Transcript Biology I Mrs. Schalles

Biology
Mrs. Schalles
Chapter 1
The Science of Life
Most notes & images in this show from HOLT Biology text unless noted otherwise.
Image from: http://www.le.ac.uk/bl/background2.jpg
Most topics that will be covered in
Biology are introduced in chapter 1
I. The World of Biology
A. Branches of Biology
B. 7 Characteristics of Living Things
II. 3 Themes in Biology
A. Unity of life’s: Genetic Code & Classification
B. Interdependence: Environment & Ecology
C. Evolution: Darwin, Natural Selection,
Adaptations
III. Scientific Method
IV. Tools & Techniques:
Microscopes & Other tools
Biology- the study of living things
Biologists study life
on many levels- from
molecular to global.
We are beginning to solve puzzles- how does a single cell
grow into a multicellular plant or animal, how the human
mind works, how solar energy is converted into chemical
energy- food, how organisms network in biological
communities like coral reefs, what threatens life
I. The World of Biology
A. Definitions
1. Biology- the study of life
“bio” means “life,
“-logy” means the study of.
2. The branches of Biology
-something in the vast field of biology
interests you & is important to your life.
-Biologists study the food supply,
microorganisms, plants, health, ecology,
biochemistry & more.
We’ll look at some of the many fields of biology.
Branches of Biology
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Anatomy- study of body parts
Botany- study of plants
Bacteriology- study of bacteria
Cytology- study of cells
Ecology – study of environment
Embryology- study of development of
individuals
• Entomology- study of insects
• Horticulture-study of growing
• Immunology- study of immune system
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Genetics – study of genes & heredity
Hematology- study of blood
Herpetology- study of snakes
Microbiology – study of microorganisms
Mycology- study of fungi
Pathology- study of abnormal structures or functions
Parasitology – study of parasites
Paleontology- study of formerly-living
organisms like fossils and dinosaurs
• Physiology-study of body part functions
• Taxonomy- study of classification
• Virology- study of viruses
• Zoology -The study of animals
3. Organism- a living thing
• Oldest fossil of a living organism- over
3.5 billion years old
• Earliest Life on Earth-For millions of
years- only characteristics - unicellular,
aquatic, microscopic,
simple, anaerobic
(cannot live in oxygen)
B. 7 Characteristics of
Living Things
1. Organization/ Cell theory
2. Response to stimuli
3. Homeostasis
4. Metabolism
5. Growth & Development
6. Reproduction
7. Evolution
1. Organization/ Cell theory
Cell Theory – the theory that all living things
- are made up of one or more cells,
1. Cells are the basic units of organisms
2. In a multicellular organism - cells specialized!
3. Cells come only from existing cells.
-A cell is the smallest unit that can
perform all life’s processes.
Unicellular (single celled organism)
Multicellular (many celled organism)
Prokaryotic & Eukaryotic cells
Organization -is the high degree of order
within an organism’s internal & external
parts & its interactions with the world.
Hierarchy of organization of living things
• Atom
• Organic Molecule
• Organelle
• Cell
• Tissue
• Organ
• Organism
**See pages 6-7 of your textbook
“Emergent Properties”
• In the levels of the “hierarchy” there are
new characteristics that are not apparent
at a simpler level:
• Atom-Molecule-Organelle-Cell-Tissue-Organ-Organism
“A living organism is a whole
greater than the sum of its parts.”
(cannot fully explain a higher level of order by
breaking it down into its parts)
Cells are made of parts:
• Atoms: Carbon (C), Nitrogen (N), Oxygen (O),
Hydrogen (H), etc
• Molecules -made of atoms: water- H20,
Sugars like Glucose (C6H12O6), & large Proteins
like Hemoglobin, C738H1166N812O203S2Fe (amino
acids with a Fe ion) Phospholipids, DNA, etc
• Organelles -made of molecules: Nucleus,
Cell membrane, Chloroplast, Mitochondria,
Ribosomes, etc.
