01-chapt01 lecture - nassau community college [compatibility...injury, acquiring food or ... from...

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Chapter 01

Lecture Outline

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without

notes.

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planet Earth

mushroom on northern

forest floor

male peacock

displaying feathershumans in a city

giant sequoia

Masai giraffes

monarch butterfly

feeding on nectar

(sequoia): © Robert Glusic/Getty RF; (mushroom): © IT Stock/Age Fotostock RF; (peacock): © Brand X Pictures/PunchStock RF; (humans): © Heath

Korvola/UpperCut Images/Getty RF; (giraffes): © Dr. Sylvia S. Mader; (butterfly): © Creatas/PunchStock RF; (Earth): © Ingram Publishing/Alamy RF

Figure 1.1

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1.1 The Characteristics of Life

• Life exists almost everywhere on Earth.

• Earth possesses a great variety of diverse life forms.

• All living things have certain characteristics

in common.

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The Characteristics of Living

Organisms

• Are organized

• Acquire materials and energy

• Reproduce

• Respond to stimuli

• Are homeostatic

• Grow and develop

• Have the capacity to adapt

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Organisms organized

in a hierarchy of levels

• A cell is the smallest unit of life.

• A tissue is a group of

similar cells that perform a particular function.

• Several tissues join

together to form an organ.

• Organs work together to form an organ system.


nerve cellplant cell

nerve tissue

tree

Organisms

Organ Systems

organ system

Organs

Tissues

Cells

human

leaf tissues

Atoms

Molecules

leaf brain

DNA molecule

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• Organisms need external material and

energy sources to maintain their organization and carry on life’s activities.

• Energy is the capacity to do work.

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Organisms Reproduce

• Life arises from life.

• Genes are units of information within an

individual’s DNA.

• Reproduction is the process by which an organism makes more of itself.

• DNA which directs cellular functions is duplicated prior to an organism

reproducing.

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Organisms Respond to Stimuli

• Organisms respond to external stimuli by

moving toward or away from the stimuli.

• Organisms use a variety of mechanisms

for movement in response to stimuli.

• Movement of an organism constitutes a

large part of its behavior.

• Behavior is directed toward avoiding

injury, acquiring food or mating.

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Organisms are Homeostatic

• Homeostasis (“staying the same”) refers

to the requirement that organisms maintain a relatively constant internal environment.

• For example, human body temperature

fluctuates slightly throughout the day.

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• Growth – increase in size or number of cells

• Development – changes that take place

from conception to death

Figure 1.4

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Organisms Have the Capacity

to Adapt• During the nearly 4 billion years that life

has been on Earth, the environment has constantly changed.

• Some individuals of a species may be better fit in a new environment.

• Adaptations are features that make

individual organisms better suited to the new environment.

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Organisms Have the Capacity

to Adapt• Individuals better adapted to their

environment tend to produce more offspring.

• Natural Selection is the differential

reproductive success of adapted individual.

– Results in changes of characteristics of a

population over time

• Evolution the change in frequency of traits in populations and species.

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1.2 The Classification of

Organisms• Living organisms are assigned to groups

based upon their similarities.

• Systematics is the discipline of identifying

and classifying organisms.

• Each organism is classified in a domain,

kingdom, phylum, class, order, family, genus and species.

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Domains

• Domains are the largest classification

category.

• Organisms are assigned to 1 of 3 domains

based on biochemical and genetic evidence:

domain Archea, domain Bacteria, or domain Eukarya.

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Domains

• Domains Archea and Bacteria include

unicellular prokaryotic cells.

– Cells that lack a true nucleus

• Domain Eukarya include eukaryotic cells.

– Cells with a true nucleus

– Genes found in the DNA within the nucleus

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Domain Archaea

• Archaea live in extreme

environments.

– Too little O2, too salty, too hot, or too acidic for most other organisms

Figure 1.5a


DOMAIN ARCHAEA

Methanosarcina mazei

a. Archaea are capable of living in extreme environments.1.6 µm

© Ralph Robinson/Visuals Unlimited

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Domain Bacteria

• Bacteria are found almost everywhere on

the planet Earth.

