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Biology Mrs. Schalles

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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 – PowerPoint PPT presentation

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Title: Biology Mrs. Schalles


1
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
2
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 lifes Genetic Code
    Classification
  • B. Interdependence Environment Ecology
  • C. Evolution Darwin, Natural Selection,
    Adaptations
  • III. Scientific Method
  • Tools Techniques
  • Microscopes Other tools

3
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
4
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.
  • Well look at some of the many fields of biology.

5
Branches of Biology
  • 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

6
  • 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

7
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)

8
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

9
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.
  • Unicellular (single celled organism)
  • Multicellular (many celled organism)

-A cell is the smallest unit that can perform all
lifes processes.
10
Prokaryotic Eukaryotic cells
11
Organization -is the high degree of order within
an organisms 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
12
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)

13
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.

14
  • Atom-Molecule-Organelle-Cell-Tissue-Organ-Organism

health.yahoo.com
health.yahoo.com
web.jjay.cuny.edu
www.search.com
www.scienceaid.co.uk
www.answers.com
www.mie.utoronto.ca
Health.yahoo.com
http//orchard.sbschools.net/library/links/body.jp
g
15
2. Response to Stimuli
7 Characteristics of Living Things
  • Stimulus-
  • a physical or chemical change in the internal or
    external environment.
  • that elicits or accelerates a physiological or
    psychological activity or response.
  • 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.

ebiomedia.com
www.birds.cornell.edu
16
3. Homeostasis
B. 7 Characteristics of Living Things
  • --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 range- usually
    different than outside environment.

17
Homeostasis Questions
  • What would happen if
  • -an amoeba could not maintain a
  • different internal amount of water
  • than its 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.

18
Quick Lab- page 8Observing Homeostasis in
Goldfish
  • Read through the lab explanation.
  • I will select the lab groups.
  • Do not abuse the fish.
  • 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.

fish.dnr.cornell.edu
19
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.

20
4. Metabolism
B. 7 Characteristics of Living Things
  • is the sum of all the chemical reactions that
    take in and transform energy and materials from
    the environment.

21
5. Growth and Development
B. 7 Characteristics of Living Things
  • Growth of living things results from the division
    enlargement of cells.
  • Development is the process by which an organism
    becomes a mature adult.

22
6. Reproduction
B. 7 Characteristics of Living Things
  • life must have ability to reproduce, no organism
    lives forever.
  • Living organisms pass on hereditary information
    from parents to offspring.

23
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- dont 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

24
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
25
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.

26
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

27
7. Change over Time (Evolution)
B. 7 Characteristics of Living Things
  • Populations of living organisms evolve or change
    through time.
  • -Evolution- from evolve meaning to
  • change.

28
II. 3 Themes in Biology
  • Unity of lifes Diversity
  • -Life is diverse yet shares unity in molecules
    -DNA genetic code
  • Interdependence of Organisms
  • -organisms interact with biotic abiotic factors
  • C. Evolution - theory that organisms change over
    time, the driving force is the environment.

29
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 sugar-phosphate
    backbone.

30
Unity of Lifes Diversity
  • Taxonomy the classification of organisms
  • Tree of Life shows that all living things have
    descended with modification from a single common
    ancestor

31
Phylogenic Tree
  • Shows relationships
  • between 3 Domains 6 Kingdoms

32
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

33
3 Domains
  • Archaea -Prokaryotic cells (unicellular)
  • -little understood, recently discovered life
  • -probably oldest cells found in extreme
    environments
  • KINGDOM Archaea
  • Bacteria Prokaryotic cells (unicellular)
  • -all the common bacteria, both good bad
  • -KINGDOMBacteria
  • 3. Eukarya Eukaryotic cells (have a nucleus)
  • There are four kingdoms in Eukarya
  • Protista Fungi
  • Plantae Animalia

34
6 Kingdoms- examples
  • Archaea, Bacteria, Protista,
  • Fungi, Plantae, Animalia.

www.ucmp.berkeley.edu
www.dph.state.ct.us
www.microscopy-uk.org.uk
www.wetwebmedia.com
usuarios.lycos.es
usmo4.discoverlife.org
danny.oz.au
35
B. Interdependence
II. 3 Themes in Biology
  • Ecology- How organisms interact with both other
    organisms the environment.
  • Biotic Factors living organisms
  • Abiotic Factors - non-living part of the
    environment (water, temperature, soil type,etc)
  • Ecosystems- Communities of different living
    species (Biotic factors) interact with each
    other their non-living environment (Abiotic
    factors).

