Download Biology - Down the Rabbit Hole

Biology
The Study of Life
What is Biology in the
21st Century?
How is studying Biology different
today than in the past?
How does studying Biology affect
your life? Why should you take
this class?
How has advancement in science
benefited humanity?
Course Topics
• Unit 1 – Nature of Science
• Unit 2 – Intro to Biology
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Biology 21st century
Chemistry of Life
Cell Structure
Classification and the Tree of Life
Biodiversity
Microscopes
• Unit 3 – Intro to Evolution
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Darwin and Natural Selection
Macro and Micro evolution
Systematic Taxonomy
Phylogeny
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History of Life
Organic molecules
Cell membrane transport
Energy Flow and thermodynamics
• Unit 5 – DNA Structure and Function
– Nucleic Acids
– DNA to Proteins
– Biotechnology
• Unit 6 – Reproduction and Development
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Mitosis and cloning
Meiosis
Sexual Reproduction
Comparative strategies
• Unit 7 – Genetics
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Mendelian inheritance
Chromosomes
Mechanisms of evolution
Speciation
• Unit 4 – Intro to Molecular Biology • Unit 8 – Ecology
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Populations
Ecosystems
Succession
Symbiosis
Behavior
Earth supports an
amazing diversity of life
biosphere = everywhere life exists
Earth supports an
amazing diversity of life
• Every part of the biosphere is connected with every other part.
• The biosphere includes many environments.
• Biodiversity increases at the equator and decreases toward the
poles
Earth supports an
amazing diversity of life
1.
2.
3.
4.
All levels of life have systems of related parts
Structure and function are interdependent in Biology
All life maintains homeostasis to survive in diverse
environments
Evolution explains the unity and diversity of life
• Nothing in Biology makes sense except in the light of evolution.
Earth supports an
amazing diversity of life
• A biological species is defined as a group
of individuals that will breed to
reproduce.
– Scientists have described over 1.7
million of the world's species of
animals, plants and algae, as of 2010.
• Mammals make up one of the smallest
groups, with just 5,490 members.
• Altogether the earth's oceans, lakes,
continents and islands support over
62,000 identified species of vertebrate
animals and 320,000 species of plants.
A small sample of biological diversity
Earth supports an
amazing diversity of life
• So...how many are there?
• According to a new report coauthored by Derek Tittensor at
UNEP's World Conservation
Monitoring Centre (UNEPWCMC), in Cambridge, UK, the
estimate is around 8.7 million.
– 86% of all species on land and
91% of those in the seas have
yet to be discovered, described
or catalogued.
All organisms share
certain characteristics.
• Biology is the scientific study of all forms of life
Life’s basic characteristic is a
high degree of order
• An organism is any
individual living thing.
– All are made of one or more cells.
What does all life have in
common?
– All are made of one or more cells.
– All need energy for metabolism.
– All respond to their environment.
– All have DNA that they pass on to offspring.
Properties of Life
cellular structure
Microscope
• Hooke (1665) English,
observed cork- dead
plant material, 30x,
“cells”
• Leeuwenhoek (Dutch),
observed pond water,
300x, 1st living cells
“animacules”, protists,
sperm, blood
Cell Theory
Schleiden Schwann Virchow
a)
b)
c)
All living things consist of cells.
Cells are an organism’s basic unit of structure and
function.
All cells come from other cells.
Metabolism Energy Utilization
Energy Flow
Sunlight
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Ecosystem
Producers
(plants and other
photosynthetic
organisms)
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Heat
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Chemical
energy
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Consumers
(including animals)
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Heat
Activities of life require
work
Work depends on sources of
energy
Energy exchange between
an organism and
environment often involves
energy transformations
In transformations, some
energy is lost as heat
Energy flows through an
ecosystem, usually entering
as light and exiting as heat
Respond to their environment
Interaction With Environment
and Energy Flow
Organisms are open systems
The dynamics of an
ecosystem include two
major processes
• Cycling of nutrients, in
which materials acquired by
plants eventually return to
the soil
• The flow of energy from
sunlight to producers to
consumers
reproduction
Heredity
The genetic material:
DNA
DNA (deoxyribonucleic acid)
• The substance of genesinstructions to make protein
and protein makes the
organism what it is.
• Units of inheritance passed
from parents to offspring.
• Double stranded molecule
made of 4 nucleotides
(ATGC).
• Human genome is 6 billion
nucleotides long in 23 pairs
of chromosomes.
Growth and Development
Unifying Themes in Biology
1. All levels of life have systems of related parts
2. Structure and function are interdependent in
Biology
3. All life maintains homeostasis to survive in diverse
environments
4. Evolution explains the unity and diversity of life
• Nothing in Biology makes sense except in the
light of evolution.