• Some are present within humans.

• Some bacteria cause

disease but many are beneficial.

Figure 1.5b

DOMAIN BACTERIA

b. Bacteria are found nearly everywhere.

Escherichia coli

1.5 µm


© A.B. Dowsett/SPL/Photo Researchers, Inc.

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Kingdoms

• Eukaryotes (Domain Eukarya) are further categorized into one of four Kingdoms

– Kingdom Protista – may be several kingdoms

– Kingdom Fungi

– Kingdom Plantae

– Kingdom Animalia

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Representative Organisms

black bread mold yeast mushroom bracket fungus

sea star earthworm finch raccoon

moss fern pine tree

paramecium euglenoid slime mold dinoflagellate

Kingdom Organization Type of Nutrition

Protista

Fungi

Plantae

Animalia

Absorb food

Ingest food

c. Eukaryotes are divided into four kingdoms.

DOMAIN EUKARYA

Complex single cell,

some multicellular

Some unicellular,

most multicellular

filamentous formswith specialized

complex cells

Multicellular form

with specialized

complex cells

Multicellular form

with specialized

complex cells

Absorb,

photosynthesize,

or ingest food

Photosynthesize

food

nonwoody

flowering plant

Protozoans,

algae, water molds,

and slime molds

Molds, yeasts,

and mushrooms

Mosses, ferns,

nonwoody and

woody floweringplants

Invertebrates,

fishes, reptiles,

amphibians, birds,and mammals


Figure 1.5c

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Representative Organisms

black bread mold yeast mushroom bracket fungus

sea star earthworm finch raccoon

moss fern pine tree

paramecium euglenoid slime mold dinoflagellate

Kingdom Organization Type of Nutrition

Protista

Fungi

Plantae

Animalia

Absorb food

Ingest food

Methanosarcina mazei

1.6 µµµµm 1.5 µµµµm

DOMAIN BACTERIA

Escherichia coli

a. Archaea are capable of living in extreme environments. b. Bacteria are found nearly everywhere.

c. Eukaryotes are divided into four kingdoms.

DOMAIN ARCHAEA

DOMAIN EUKARYA

Complex single cell,

some multicellular

Some unicellular,

most multicellular

filamentous formswith specialized

complex cells

Multicellular form

with specialized

complex cells

Multicellular form

with specialized

complex cells

Absorb,

photosynthesize,

or ingest food

Photosynthesize

food

nonwoody

flowering plant

Protozoans,

algae, water molds,

and slime molds

Molds, yeasts,

and mushrooms

Mosses, ferns,

nonwoody and

woody floweringplants

Invertebrates,

fishes, reptiles,

amphibians, birds,and mammals

(bacteria): © A.B. Dowsett/SPL/Photo Researchers, Inc.; (archaean): © Ralph Robinson/Visuals Unlimited

Figure 1.5

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Categories of Classification

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species Least inclusive

Most inclusive

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• Systematics helps biologists better

understand the variety of life on Earth.

• Organisms are classified according to their

presumed evolutionary relationships.

• Systematists now perform experiments

that may result in changes in the current

classification system.

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Scientific Names

• Taxonomy is the assignment of a

binomial to each species.

• Binomial (two name)

– Genus name, species name

– Genus capitalized, both words in italics

–Examples:

»Homo sapiens

»Pisum sativum

»Felis domesticus

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1.3 The Organization of the

Biosphere

• Biosphere– The zone of air, land, and water at the surface

of the Earth where living organisms are found

• Population

– All the members of a species within a particular area

• Community

– All the different populations in the same area

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The Organization of the

Biosphere• Ecosystem

– Community interact among themselves & with the physical environment (soil, atmosphere,

etc.)

