This document provides an overview of key concepts in biology. It begins by defining life and listing 7 characteristics of living things, including responding to stimuli, maintaining internal conditions, acquiring and using energy, growth, reproduction, heredity through DNA, and evolution. It then discusses the hierarchical levels of biological organization from atoms to ecosystems. Key points include that living things are complex and organized, and cells are the basic unit of life. The document also categorizes life into the three domains of Bacteria, Archaea, and Eukarya, and discusses their prokaryotic or eukaryotic cell structure and unicellular or multicellular nature. Energy acquisition through photosynthesis or consumption is also addressed.

1. CHAPTER 1:
An Introduction to Life On Earth

2. Defining Life
• Dictionary definition of life is:
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3. Characteristics defining LIFE
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4. Living Things Are Both Complex and
Organized
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5. Living Things Are Both Complex and
Organized
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6. Living Things Are Both Organized
and Complex
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Living Things Are Both Organized
and Complex

8. Least complex
Most complex Biosphere
Ecosystem
Community
Multicellular
Organism
Organ
System
Organ
Tissue
Cell
Organelle
Molecule
Subatomic
Particle
Atom
That part of Earth inhabited
by living organisms; includes both
the living and nonliving components
A structure usually
composed of several tissue
types that form a functional unit
A community together with its
nonliving surroundings
Two or more populations of different
species living and interacting in the
same area
An individual living thing composed
of many cells
Two or more organs working
together in the execution of
a specific bodily function
A group of similar cells that perform
a specific function
The smallest unit of life
A structure within a cell that performs
a specific function
A combination of atoms
The smallest particle of an element
that retains the properties of
that element
Particles that make up an atom
carbon nitrogen oxygen
hydrogen
proton neutron electron
DNA
glucose
water
mitochondrion nucleus
chloroplast
nerve cell
nervous tissue
the brain
the nervous system
Earth's surface
snake, antelope, hawk, bushes, grass, rocks, stream
snake, antelope, hawk, bushes, grass
herd of pronghorn antelope
pronghorn antelope
Population
Members of one species inhabiting
the same area
Species
Very similar, potentially interbreeding
organisms
LEVELS
OF
BIOLOGICAL
ORGANIZATION

9. O
H H
CH2OH
Subatomic Electron
Neutron
Proton
Nitrogen
Carbon
Hydrogen Oxygen
DNA
Glucose
Water
Nucleus
Chloroplast
Mitochondrion
Nerve Cell
Atomic
Molecular
Organelle
Cellular
Least complex
Most complex
LEVELS
OF
BIOLOGICAL
ORGANIZATION

10. Tissue Nervous
Tissue
Brain
Nervous
System
Pronghorn
Antelope
Organ
Organ System
Organism
Least complex
Most complex
LEVELS
OF
BIOLOGICAL
ORGANIZATION

11. Population
Herd of Pronghorns
Hawk
Water
Earth’s
surface
Community
Ecosystem
Biosphere
Pronghorns
Hawk Grass
Pronghorns
Snake
Bushes
Soil
Air
Snake
Least complex
Most complex
LEVELS
OF
BIOLOGICAL
ORGANIZATION
This is a good exam question!

12. cell membrane
nuclear envelope
nucleus
cell wall
organelles
The CELL: Smallest unit of LIFE

13. Living Things Respond to Stimuli
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14. Living Things Maintain Internal
Conditions
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15. Living Things Acquire and Use
Materials and Energy
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16. Living Things Grow
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17. Living Things Reproduce Themselves
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18. DNA is the Molecule of Heredity
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19. DNA is the Molecule of Heredity
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20. Living Things As a Whole Have the
Capacity to Evolve
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21. Categorizing Life
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22. cell wall
plasma
membrane
genetic material
(DNA)
A color-enhanced electron micrograph of a dividing
bacterium. Bacteria are unicellular and prokaryotic;
most are surrounded by a thick cell wall. Some bacteria
photosynthesize, but most absorb food from their
surroundings.
1 micrometer
The domain Bacteria

