MAIN TOPICS OUTLINE
1.1 ORGANIZATION OF LIVING THINGS
1.11 Levels of Biological Organization.
1.2 CHARACTERISTICS OF LIVING THINGS
i. Characteristics of ALL living things.
ii. Characteristics of ORGANISMS.
iii. Characteristics of POPULATIONS.
1.3 BIOLOGICAL CHANGE OF LIVING THINGS
1.4 CLASSIFICATION OF LIVING THINGS
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LECTURE OBJECTIVES:
Many items in this chapter will be covered in General Bioology II. For General Biology I the lecture objectives are:
Explain how life is organized and list the various structural levels of biological organization.
List and differentiate between the various characteristics found in living things.
Understand that evolution is the core theme in biology (the "unifying thread" of all biological concepts).
Explain how living things are classified.
Define selected key terms.
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Key Terms
def. Adaptations: Organisms’ modification in structure, function, or behavior suitable to the environment.
def. Allele Frequency: The relative abundance of each kind of allele, carried by the individuals, in a population.
def. Atom: The smallest particle (unit) of an element that displays the characteristics of the element.
def. Biology: The science of life.
def. Biological levels of organization: Organization of life on a hierarchy of structural levels, from subatomic particles to the biosphere, each level building on the levels below, with additional properties emerging at each successive level, and life emerging at the level of cells.
def. Biosphere: Portion of Earth inhabited by life; all of the earth's waters, crust, and atmosphere in which organisms live.
def. Cell: The smallest living unit -- basic structural unit that makes up all living things.
def. Classification: Grouping and naming of objects into logical categories owing to their joint possession of attributes.
def. Control processes: Mechanisms that ensure that an organism will carry out all metabolic activities in the proper sequence (coordination) and at the proper rate (regulation).
def. Ecosystem: an interacting collection of organisms (the biotic factors) and the abiotic factors that affect them.
def. Emergent properties: Novel properties of life that emerge at higher levels in the hierarchy of biological order, not present at the simpler levels of organization.
def. Evolution: Chemical, biological, and/or cultural change over time.
def. Chemical Evolution: Progressive change (increase) in the complexity of chemicals on Earth that eventually led to the first cell.
def. Biological Evolution: Progressive change in allele frequencies over time due to genetic adaptation of a population to its environment, and the idea that all organisms descended from common ancestors ("descent of modification"). (Change within a line of descent over time.)
def. Cultural Evolution: Progressive change in the behavior of the human population, by learning behavior developed by members of previous generations.
def. Generative processes: Actions that increase the size of an individual organism (growth), or increase the number of individuals (reproduction).
def. Hierarchy: an arrangement in which larger groups include smaller groups, which include still smaller groups.
def. Kingdom: The broadest classification category of everything living on this planet.
def. Metabolic processes: The total of all chemical reactions by which each cell in an organism acquires and uses energy (=metabolism).
def. Natural selection: A mechanism of evolution, a micro-evolutionary process that encourages the passage of beneficial genes to future generations, and discourages harmful or less valuable genes -- the natural factors of the environment tend to eliminate those members of the population that are least well adapted to cope (and thus 'select' those best adapted for survival and reproduction).
def. Organism: An independent living unit.
def. Population: A group of organisms of the same species located in the same place at the same time.
def. Responsive processes: Those abilities to react to external and internal changes in the environment.
def. Species: A group of organisms (population) that can interbreed under natural conditions to produce fertile offspring that are reproductively isolated from other organisms (valid for sexually reproducing organisms only).
def. Subatomic particle: The constituents of an atom (electron, proton, and neutron).
def. Taxa: The logical categories used in naming and classifying organisms in the classification hierarchy (sing. Taxon)
def. Taxonomy: Science that identifies and classifies (naming and grouping) organisms into logical categories.
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1.1 ORGANIZATION OF LIVING THINGS
1.11 Levels of Biological Organization
• Biology is the science of life. Life is hard to define, but can be described with a list of characteristics.
The first characteristics is ORDER.
• Living things have a hierarchical organization from subatomic particles to the biosphere
Life begin at the cell level. Levels below the cell are non-living. Cells in multicellular organisms form tissues, which make up organs, which work together in organ systems, and all organ systems are joined within an organism.
There are levels of biological organization that extend beyond the individual organism. These levels are called ecological levels (populations, communities, ecosystems, the biosphere).
Each hierarchical level of biological organization is more complex than the level preceding it and has emergent properties, emergent properties, beyond those of the former level: "The whole is more than the sum of its parts", e.g., Leaves are the organs of plants. If you slice a leaf it will no longer be able to perform the functions of a leaf. The leaf has properties beyond those of the former levels.