– Characteristics

• Chemical cycling – chemicals move from one species to another

• Energy flow – energy flows from the sun, through plants, through the food chain

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heat


Chemical cycling

heat

heat

heat

heat

heat

Energy flow

WASTE MATERIAL,DEATH,AND DECOMPOSITION

solarenergy

Figure 1.6

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Ecosystems

• Climate largely determines where different ecosystems are found around the globe.

• The two most biologically diverse ecosystems—

tropical rain forests and coral reefs—occur where solar energy is most abundant.

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detritus

phytoplankton

corals

sponges

white shark

bar jack

queen angelfish

parrotfish

surgeonfish

sea grass

great

barracuda

attached

algae

green

moray

yellowtail

snapper

Spanish

hogfish

yellow

jack

sea

star

Bermuda

chub

yellowtail

damselfish

foureye

butterfly fish

sea

urchin

zooplankton

spiny

lobster

Figure 1.7

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The Human Species

• The human species tends to modify existing

ecosystems for its own purposes.

• Tropical rain forests and coral reefs are

severely threatened as global human population increases.

• Humans depend on healthy ecosystems for

food, medicine, and raw materials.

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Biodiversity

• Encompasses

– Total number of species

– The variability in their genes

– The ecosystems in which they live

• As many as 5-30 million species exist on

Earth.

• Human activities cause the extinction of

about 400 species per day.

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1.4 The Process of Science

• Biology is the scientific study of life.

• Biologists—and all scientists—generally

test hypotheses using the scientific method.

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Observation

Hypothesis

Experiment/Observations

New observationsare made, and previous

data are studied.

Input from various sourcesis used to formulate a

testable statement.

The hypothesis istested by experiment

or further observations.

Many experiments andobservations support a

theory.

Scientific Theory

Conclusion

The results are analyzed,and the hypothesis issupported or rejected.

© Photo by Ron Nichols, USDA Natural Resources Conservation Service

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Observation

• Scientists tend to be curious about nature

and how the world works.

• Natural phenomena may be better

understood by observing and studying them.

• Scientist use their senses to make

observations.

• They can extend their abilities by using

instruments.

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Hypothesis

• Inductive reasoning occurs when one

uses creative thinking to combine isolated facts into a cohesive whole.

– A scientist states a hypothesis, a tentative

explanation for the natural event.

– It is presented as a falsifiable statement.

– Personal experiences may influence their hypothesis.

– Hypotheses should be testable.

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Experiment/Further Observations

• To determine how to test a hypothesis,

scientists use deductive reasoning

– Involves “if, then” logic

• For example, a scientist might reason, if

organisms are composed of cells, then

examination of an organism should reveal cells.

• One can also imply that the scientist has made a prediction.

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Experiment/Further

Observations• To test their hypothesis, scientists conduct

experiments.

• Experimental design is the manner in

which a scientist intends to conduct an experiment.

• Experimenter should ensure that testing is

specific and the results will be meaningful.

• A control should be included in the

experiment.

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Experiment/Further

Observations

• Scientists often use a model, a representation of an actual subject.

• For example:

– Computer modeling to study climate changes

– Mice to perform cancer research

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Data

• Data represent the results of an experiment.

– Should be observable and objective

– Should not be subjective or opinion-based

• Mathematical data is displayed as table and/or graph.

• Statistical data is used to rule out that results were due to chance.

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Conclusion

• A conclusion is the analysis of the data to

determine if the hypothesis can be supported or not.

• The conclusion from one experiment may be used to form a hypothesis for another

experiment.

• If the results do not support the hypothesis, then it may be used to formulate an

alternate hypothesis.

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Scientific Theory

• Scientific theories are concepts that join

together well-supported and related hypotheses.

• In science, a theory is supported by a broad range of observations, experiments, and

data.

– Examples: cell , homeostasis, gene, ecosystem, and evolution

• The theory of evolution is the unifying

concept of biology.

