 Biology the Science of Life Full text notes
 Cells: 2.1.1. 2.1.2, 2.3.4,2.1.8-2.1.10
 Classification: 5.5.1, 5.5.2, 5.5.5
 Text: Ch. 1 (3-13), Ch. 23 (468-472)
 Syllabus statements
 2.1.1 – Outline the cell theory
 2.2.2 – Discuss the evidence for cell theory
 2.3.4 – Compare prokaryotic and eukaryotic cells
 2.1.8 – Explain that cells in multicellular organisms differentiate to carry out specialized
functions by expressing some of their genes but not others
 2.1.9 – State that stem cells retain the capacity to divide and have the ability to differentiate
along different pathways
 2.1.10 – Outline one therapeutic use of stem cells
 Syllabus statements
 5.5.1 –Outline the binomial system of nomenclature
 5.5.2 – List the seven levels in the hierarchy of taxa – kingdom, phylum, class, order, family,
genus, species – using an example from two different kingdoms for each level
 5.5.5 – Apply and/or design a key for a group of up to eight organisms
 Study of Life
 What is alive?
•
6 shared characteristics
•
Order, Response, Growth and Development, Use of Energy, Homeostasis, Adaptation
 How do we organize living things?
•
Hierarchy of Life
 Hierarchy of Life
 Atoms, molecules, cellular organelles, cells, tissues, organs, organ systems, organism
 The 6 characteristics of life
1. Order
All living things made of one or more cells
Cells are the basic unit of life
2. Response
Exhibit sensitivity
Response to stimuli = pupil dilation, plants grow to light, blink
3. Growth Development & Reproduction
DNA common hereditary molecule
4. Energy Utilization
Uptake and Transformation
Photosynthesis and Respiration (Green Plants & All organisms)
5. Homeostasis
Maintaining constant internal conditions (Temp, Water balance, O2/CO2 )
Behaviorally or Biologically
6. Adaptation
Change in response to Environmental Conditions
Desert organsims minimize water loss
 Energy
 Photosynthesis (Green Plants)
sunlight +water + carbon dioxide  oxygen + sugars
 Respiration (All living things)
oxygen + sugars  ATP +water + carbon dioxide
 ATP is molecular energy storage
 Cells are the basic unit of Life!!
 Cells 0-100 millionths of a meter (10-100 micrometers mm)
 Not observed until we had technology to do so
 Microscopes invented in mid 17th century
 First light microscopes then electron microscopes more recently
 Timeline of Cell Discovery
 1590 – Zachariah Jansen
-Invented compound (2 lens) microscopes
 Timeline of Cell Discovery
 1665 – Robert Hooke
-Examined cork
-First to see dead cells, called cellulae (small rooms) for little compartments
 Timeline of Cell Discovery
 1650-1700 – Anton von Leewoenhoek
-Dutch botanist used lens x200, x300
-First to examine living cells, pond water, sperm, blood
-Called animalcules (little animals) in p.w.
-single celled organisms
 Timeline of Cell Discovery
 1707-1778
Carolus Linnaeus
-swedish physician and botanist
-founder of taxonomy
-developed classification system for all living organisms
 Timeline of Cell Discovery
 1838 – Matthias Schleiden
-German botanist
-cell theory
-plant observations
*all plants made of cells
 Timeline of Cell Discovery
 1839 – Theodor Schwann
-German biologist
-Cell Theory
-All animals are made of cells
 History continued
1840
Purkinje: fibers that transmit stimulus to myocardial cells of ventricles of heart bear his
name; coined term “protoplasm” for the living content of cells.
1855: Rudolf Virchow: studied pathogenic organisms and showed that “omnis cellula e cellula” – all cells
arise from preexisting cells (by cell division).