Biological organization is based on
a hierarchy of structural levels
The biosphere
Ecosystems
Organelles
1 µm
Cell
Cells
Atoms
10 µm
Communities
Molecules
Tissues
50 µm
Populations
Organs and organ systems
Organisms
SYSTEMS and
Emerging Properties
• Each level, ATOM to the BIOSPHERE, is organized.
• Unique properties are revealed at each level- they
“emerge”
• Properties result from interactions between the
components.
• “The total is greater than the sum of it’s parts”… a
hammer functions because of it’s head and handletogether.
• Example: Social interactions are affected by the
interaction of chemicals in the brain.
Form fits function
Homeostasis
Evolutionary Adaptation
Evolution
• Evolution is the core theme of biology.
• Evolution accounts for life’s unity and
diversity
• Implies that all living things are related.
• The common ancestors are prokaryotes
that existed 3.5 billion years ago.
Evolution
– unity: all species
descended from a
common ancestor
– diversity:
modifications that
evolved as species
branched from their
common ancestors
Unity in the Diversity of Life
• Underlying life’s diversity is a striking unity,
especially at lower levels of organization
• In eukaryotes, unity is evident in details of
cell structure
15 µm
Cilia of Paramecium
5 µm
Cilia of windpipe cells
Can you explain the
architecture of
eukaryotic cilia?
Is evolutionary adaptation a
product of natural selection?
• Thomas Malthus: organisms
will produce more offspring
than can be supported with
available resources.
• Survival of the fittest- fitness
is measured by reproductive
success.
Thomas Malthus (1766-1834)
• Many related organisms have
similar features adapted for
specific ways of life.
• Such kinships connect life’s
unity and diversity to
descent with modification.
• Natural selection eventually
produces new species from
ancestral species.
Darwin
The Concept of Natural Selection.
Observations:
a.)Individual variation.
b.)Struggle for existence.
Inference:
a.)Differential reproductive success.
b.)Evolutionary adaptation
The evolutionary view of life came into
sharp focus in 1859, when Charles Darwin
published On the Origin of Species by
Natural Selection
“Darwinism” became almost synonymous
with the concept of evolution
Charles Darwin (1809–1882)
Darwin
The Concept of Natural Selection
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The Origin of Species
articulated two main points
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Descent with modification
(the view that
contemporary species
arose from a succession of
ancestors)
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Natural selection (a
proposed mechanism for
descent with modification)
Adaptation
• Natural selection is often evident in adaptations of
organisms to their way of life and environment
• Bat wings are an example of adaptation
Diversification of finches on the Galápagos Islands
Scientific Inquiry
• Science “to know”
• Has limits – only what can be observed and measured.
• Can’t prove – only disprove
• Must be able to test (hypotheses)
• Experimental results must be repeatable
• Utilizes modeling to represent ideas
Scientific Inquiry
• Inquiry is a search for information and explanation,
often focusing on specific questions
• The process of science blends two main processes of
scientific inquiry:
– Hypothesis-based science attempts to seek natural
causes and explanations of observations
– Proposes a possible explanation and tests its
validity
– Discovery science describes nature through careful
observation and data analysis
– Example of discovery science: understanding cell
structure
Idealized version of
Scientific Process
Where does it begin?
– Observation is the active acquisition of
information from a primary source. In living
beings, observation employs the senses.
– Your assignment
• Observe the object at your table
• Use your senses to describe the object.
• In your notebook, write a minimum of one page
describing the object in front of you.
• You may not use the following terms in your writing
– Plant, flower, leaf, petal, stem, stalk
Theory
• Comprehensive explanation supported by
abundant evidence.
• Newton, Einstein, Darwin
• Gravity, Relativity, Natural Selection
• Idea that ties together observations and
experimental results that previously
seemed unrelated.
Science, Technology &
Society
• The goal of science is to understand natural
phenomena
• Technology applies scientific knowledge for
some specific purpose
• Research feeds technology and vice versa.
Data
• Data are recorded observations
• Two types
– Quantitative data: numerical measurements
– Qualitative data: recorded descriptions
• Inductive reasoning involves generalizing
based on many specific observation
Science is a
social process
Behavioralist Jane Goodall
recording observations on
chimpanzees
David Reznick conducting field experiments
on guppy evolution in Trinidad
Paul Serrano is digging into the past
Structure to function
Science, Technology & Society
Energy
Interdependence
Dilemma:
How to study Biology?
– something complex such as an organism or cell cannot
be analyzed without taking it apart.
– If you take something apart it disrupts the system and
interferes with the meaningful understanding of how it
works.
Dilemma:
How to study Biology?
• Systems Biology
– seeks to understand the behavior of a whole system rather
than its parts
– Seeks to create models of the dynamic behavior of whole
biological systems
– An example is a systems map of how proteins interact in a
fruit fly cell. The model may predict how a change in one
part of a system will affect the rest of the system.
Systems biology uses three
key research developments:
– High-throughput technology: methods to
generate large data sets rapidly
– Bioinformatics: using computers and software
to process and integrate large data sets
– Interdisciplinary research teams