Transcript Slide 1

An Introduction to the
Science of Botany
Chapter 1
TTU MS 43131
LEARNING OBJECTIVES
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Briefly describe the field of botany, and give short
definitions of at least five subdisciplines of plant
biology
Summarize and discuss the features of plants and other
organisms that distinguish them from nonliving things
Distinguish among the six kingdoms and three
domains, and give representative organisms for each
Summarize the main steps in the scientific method, and
explain how science differs from many other human
endeavors
LEARNING OBJECTIVE 1
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Briefly describe the field of botany, and give
short definitions of at least five subdisciplines
of plant biology
KEY TERMS
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BOTANY The scientific study of plants; also
called plant biology
Subdisciplines 1
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Plant molecular biology
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Structures and functions of important biological
molecules (proteins, nucleic acids)
Plant cell biology
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Structures, functions, and life processes of plant
cells
Subdisciplines 2
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Plant physiology
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How plants function (photosynthesis, mineral
nutrition)
Plant genetics
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Plant heredity and variation
Subdisciplines 3
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Plant ecology
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Interrelationships among plants, and between plants
ands their environment
Overgrazing in Africa
p. 5
p. 7
LEARNING OBJECTIVE 2
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Summarize and discuss the features of plants
and other organisms that distinguish them from
nonliving things
KEY TERMS
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PHOTOSYNTHESIS
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Biological process that includes capture of light
energy and its transformation into chemical energy
of organic molecules that are manufactured from
carbon dioxide and water
CELLULAR RESPIRATION
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Cellular process in which energy of organic
molecules is released for biological work
KEY TERMS
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DEOXYRIBONUCLEIC ACID (DNA)
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A nucleic acid present in a cell’s chromosomes that
contains genetic information
KEY TERMS
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EVOLUTION
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Cumulative genetic changes in a population of
organisms from generation to generation
NATURAL SELECTION
Mechanism of evolution (Charles Darwin)
 Tendency of organisms that have favorable
adaptations to their environment to survive and
become parents of next generation
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Levels of Biological Organization
Atoms
Hydrogen
Biosphere
Oxygen
Molecule
Ecosystem
Water
Community
Chloroplast
Macromolecule
Population
Organelle
Cell
Epidermis
Organism
Tissue
Organ
Fig. 1-3, p. 9
Characteristics of Living Things 1
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Organization
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Plants and other organisms are highly organized with
cells as their basic building blocks
Energy
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Plants and other organisms take in and use energy
Plant Cells
Photosynthesis
Characteristics of Living Things 2
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Interaction with environment
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Plants respond to stimuli in their environment
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Plants undergo growth and development
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Reproduction
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Plants form new individuals by asexual or sexual
reproduction
Root Growth and Gravity
Response to Stimuli
Germination
Asexual Reproduction
Characteristics of Living Things 3
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Heredity
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DNA molecules transmit genetic information from
one generation to the next in plants and other
organisms
Evolution
Plants and other organisms evolve
 Populations change or adapt to survive in changing
environments
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Adaptation
LEARNING OBJECTIVE 3
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Distinguish among the six kingdoms and three
domains, and give representative organisms for
each
KEY TERMS
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SPECIES
A group of organisms with similar structural and
functional characteristics
 In nature, they breed only with one another and have
a close common ancestry
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KEY TERMS
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KINGDOM
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A broad taxonomic category made up of related
phyla; many biologists currently recognize six
kingdoms of living organisms
DOMAIN
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A taxonomic category that includes one or more
kingdoms
Organisms are classified into a
hierarchy
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The main categories of classification are:
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Domains,
Kingdoms,
Phyla,
Classes,
Orders,
Families,
Genera, and
Species.
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(e.g. house, street, city, county, state, country, continent, planet)
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King Phillip Came Over Fearing Green Snakes
Three-Domain Classification
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Archaea
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Bacteria
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Kingdom archaea
Kingdom bacteria
Eukarya
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All other kingdoms
Euglena
Kingdoms and Domains
Six-Kingdom Classification 1
1. Archaea
2. Bacteria
3. Protista
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protozoa, algae, water molds, slime molds
Six-Kingdom Classification 2
4. Fungi
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molds, yeasts
5. Animalia
6. Plantae
Three Domains:
Bacteria
Archaea
Eukarya
Six Kingdoms:
Bacteria
Prokaryotes (lack
membrane-bound
organelles);
unicellular;
most are
heterotrophic
(obtain food by
eating other
organisms),
but some are
photosynthetic or
chemosynthetic
Archaea
Prokaryotes;
unicellular;
microscopic;
most live in
extreme
environments;
differ in
biochemistry
and in cell wall
structure
from bacteria
Protista
Eukaryotes;
mainly
unicellular or
simple
multicellular;
maybe
heterotrophic
or photosynthetic;
include protozoa,
algae, and slime
molds
Plantae
Eukaryotes;
multicellular;
photosynthetic;
life cycle with
alternation of
generations;
cell walls of
cellulose
Animalia
Eukaryotes;
multicellular;
heterotrophic;
most move
about by
muscular
contraction;
nervous
system
coordinates
responses to
stimuli
Fungi
Eukaryotes;
most
multicellular;
heterotrophic;
absorb
nutrients;
do not photosynthesize;
cell walls of
chitin
Fig. 1-11, p. 14
Classification (Binomial System)
LEARNING OBJECTIVE 4
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Summarize the main steps in the scientific
method, and explain how science differs from
many other human endeavors
KEY TERMS
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HYPOTHESIS
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An educated guess (based on previous observations)
that may be true and is testable by observation and
experimentation
THEORY
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A widely accepted explanation supported by a large
body of observations and experiments
The Scientific Method 1
1. Recognize a problem
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or an unanswered question
2. Develop a hypothesis
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to explain the problem
3. Design and perform an experiment
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to test the hypothesis
The Scientific Method 2
4. Analyze and interpret the data
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to reach a conclusion
5. Share new knowledge
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with the scientific community
Charles Darwin’s experiment with
stems detecting light. Charles
Darwin published his results on a
number of different scientific studies
in addition to his works on evolution.
Through experimentation, he
discovered that the tip of a stem
detects light. (a) If the tip is covered,
the stem does not grow toward the
light. (b) If uncovered, the tip bends
in the direction of the light.
Forming and testing
hypotheses. The
scientific method
consists of observations
that lead to a question.
One or more
hypotheses tentatively
answer the question.
Each hypothesis is then
tested by experiments,
which either support it
or do not support it.
Based on
experimentation, the
hypothesis is either
accepted or rejected.
Conservation Biology
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Extinction as a consequence of human activities
Loss of Plant and Animal habitats