23. A color-enhanced electron micrograph of an archaean. The
cell wall appears red, and DNA is scattered inside. Many
archaeans can survive extreme conditions. This Antarctic
species lives at temperatures as low as –2.5°C.
The domain Archaea

24. Categorizing Life
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25. This light micrograph of a Paramecium illustrates the
complexity of these large, normally single, eukaryotic
cells. Some protists photosynthesize, but others ingest
or absorb their food. Many, including Paramecium, are
mobile, moving with cilia or flagella.
10 micrometers
oral groove
(“mouth”)
contractile
vacuole
food
vacuoles
A protist (domain Eukarya)

26. The kingdom Fungi (domain Eukarya)
An exotic mushroom found in Peru. Most fungi are
multicellular. Fungi generally absorb their food, which is
usually the dead bodies or wastes of plants and animals. The
food is digested by enzymes secreted outside the fungal
body. Most fungi cannot move.

27. The kingdom Plantae (domain Eukarya)
This butterfly weed represents the flowering plants, the
dominant members of the kingdom Plantae. Flowering
plants owe much of their success to mutually beneficial
relationships with animals, such as these pearl crescent
butterflies, in which the flower provides food and the
insect carries pollen from flower to flower, fertilizing
them. Plants are multicellular, nonmotile eukaryotes that
acquire nutrients by photosynthesis.

28. The kingdom Animalia (domain Eukarya)
A wrasse rests on a soft coral. Animals are multicellular;
animal bodies consist of a wide assortment of tissues and
organs composed of specialized cell types. Most animals can
move and respond rapidly to stimuli. The coral is a member
of the largest group of animals: the invertebrates, which lack
a backbone. This group also includes insects and mollusks.
The wrasse is a vertebrate; like humans, it has a backbone.

29. Categorizing Life
• There are 3 characteristics are
particularly useful to categorize life
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31. Prokaryotic and Eukaryotic Cells
Types in the Domains
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32. Unicellularity and Multicellularity in Bacteria,
Archaea, and the Kingdoms of Eukarya
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33. Ways Organisms Acquire Energy
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34. Ways Organisms Acquire Energy
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35. Scientific Principles Underlie All
Scientific Inquiry
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36. Principle I: Natural Causality
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37. Principle II: Natural Laws Apply Everywhere
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38. Principle III: Science Assumes Similar
Perceptions Among All Humans
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39. The Scientific Method Is the Basis for
Scientific Inquiry
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40. Important Experimental Considerations
in the Scientific Method
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41. Experimental variable:
gauze prevents
entry of flies
Controlled variables:
time, temperature,
place
Results
Control situation Experimental situation
Spontaneous generation of maggots
from meat does not occur; flies are
probably the source of maggots.
Flies swarm around meat left in the open;
maggots appear on meat.
Place meat
in each jar.
Obtain identical pieces of
meat and two identical jars.
Flies swarm around
and maggots appear.
Leave jar
uncovered.
Leave exposed
for several days.
Flies kept from meat;
no maggots appear.
Cover jar
with gauze.
Leave covered
for several days.
Flies produce the maggots; keeping flies away
from meat will prevent the appearance of maggots.
Francesco Redi’s experiment
4 steps

42. Limitations of the Scientific Method
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43. Science is a Human Endeavor
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44. Fleming’s Discovery of Penicillin Highlights Real
Science in the 1920s

45. Scientific Theories Have Been
Thoroughly Tested
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46. Types of Reasoning Used in Science
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47. Three Natural Processes Underlie
Evolution
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48. Much of the Variability Among
Organisms is Inherited
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49. Much of the Variability Among
Organisms is Inherited
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50. Natural Selection Preserves Genes that
Enhance Survival and Reproduction
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51. Biodiversity Arises from Different
Environmental Challenges
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52. Biodiversity Arises from Different
Environmental Challenges
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