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A Controlled Study

• Experiments in controlled studies have two

types of groups:

• Control Group – receives no treatment

• Experimental Group – receives treatment


Factor of the experiment

being tested

Response Variable

(Dependent Variable)

Result or change that occurs

due to the experimental variable

Experimental Variable

(Independent Variable)

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A Controlled Study

• Experimental background:

– nitrogen fertilizers increase crop yields in the

short term;

– continued use can cause pollution, as well as alter soil properties;

– altered soil properties lead to reduced crop

yields;

– one solution is to leave the land unplanted for several years.

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A Controlled Study

• Experimental background:

– An alternate to nitrogen fertilizers is to use legumes, such as peas or beans.

– These plants allow the growth of bacteria on their root nodules.

– These bacteria convert atmospheric nitrogen to a form usable to plants.

– These legume crops can be rotated with cereal crops to increase yield.

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The Experiment

• HYPOTHESIS: A pigeon pea/winter wheat rotation will cause winter wheat production to

increase, as well as, or better than, nitrogen fertilizer.

• PREDICTION: Wheat production (biomass) following the growth of pigeon peas will surpass

wheat biomass following nitrogen fertilizer treatment.

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The Experiment

• Control Pots

– Winter wheat with no nitrogen fertilizer or legume preplanting

• Test Pots– Winter wheat in soil treated with nitrogen fertilizer

(45kg/ha)

– Winter wheat in soil treated with nitrogen fertilizer (90kg/ha)

– Pigeon pea plants tilled into soil and then winter wheat planted

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90 kg of nitrogen/ha Pigeon pea/winter wheat rotation

Control pot

no fertilization treatment

Test pot

45 kg of nitrogen/ha

a. Control pot and three

types of test pots

Test pot Test pot


Courtesy Jim Bidlack

Figure 1.10a

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The Experiment

• All other conditions were kept the same in

all pots.

– Exposed to same environmental conditions

– Watered equally

• The following spring, wheat plants were

dried and weighed.

• Biomass was determined.

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b. Results

20

10

5

0year 1 year 2 year 3

= no fertilization treatment

= 45 kg of nitrogen/ha

Control Pots


= Pigeon pea/winter wheat rotation

Wh

eat B

iom

ass (

gra

ms/p

ot)

15Test Pots

Figure 1.10b

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90 kg of nitrogen/ha Pigeon pea/winter wheat rotation

Control pot

no fertilization treatment

Test pot

45 kg of nitrogen/ha

b. Results

20

10

5

0year 1 year 2 year 3

= no fertilization treatment


Control Pots


= Pigeon pea/winter wheat rotation

Wh

ea

t B

iom

as

s (

gra

ms

/po

t)

15

a. Control pot and three

types of test pots

Test pot Test pot

Test Pots


Courtesy Jim Bidlack

Figure 1.10

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The Experiment

• The results after one year:– Wheat biomass was higher in test pots than control

pots.

– Pots with 45kg/ha of fertilizer had only slighter higher biomass.

– Pots with 90kg/ha of fertilizer had nearly twice the biomass as control.

– Pots with pigeon pea plants tilled into soil and then winter wheat planted did not have a biomass greater than control pots.

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Continuing The Experiment

• The Results after Two Years:

– Conclusion: The hypothesis was supported.

– At the end of two years, the yield of winter

wheat following a pigeon pea/winter wheat rotation was better than for the other type pots.

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Continuing The Experiment

• The Results after Three Years:

– Winter wheat biomass decreased in both the control pots and pots treated with nitrogen

fertilizer.

– Pots with fertilizer still had more wheat biomass than control pots.

– Wheat biomass increased almost fourfold in pots pea/wheat rotation.

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Ecological Importance of Study

• The use of legumes long-term was more

effective in wheat biomass production than the use of nitrogen fertilizer.

• This study represents a form of organic gardening which not only increased yield,

but also reduced pollution.

• Organic farming may benefit farmers and the environment.

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1.5 Science and Social

Responsibility

• Technology is the application of knowledge for a practical purpose.

• Technology has both benefits and drawbacks

• Ethical and moral issues surrounding the use of technology must be decided by everyone.

– Responsibility for how to use scientific technology must reside with people from all walks of life, not with scientists alone.

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