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1 Subatomic particle SUB-CELLULAR LEVEL
2 Atom
3 Molecule
4 Macro-molecule
5 Organelle
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6 Cell (UNITS OF LIFE -- the smallest living unit) CELLULAR LEVEL
7 Tissue
8 Organ
9 Organ system
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10 Organism ORGANISMAL LEVEL
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11 Population ECOLOGICAL LEVEL
12 Community
13 Ecosystem
14 Landscape
15 Biosphere
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1.2 CHARACTERISTICS OF LIVING THINGS
• The cell is the basic structure and functional unit of life.
The CELL is the smallest unit which has all the characteristics of living things. The cell is the smallest unit of organization having a capacity to survive and reproduce on its own.
• Life is hard to define.
Life characteristics are in the table below. 
The first level of characteristics is ORDER (as discussed above in 1.1). Living things have a complex organization, and can take in and use energy, grow and develop, reproduce, and show variation based on heredity.
The table is separated into three subunits:
all living things
individual organisms
populations (many individual organisms of the same species).
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Life Characteristics.
Characteristics of ALL LIVING THINGS (& some non-living objects):
– order (levels of biological organization)
-- living things organized in units:
- CELLS (units of life)
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Characteristics of ORGANISMS (most lacking in non-living objects):
• METABOLIC PROCESSES -- chemical reactions within an organism
– nutrient uptake
– nutrient processing
– waste elimination
• GENERATIVE PROCESSES -- increase the size & #'s of organism
– growth
– reproduction
• RESPONSIVE PROCESSES -- react to external and internal changes
– irritability
– individual adaptation
• CONTROL PROCESSES -- so all metabolic activities function properly
– coordination proper sequence
– regulation proper rate
Characteristics of POPULATIONS (lacking in individual organisms):
• RESPONSIVE PROCESSES -- react to external and internal changes
– population adaptation (see biological change of living things )
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1.3 BIOLOGICAL CHANGE OF LIVING THINGS
EVOLUTION
• Populations can adapt to changes in the environment
The mechanism of evolution is usually NATURAL SELECTION.
Adaptations to the environment are modifications that make organisms suited to their way of life. If these adaptations are genetically controlled they can be passed on to future generations. Nature can then "select" the adaptation which is best suited -- this is Natural Selection.
Natural selection acting on genetic adaptation changes within a population. This gene frequency changes may cause populations to evolve. POPULATIONS evolve NOT individuals!
We know that Earth has changed over millions of years, e.g., there used to be gigantic reptiles called dinosaurs. They are now extinct.
Natural selection acted on genetic adaptation changes within the dinosaur population. Their adaptations to the environment allowed them to survive for over 250 million years... then something happened that made them go extinct.
(Evolution will be discussed later in General Biology I.)
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1.4 CLASSIFICATION OF LIVING THINGS
TAXONOMY
• Classification is to group and to name organisms after evolutionary relationships. Scientists who classify (give names to) organisms and place them in groups are called taxonomists.
Linné (Linnaeus): (Father of modern taxonomy) Swedish medical doctor and botanist mid 1700th.
In 1758 published Systema Naturae
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1.41 Domains & Kingdoms
• Biologists classify organisms into major groups (taxa) called kingdoms.
During the times of Linné two (2) kingdoms were recognized:
• Animalia (including animallike microorganisms)
• Plantae (including fungi, plantlike microorganissms, and bacteria)
For a long time a five (5) kingdom system of classification has been recognized:
• Animalia
• Plantae
• Fungi
• Protista
• Monera (= bacteria)
Today many biologists recognize six (6) kingdoms. The Monera divided into two kingdoms: Archaebacteria and Eubacteria. (Scientists may eventually recognize additional kingdoms.)
• Animalia
• Plantae
• Fungi
• Protista
• Archaebacteria (= bacteria)
• Eubacteria (= bacteria)
In addition these 6 kingdoms are placed in three (3) "domains". A domain is a "new" taxonomic category above the kingdom. The two bacterial kingdoms form their own two domains (Archaea and Bacteria), and the other four non-bacterial kingdoms form the domain Eukarya. Based on cell type the two bacteria groups belong to the same group, having a prokaryotic cell type, while eukarya has a eukaryotic cell type. (Cell types will be discussed later in General Biology I.)
• Eukarya
• Archaea
• Bacteria
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• Scientists name and classify organisms giving all living organisms a two-part name, binomial name, in Latin.
-- Humans are classified in the Kingdom: Animalia
-- We are a species named: Homo sapiens
Homo -- genus name, capital H
sapiens -- specific epithet, small s and also end with another s,
and the binomial Homo sapiens -- the scientific species name of "man".
Copyright 2002, 2003, 2004, 2005, Jan A. Nilsson. Web page layout and design © and intellectual property Jan A. Nilsson. All rights reserved. Reproduction of the whole or any part of the contents without written permission is prohibited. Page created 10.XII.2002, last updated 16.VII.2005, most likely during the wee hours of the morning on a G3 PowerBook owned by Jan A. Nilsson.
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