 Timeline of Cell Discovery
 1940’s – Advent of the Electron Microscope
TEM – transmission of electrons through specimen
SEM – scanning of surface with electron
 Electron Micrographs
 Cell Theory
 Three principles based on different studies
1. All organisms made of cells
2. Cells are the basic unit of life
3. Cells come from other preexisting cells
 BUT… All cells aren’t created equal
 The two major types of cells
 Prokaryotes
(All are Prokaryotae)
1. Very small (1-10um)
2. No nucleus (nucleoid – DNA in central area)
3. No membrane bound organelles
4. Have cell walls
 Eukaryotes
(all other kingdoms)
Size 10-100 um
1. DNA in chromosomes in nucleus
2. Many M.B.O.
3. Plants & some fungi have cell walls
 To have different cells do different things you need differentiation
 So cells develop along different pathways or differentiate
 This means different cells express different genes
 Remember that every cell in an organism has all the same DNA, only some cells express
different genes within that genome
 Once the developmental pathway of a cell is started then it is usually fixed
 So which cells can differentiate?
 Stem cells – can self renew and differentiate
 Human embryos are almost all stem cells
 Some still found in different human tissues like skin, liver bone marrow
 Those only used for limited repair
 Therapeutic use of stem cells
 Area of rapid development – many uses exist
 Cord blood from umbilical cord contains hematopoietic stem cells – can become any blood cell
type
 Test the blood and remaining fluid
 Used to treat some leukemias – chemo to kill the cells that over produce white blood cells then
introduce cord blood to blood stream of patient
 Stem cells establish themselves in the marrow and replace defective cells
 Possible fates of cord blood stem cells
 Classifying all this life
 Diversity of Cells Diversity of Life
 Currently 1.5x106 identified species
 Study and grouping of this diversity is the science of taxonomy
 Taxonomic hierarchy – KPCOFGS
 Many systems – Ours 5 kingdoms
-know examples of each
 5 kingdom system: Prokaryotae
 Monera (bacteria)
 Hetero & Autotrophs
A. Archaebacteria
-primitive, extremophiles (halo-, thermo-), don’t need O2
B. Eubacteria
-most of the bacteria
-some parasites but all modes of nutrition
 5 kingdom system: Protoctista
 Protists
-eukaryotes most unicellular
-hetero & autotrophs
-algae, amoeba, ciliates, diatoms
 5 kingdom system: Fungi
 Eukaryotes – most multicellular
 Yeast, mushrooms, molds
 Heterotrohpic – acquire food by absorbtion
 If cell wall is present, made of chitin
 5 kingdom system: Plantae
 Multicellular, Autotrophic (Photosynthesis), Eukaryotes
 Cells have a cell wall made of cellulose
 Mosses, ferns, conifers, flowering plants
 5 kingdom system: Animalia
 Multicellular, Heterotrophic, Eukaryotes
 Lack cell wall
 From Largest grouping to Smallest
 Species – A population of organisms who have the potential to interbreed and produce fertile,
viable offspring
 Largest grouping of a population which can exchange genetic material but genetically isolated
from other groups
 Classifying Organisms
 Systematics – a classification process for studying biodiversity
 Taxonomy – branch of biology concerned with naming and classifying organisms
 Group species into larger categories from genus up to kingdom
 The Importance of Classification
 Common names useless – panther, puma, mountian lion, cougar = Felis concolor
 Shows evolutionary relationships – bears, raccoons sloths (p 47)
 Enables predictions of characteristics shared by members of group – e.g. new primate
discovered expect diagnostic char.
 The Importance of Classification II
 ID of organisms by organizing ecological, anatomical, physiological, molecular (DNA & protein
specifically) data
1. Proteins: Cytochrome C; has 104 Amino acids found in mitochondria
2. Consider differences in amino acids – human vs chimps = 0, human vs. dogs = 13, vs.
snakes = 20, vs tuna = 33
 Binomial Nomenclature System
 Created by C. Linneaus
 Each species has 2 part Latin name
 Genus species (computer)
 Genus species (handwritten)
 E.g.
Homo sapiens = humans
Felis sylvestris = house cat
Ranunculus acris = buttercup
 Remember: KPCOFGS
(memorize the following examples)
 Remember: KPCOFGS
(memorize the following examples)
 Review Points
 6 characteristics of Life
 Levels of the hierarchy of Life
 3 principles of Cell theory
 Difference between prokaryotes and eukaryotes
 5 kingdoms and their characteristics
 Kingdom, Phylum, Class, Order, Family, Genus, species