Atom-Molecule-Organelle-CellTissue-Organ-Organism
health.yahoo.com
www.scienceaid.co.uk www.answers.com
www.mie.utoronto.ca
www.search.com
Health.yahoo.com
web.jjay.cuny.edu
http://orchard.sbschools.net/library/links/body.jpg
7 Characteristics of Living Things
2. Response to Stimuli
• Stimulus– a physical or chemical change in
the internal or external
environment.
– that elicits or accelerates a
physiological or psychological activity
or response.
ebiomedia.com
• Response– Reaction to stimulus agent or
action
– For example: The owl dilates pupils in
the eye to keep the level of light
entering the constant.
www.birds.cornell.edu
B. 7 Characteristics of Living Things
3. Homeostasis
--The ability or tendency of an organism or cell
to maintain stable internal conditions
(equilibrium )by adjusting its physiological
processes.
-conditions such as: temperature, pH, water
content, uptake of nutrients by cells, etc.
will be maintained in a constant rangeusually different than outside environment.
Homeostasis Questions:
What would happen if:
-an amoeba could not maintain a
different internal amount of water
than it’s surroundings?
*It would explode with too much water
*It would shrivel up without enough water
-what if a desert mouse could not maintain a
different internal temperature than the
environment?
* freeze to death in cold night air
* bake in the daytime heat.
Quick Lab- page 8
Observing Homeostasis in Goldfish
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Read through the lab explanation.
I will select the lab groups.
Do not abuse the fish.
fish.dnr.cornell.edu
Be very careful with the glass thermometers; be
sure the temperature is the same as the labeled
beaker. Do not kill the fish. Wipe up any spills.
• Each person will hand-write a brief lab report (*see
lab report format- no cover page or references needed)
• Answer the 3 questions in the analysis section.
Quick Lab Results:
• Gills are a respiratory structure that consists of many
blood vessels surrounded by a membrane that allows
for gas exchange.
• It is protected by a hard plate called the operculum.
• The gills will move faster at higher temperatures.
• There is less dissolved oxygen in warmer water.
• The fish is taking in more water & therefore more
oxygen.
• The rate at which the gills move affects the
amount of oxygen- the amount of dissolved gas
in the fish blood. This maintains homeostasis.
B. 7 Characteristics of Living Things
4. Metabolism
–is the sum of all the chemical
reactions that take in and
transform energy and materials
from the environment.
B. 7 Characteristics of Living Things
5. Growth and Development
–Growth of living things results from
the division & enlargement of cells.
–Development is the process by
which an organism becomes a
mature adult.
B. 7 Characteristics of Living Things
6. Reproduction
• life must have ability to reproduce, no
organism lives forever.
• Living organisms pass on hereditary
information from parents to
offspring.
2 Types of Reproduction
1. Asexual Reproduction-one parent divides
into 2 identical offspring- EXAMPLES
– Binary fission -bacteria
– Budding -sponges -fungi like yeasts
– Regeneration- earthworms
Advantage- don’t need mate;
Disadvantage- no genetic variations
2. Sexual Reproduction- 2 parents combine
genetic info to form a unique individual
-Egg of a female & sperm of a male form a
ZYGOTE- info from both parents
Cell Reproduction:
Mitosis & Meiosis
There are 2 kinds of cell division in eukaryotic cells:
• Mitosis occurs in cells for
growth, development, repair
or asexual reproduction.
• Meiosis occurs during formation of gametes
for sexual reproduction
www.ccs.k12.in.us/.../Humanembryology.htm
Reproduction
An interesting organism: Volvox
• Common colonial algae
• Reproduces- asexually & sexually!
• Asexual- 1 parent cell simply splits
into 2 identical “daughter” cells
• Sexual reproduction:
The dark spheres are egg
-cells. They are fertilized
by small packages of sperm.
Reproduction & Inheritance
Some important terms:
• DNA molecule– deoxyribonucleic acid
– has “how to” info
• Gene- a segment on DNA macromolecule
- may be 100s of genes on a DNA strand
- codes for a specific trait (like eye color)
• Inheritance - traits passed from parent to
offspring
B. 7 Characteristics of Living Things
7. Change over Time (Evolution)
– Populations of living organisms
evolve or change through time.
-Evolution- from “evolve” meaning to
change.