36
Ecology
  • Is the study of how
  • organisms interact
  • with each other and
  • their physical environment.
  • Environment everything- biotic abiotic-
    surrounding an organism

37
In ecology we will study
  • 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

38
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

39
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?
40
Note numbers of organisms
Chart many times more producers than large
carnivores
41
BIOSPHERE
  • the thin layer of Earths 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

42
Earth Age About 4.5 Billion Years OldLocation
In the Solar System, on the outer edge of the
Milky Way, about 28,000 light years from the
galactic center
Are we alone?
43
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.

44

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!

45
Atmosphere
  • Air Composition
  • 78 nitrogen,
  • 21 oxygen,
  • 1 other
  • Atmosphere
  • Layers
  • Trophosphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere

46
Lithosphere-
Earth Layers Inner core- solid Outer core-
liquid Mantle- solid Asthenosphere- molten
like playdough Lithosphere- solid
  • Includes the crust, is very thin
  • Fragmented into tectonic plates which move.
  • Plate movement is called plate tectonics.

47
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48
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.

49
Levels of Organization
50
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

51
Environmental Concerns-what are causes of
pollution where does it end up?
52
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.

53
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.

54
Mississippi Watershed
55
Pollution that is added to water upstream will
end up thousands of miles away.
  • 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

56
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.
57
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

58
Pennsylvania Fishes
  • Note natural environments/ oxygen needs for local
    fish
  • http//sites.state.pa.us/PA_Exec/Fish_Boat/pafish/
    fishhtms/chapindx.htm

59
Municipal Solid Waste An average person may
produce a ton of refuse in a year
  • a volume that rapidly overflows local dumps.

60
A Modern Landfill
61
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.

62
C. Evolution
(3rd Theme in Biology)
  • Theory that organisms change over time, the
    driving force is the environment.
  • Natural Selection- process by which adaptation is
    passed on to the next generation for best
    survival.
  • Adaptations-
  • -are favorable traits
  • -Ex.- cactus plants
  • adapted to desert

63
Science Religion- in answer to your questions
  • Occasionally, the media may report on the
    conflict between religion science- implying
    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.

64
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_D
arwin.jpg
65
Darwins 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.
66
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
67
Summary 4 Main Parts of Darwins 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.

68
Natural Selection
Chapter 15
4 Main Parts of Darwins Reasoning
69
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

70
Terms about Structure Function
Biology Terms Extra Info that you will need to
know
  • 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 beaks-
  • shape shows how
  • it gets food

71
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 Technology- making 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-

72
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!)
73
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.

74
Gene Therapy
  • Example replace or repair faulty gene for cystic
    fibrosis.
  • Insert a copy of good gene from healthy person
    into virus.
  • Infect patients 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.
75
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
76
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 strawberrys
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
77
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 (ß-carotene), is inserted into rice
genome.
www.goldenrice.org/
78
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
79
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

80
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 scientists goal should
    be finding facts, not support of government
    agency agenda or the desired results of a
    pharmaceutical company.

81
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.

82
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

83
Compound microscopes
Used to magnify thin slices of specimens
www.slic2.wsu.edu
84
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

85
Microscope Use
  • Carry the microscope with 2 hands-
  • By 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

86
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.

87
Magnification Resolution
  • Magnification is the increase of an objects
    apparent size.
  • Resolution is the power to show details clearly
    in an image.

88
Figure 1. Relative Size of Microbes. E.M. refers
to the Electron Microscope.
www.slic2.wsu.edu
89
Object Size and Magnifying Power of Microscopes
90
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
91
Electron Microscopes
  • Scanning electron microscopes pass a beam of
    electrons over the specimens 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.

92
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 dUnités or SI.

93
Questions
  • Which of the following is the hereditary material
    in most living things?
  • F. DNA
  • G. lipids
  • H. oxygen
  • J. carbon dioxide

94
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

95
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

96
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 objects apparent
    size
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