relate knowledge across various
scales, concepts and representations in and
across domains.
Table 1.1 Review of Ten Unifying Themes in Biology
Table 1.1 Review of Ten Unifying Themes in Biology (continued)