II. 3 Themes in Biology
A. Unity of life’s Diversity
-Life is diverse yet shares unity in molecules -
DNA & genetic code
B. Interdependence of Organisms
-organisms interact with biotic & abiotic
factors
C. Evolution - theory that organisms
change over time, the driving force is the
environment.
DNA
The Genetic code
- all life has hereditary
information in DNA
–DNA molecules
(Deoxyribonucleic acid)
-Double helix - shape is formed
by nitrogenous base pairs
attached to a sugarphosphate backbone.
“Unity of Life’s Diversity”
• Taxonomy: the classification of
organisms
• Tree of Life: shows that all living
things have descended with
modification from a single common
ancestor
Phylogenic Tree
• Shows relationships:
• between 3 Domains & 6 Kingdoms
Taxonomic Classification:
• 3 domains: Bacteria, Archaea, and Eukarya.
• 6 Kingdoms: Archaea, Bacteria, Protista,
Fungi, Plantae, and Animalia.
• Further divided into smaller Taxonomic groups:
– phyla
– class
– order
– family
– genus
– species
3 Domains
1. Archaea -Prokaryotic cells
(unicellular)
-little understood, recently discovered life
-probably oldest cells & found in extreme environments
KINGDOM– Archaea
2. Bacteria = Prokaryotic cells (unicellular)
-all the common bacteria, both good & bad
-KINGDOM—Bacteria
3. Eukarya = Eukaryotic cells
(have a nucleus)
There are four kingdoms in Eukarya
* Protista
* Fungi
* Plantae
* Animalia
6 Kingdoms- examples
Archaea,
www.ucmp.berkeley.edu
Fungi,
Bacteria,
www.dph.state.ct.us
Plantae,
Protista,
www.microscopy-uk.org.uk
Animalia.
www.wetwebmedia.com
danny.oz.au
usmo4.discoverlife.org
usuarios.lycos.es
II. 3 Themes in Biology
B. Interdependence
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Ecology- How organisms interact with both
other organisms & the environment.
1. Biotic Factors – living organisms
2. Abiotic Factors - non-living part of the
environment (water, temperature, soil type,etc)
3. Ecosystems- Communities of different
living species (Biotic factors)& interact with
each other & their non-living environment
(Abiotic factors).
Ecology
• Is the study of how
organisms interact
with each other and
their physical environment.
• Environment – everything- biotic
& abiotic- surrounding an organism
In ecology we will study:
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Trophic levels in the food chain
The Biosphere
Population growth, limiting factors
Species interactions: Predation,
competition, parasitism, Mutualism &
Commensalism
Successional changes in communities
Major Biomes of the world
Use of resources, pollution
Watershed & Wetlands
Energy Relationships
-study how organisms get,
use & transfer energy
• Sun- Source of almost all energy
• Autotrophs- Organisms that make their
own energy (food) (photosynthesis)
• Heterotrophs – Organisms that obtain
energy by eating other organisms
Food Chain & Food web in an
Antarctic Ecosystem
All food chains must start with a
producer (autotroph)!!!
What is the difference between a food chain & a food web?
Note numbers of organisms:
Chart: many times more producers than large carnivores
BIOSPHERE
• the thin layer of Earth’s crust, atmosphere
& ocean layers that supports LIFE
• includes:
– All plant and animal life
– Air, soil and water.
– A variety of ecosystems that
As far as we know so far - we are
the only life in the universe…
Are we alone?
Earth Age: About 4.5 Billion Years Old
Location: In the Solar System, on the outer
edge of the Milky Way, about 28,000 light years
from the galactic center
Life in the Biosphere- 3 parts:
• ATMOSPHERE – light blanket of air enveloping
the earth, with more than half its mass within 4 miles of
the surface and 98% within 16 miles
• HYDROSPHERE --- the surface & subsurface
waters in oceans, rivers, lakes, glaciers, groundwater
• LITHOSPHERE --- upper earth's crust containing
the soils that support plant life, the minerals that plants
and animals require for life and the fossil fuels and ores
that humans exploit.
Hydrosphere:
• Surface Data:
• 70% of earth is covered by water
• Remaining 30% - 7 continental land masses.
• Water Composition:
• 97% salt water,
• 3% fresh water
– 2% glaciers/ice
– only.3% usable!
Atmosphere:
• Air Composition:
– 78% nitrogen,
– 21% oxygen,
– 1% other
• Atmosphere
Layers:
– Trophosphere
– Stratosphere
– Mesosphere
– Thermosphere
– Exosphere
LithosphereEarth Layers:
Inner core- solid
Outer core- liquid
Mantle- solid
Asthenospheremolten like
playdough
Lithosphere- solid
• Includes the crust, is very thin
• Fragmented into tectonic plates which move.
• Plate movement is called plate
tectonics.
Ecology Levels of Organization
• ORGANISM -Simplest Level (1 living thing)
• POPULATION- All the members of the same
species - that live in one place at a given time &
make-up a breeding group.
• COMMUNITY- Includes all the interacting
populations in one area.
• ECOSYSTEM- Includes all the living (biotic) &
non-living (abiotic) factors in the environment.
• BIOSPHERE- Thin layer of life around earth.
Levels of Organization
A Changing Environment
• Abiotic Factors do not remain constant
• Organisms able to survive a range of conditions,
both natural cycles & manmade change
• Most individuals can survive average conditions
Environmental Concerns
-what are causes of pollution & where does it end up?
Watersheds
• A watershed is the
area of land where
all of the water
that is under it or
drains off of it
goes into the
same place.
Watersheds come in all shapes
and sizes.
• They cross county, state, and national
boundaries. No matter where you are,
you're in a watershed!
• In southwestern PA- our water drains
first in to small creeks, then into the
Monongahela river, then into the Ohio
River & then the Mississippi River &
ultimately the Gulf of Mexico.
Mississippi Watershed
Pollution that is added to water
upstream will end up thousands
of miles away.
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Oil dripping from you car
Salt & chemicals on the roadways
Pesticides sprayed on your grass
Cleaners washed down your sink drain
Garbage dumped into the environment
Toxic discharge
Scientists in Oregon & Washington States speculated that water
discharged from a lake pumped almost dry by farmers has
contributed to the toxic blue-green algae bloom that killed fish in
this river. Dead blue gills, carp and frogs were readily visible in the
water, which flows directly to the Tualatin River.
More fish die from a lack of
oxygen than any other cause
• Algae blooms -from pollution
• Stagnant water
– from building dams or other construction
– cause growth of micro-organisms that use up all the
oxygen & build up of undesirable chemicals,
especially nutrients and heavy metals.
• Also- Artificially warm water from industrial use
• Remember: Warm water holds less
oxygen than cool water
Pennsylvania Fishes
• Note natural environments/ oxygen needs for local fish:
•http://sites.state.pa.us/PA_Exec/Fish_Boat/pafish/fishhtms/chapindx.htm
Municipal Solid Waste:
An average person may
produce a ton of refuse in a year
• a volume that rapidly overflows local dumps.
A Modern Landfill
Problems with Landfills
• Full- Many landfills are almost at capacity.
• “NIMBY”- where do we put new landfills???
• Leaks:
–Leachate- a liquid that has formed as
water leaks through compacted waste in a
landfill.
–Methane Gas -highly explosive,
flammable gas formed as organic matter
decomposes.
(3rd Theme in Biology)
C. Evolution
1. Theory that organisms change over
time, the driving force is the environment.
2. Natural Selection- process by which
adaptation is passed on to the next
generation for best survival.
3. Adaptations-are favorable traits
-Ex.- cactus plants
adapted to desert
Science & Religionin answer to your questions:
• Occasionally, the media may report on the
“conflict” between religion & scienceimplying that one must “choose” – or that
science has “replaced” religion.
• For most there is no conflict! Many
famous scientists were Christians who used
their Judeo-Christian belief in a rational God
as the foundation for their study.
• Even Evolution is NOT contrary to personal
faith.
Charles Darwin• English naturalist
who presented
compelling evidence
that all species of
life have evolved
over time from
common ancestors,
through the process
he called natural
selection.
http://oreh.pef.uni-lj.si/~markor/Darwin/Charles_Darwin.jpg
Darwin’s trip around the world on the
H.M.S.Beagle, especially the stops in
South America & the Galapagos
Islands were the basis for his work.
Darwin saw unusual things on his
voyage & tried to explain them:
• Strange Fossils
• Large tortoises
• Many kinds of
beaks on finches
http://www.thisviewoflife.org/evolution/finch.jpg
www.break-fresh-ground.com
Summary: 4 Main Parts of
Darwin’s Reasoning
• 1. Overproduction- more offspring are
produced than can survive
• 2. Genetic Variation- within a population,
individuals have different traits
• 3. Struggle to Survive- individuals must
compete with each other to exist.
• 4. Differential Reproduction- Organisms
with the best adaptations to environment more
likely to survive & reproduce.
Chapter 154 Main Parts of Darwin’s Reasoning
Natural Selection
A simple example of
Natural Selection
- tiny fish may be able to hide under
rocks and not get eaten by a predator
- next generation has fewer large fish,
“nature” has selected for smaller fish
in that pond
Biology Terms: Extra Info that you will need to know
Terms about Structure & Function
• Morphology – the structure and form
of an organism
• Anatomy – the branch of morphology
that deals with internal structure
Structure is almost
always related to
function.
Example- Bird beaksshape shows how
it gets food
Science & Society
• Applied Science- knowledge from biological
science can be used to improve human life
• Bioethics – The study of what is right or wrong
as it applies to biological concerns.
• Biotechnology- technology based on biology,
especially when used in agriculture, food science,
and medicine
– genetic engineering, & DNA Technologymaking new forms of life by transferring genes from
one organism into another- like inserting gene for
enzyme Chymosin -from the stomach of calves
into the DNA of both bacteria and yeasts-
Biotechnology:
Genetically engineered cheese
–cheese
is now cheaply made
- with genetically modified yeast chymosin,
(an enzyme which curdles milk, found in calves, who
drink milk, but not in normal yeast!)
Genetic Medical Applications
• Making medicine- until recently- medicine
had to be collected from plants or made from
chemicals. Now can make body substances like
human blood clotting factors, insulin, vaccines &
(HGH) HumanGrowthHormone with GM bacteria.
• Making body parts- may be able to clone
cells & make new organs so that no rejection
occurs. May be able to grow new human liver in
another organism like a pig.
• May also be able to screen for diseases, create
“designer babies”, cure cancer.
Gene Therapy
• Example: replace or repair
faulty gene for cystic fibrosis.
• Insert a copy of good gene from
healthy person into virus.
• Infect patient’s lungs with virus,
virus delivers good gene. Now
patient can make the right protein
to stop accumulation of mucus &
can breathe normally.
Imagine being this mother of child with CF,
Daily you must massage & loose mucus.
Any cold could overwhelm & cause death.
Now imagine what gene therapy represents.
Examples: Featherless chicken
• a controversial featherless
chicken which they say is
faster growing.
• will not need to be
plucked, saving money in
processing plants.
• they would not be suitable
for cooler countries,but OK
in hot climates
• There was a rumor that
KFC uses these already but
it is not true.
http://news.bbc.co.uk/1/hi/sci/tech/2000003.stm
Fishy Strawberries
Flounder is a fish that can withstand
icy cold temperatures.
Scientists took the gene in the fish that
Produces an antifreeze & inserted it into
a plasmid of a bacterium
The bacterium infected the strawberry &
the flounder antifreeze gene entered the
strawberry’s DNA
The new GM strawberry cells are grown
Into new plants that have strawberries
which make a protein that keeps the fruit
from frost damage.
www.usbornequicklinks.com
GM foods- Golden Rice
Golden Rice is part of the solution
to world hunger & malnutrition.
-Biofortified rice may alleviate life-threatening
micronutrient deficiencies in developing
countries-(decrease starvation)
- Genetically modified- gene for
provitamin A (β-carotene), is inserted
into rice genome.
www.goldenrice.org/
All living things have the same
genetic building blocks
DNA- deoxyribonucleic acid
has 4 nitrogenous bases which make
up the “alphabet” for the genetic
code.
SO- the same sequence of DNA
(gene) codes for an enzyme, a
protein or other molecule no matter
which organism that gene is in.
That is the basis for Gene technology
Biotechnology
• There is currently much debate among
scientists, politicians & environmentalist
about the safety & quality of genetically
modified products, especially foods.
• It is very likely that you have already eaten
multiple products that were produced with
biotechnology and/or DNA technology
III. The Study of Biology
A. The Scientific Method Steps:
1. Observation
2. Hypothesis
3. Prediction
4. Experiment
5. Data Analysis/ Conclusions
6. Communication/ Verification
B. Evaluating Bias- at times, scientists have
conflicts of interest. A scientist’s goal should be
finding facts, not support of government agency
agenda or the desired results of a pharmaceutical
company.
Remember: Experiment terms
– Control group provides a normal standard against
which we compare results of the experimental group.
– Experimental group is identical to the control
group except for one factor.
–Variables:
factors that change
–Theory -a set of related hypotheses confirmed to be
true many times
– An advantage of the scientific
method is that it
is unbiased & repeatable.
IV. Tools & Techniques
A. Microscopes
1. Types of Microscopes
*Compound light microscope
-shines light through a specimen
(must have thin slice of object)
-uses 2 lens to magnify image.
*Electron microscope
-SEM (scanning electron microscope)
-TEM (transmission electron microscope)
2. The parts of the Microscope- see hand out
Compound microscopes
Used to magnify thin slices of specimens
www.slic2.wsu.edu
Magnification with each lens
• TOTAL MAGNIFICATION=
low power magnification X eye piece magnification
• The eyepiece is 10X
• Low power is 4X
• Other lens may vary- usually
- 10X
- 40X
Microscope Use:
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Carry the microscope with 2 handsBy the “arm” & one hand under the base
Look through eyepiece & keep both eyes open
Place the slide that you want to view over the aperture
and gently move the stage clips over top of the slide to
hold it into place.
• ALWAYS begin use & focus with the
*Microscope on LOW Power (4X) !!!!
*Make sure the stage is all the way down.!!!!!
• Always Begin focusing with the coarse adjustment
Light Microscopes
–The eyepiece magnifies the image.
–The objective lens enlarges the
specimen.
–The stage is a platform that
supports slides with specimens.
–The light source is a light bulb that
provides light for viewing images.
Magnification & Resolution
–Magnification is the increase of an
object’s apparent size.
–Resolution is the power to show
details clearly in an image.
Figure 1. Relative Size of Microbes.
E.M. refers to the Electron Microscope.
www.slic2.wsu.edu
Object Size and Magnifying
Power of Microscopes
B. Other tools
• Centrifuge-spinning separation of materials in a liquid
that have different densities
• Autoclave – heating chamber to disinfect
• Chromatography -is any technique that separates
different substances based on their chemical or physical
properties
• Electrophoresis - is a technique for separating
particles that have an electrical charge.
• Spectrophotometer -determines what a substance is
by measuring the amount of each wavelength of light
absorbed by the sample.
• Computers are one of the most important tools used in
biology studies.
http://www.chs.k12.nf.ca/science/b2201/WebCT-Copy/units/unit1-02.htm
Electron Microscopes
– Scanning electron microscopes pass
a beam of electrons over the specimen’s
surface for better viewing the external
surface of a specimen.
– Transmission electron microscopes
transmit a beam of electrons through a
thinly sliced specimen for better viewing
the internal structures of a specimen.
C. Units of Measure
• SI Units
– Scientists use a single, standard system of
measurement, called the metric system. The
official name of the metric system is Système
International d’Unités or SI.
Questions
Which of the following is the hereditary
material in most living things?
F. DNA
G. lipids
H. oxygen
J. carbon dioxide
Questions
. Which of the following does evolution help
explain?
A. how organisms reproduce
B. how organisms grow and develop
C. how organisms are related to each
other
D. how organisms obtain and metabolize
energy
Questions
Which of the following does the hierarchy of
organization within an organism describe?
A. metabolism
B. homeostasis
C. internal structures
D. relationship to the physical environment
Questions
To which of the following does the resolution
of a microscope refer?
F. its ability to show detail clearly
G. its power to scan the surface of an
object
H. its series of interchangeable objective
lenses
J. its power to increase an object’s
apparent size