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Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

PowerPoint Lectures for Biology, Seventh Edition

Neil Campbell and Jane Reece

Lectures by Chris Romero

Chapter 1Chapter 1

Exploring Life

Figure 1.1


Biology is the study of life.• All living organisms share certain general properties

that separate them from nonliving things.Properties of Life• Cellular organization• Reproduction• Metabolism• Homeostasis• Heredity• Responsiveness• Growth and development• Interdependence


• Some properties of life

Figure 1.2

(c) Response to the environment

(a) Order

(d) Regulation

(g) Reproduction (f) Growth and development

(b) Evolutionary adaptation

(e) Energy processing


• ORDER (Cellular organization) •every living thing is composed of one or more tiny, highly organized structures with thin membrane coverings, called: cells

–the cell is the smallest unit capable of all life functions

Characteristics of Life


• The study of life extends from the microscope scale of molecules and cells to the global scale of the entire living planet

Cell

8 Cells

6 Organs and organ systems

7 Tissues

10 Molecules

9 Organelles

50 µm

10 µm

1 µm

Atoms

Figure 1.3


The hierarchy of life extends through many levels of biological organization

• From the biosphere to organisms

Figure 1.3

1 The biosphere

2. Ecosystem

3. Biome

4. Community

5. Population


• The CELL is basic unit of life

– Is the lowest level of organization that can perform all activities required for life

25 µmFigure 1.5


A Closer Look at Cells

• The first cells were observed and named by Robert Hooke in 1665 from a slice of cork.

• Anton van Leeuwenhoek first saw single-celled organisms in pond water and observed cells in blood and sperm.


A Closer Look at Cells, continued

• In 1839, Matthais Schleiden and Theodor Schwann extrapolated from their own microscopic research and that of others to propose the cell theory.

– The cell theory postulates that all living things consist of cells and that all cells come from other cells.

• New cells are produced by the division of existing cells, the critical process in reproduction, growth, and repair of multicellular organisms.



• All cells share two main characteristics

– They are all enclosed by a plasma membrane

Egg cell

Sperm cell

NucleicontainingDNA

Fertilized eggwith DNA fromboth parents

Embyro’s cells with copies of inherited DNA

Offspring with traitsinherited fromboth parentsFigure 1.6



• All cells share the molecular structure of DNA

– They all contain chromosomes made partly of DNA, the substance of genes which program the cells’ production of proteins and transmit information from parents to offspring in a process called HEREDITY

DNA

Cell

Nucleotide

ACTA

T

A

CC

G

G

TA

TA

(b) Single strand of DNA. These geometric shapes and letters are simple symbols for the nucleotides in a small section of one chain of a DNA molecule. Genetic information is encoded in specific sequences

of the four types of nucleotides (their names are abbreviated here as A, T, C, and G).

(a) DNA double helix. This model shows

each atom in a segment of DNA.Made up of two long chains of building blocks called nucleotides, a DNA molecule takes the three-dimensional form of a double helix.

Figure 1.7

Nucleus



• There are TWO main forms of cells

– EUKARYOTIC cells are subdivided by internal membranes into various membrane-bound organelles

EUKARYOTIC CELL

Membrane

Cytoplasm

Organelles

Nucleus (contains DNA) 1 µm

PROKARYOTIC CELL

DNA

(no nucleus)Membrane

Figure 1.8



• There are TWO main forms of cells

– PROKARYOTIC cells lack the kinds of membrane-enclosed organelles found in eukaryotic cells

EUKARYOTIC CELL

Membrane

Cytoplasm

Organelles

Nucleus (contains DNA) 1 µm

PROKARYOTIC CELL

DNA

(no nucleus)Membrane

Figure 1.8


• Adaptation – All living things respond

and adjust to the environment

– Organisms are open systems that interact with other organisms as well as the nonliving factors of an environment



A Closer Look at Adaptation of Biological Systems

• Biological systems are much more than the sum of their parts

– A system is a combination of components that form a more complex organization

– Due to increasing complexity new properties emerge with each step upward in the hierarchy of biological order: EMERGENT PROPERTIES


Feedback Regulation in Biological Systems

• A kind of supply-and-demand adaptation that applies to some of the dynamics of biological systems

– Feedback mechanisms regulate biological systems, often the output or product of a process affects that very process.

• TWO types of feedback:

– Negative Feedback

– Positive Feedback


A closer look at Adaptation, continued

• Negative Feedback Response

– An accumulation of an end product slows the process that produces that product

B

A

C

D

Enzyme 1

Enzyme 1

Enzyme 2

Enzyme 3

DD D D

D

D

DD

DD

C

B

A Negative feedback

Figure 1.11


A closer look at Adaptation, continued

• Positive Feedback Response

– The end product speeds up production

WW

X

Y

Z

ZZ

ZZ

Z

Z Z Z

Z Z Z Z

Z

ZZ Z

ZZ

Y

X

Enzyme 4

Enzyme 5

Enzyme 6

Enzyme 4

Enzyme 5

Enzyme 6

Positivefeedback

Figure 1.12


Systems vs. Reductionism Biology

• Systems biology

– Seeks to create models of the dynamic behavior of whole biological systems

• With such models scientists will be able to predict how a change in one part of a system will affect the rest of the system

• Reductionism biology

– Involves reducing complex systems to simpler components that are more manageable to study


Reductionism breaks systems down into their parts

CELL

Nucleus

Cytoplasm

Outer membrane and cell surface

Figure 1.10


A closer look at Reductionism

• The study of DNA structure is an example of reductionism

– Understanding DNA has led to further study of heredity, such as the Human Genome Project

Figure 1.9


Lab: Scientific Investigations – Questions


Why study themes of Biology?

• Biology is Multidisciplinary

– Involves many different sciences: chemistry, ecology, physics, psychology, etc.

– is an ever expanding body of knowledge

– too much to memorize it all so need to generalize

– create a framework upon which to organize new knowledge

– themes are the key to understanding the nature of living organisms


• Eleven themes that unify biology


Themes of Biology – Science as a process of inquiry

• questioning & investigation

– Evolution

– Energy transfer

– Continuity & Change

– Relationship of structure to function

– Regulation

– Interdependence in nature

– Science, technology & society


• Energy Utilization – Activities of life require

organisms to perform work, which depends on an energy source

– The dynamics of any ecosystem include two major processes:• Cycling of nutrients • Flow of energy



• Metabolism – The sum of all the chemical

reactions carried out in an organism

A closer look at Energy Utilization


Producers

(plants and other

photosyntheticorganisms)

Consumers(including animals)

Sunlight

Chemical

energy

Heat

Heat

Ecosystem

Figure 1.4

• All organisms cycle nutrients such that energy flows through an ecosystem usually entering as sunlight and exiting as heat and often involves transformation of one form to another

A closer look at Energy Utilization


Evolution explains unity & diversity

• Unity- what do organisms have in common & why do similarities exist?

• common biochemistry & physiology

– evolutionary relationships connect all life through common ancestry

• Diversity - but why are there differences?

• adaptations allow different individuals to survive in different environments through natural selection


A closer look at Diversity

• Taxonomy

– Is the branch of biology that names and classifies species according to a system of broader and broader groups

Species Genus Family Order Class Phylum Kingdom Domain

Mammalia

Ursusameri-canus(Americanblack bear) Ursus

Ursidae

Carnivora

Chordata

Animalia

EukaryaFigure 1.14


A closer look at Diversity

• Life’s three domains: Prokaryotes vs. Eukaryotes

– Archea

– Eubacteria

– Eukarya

Figure 1.15

100 µm

0.5 µm

4 µmBacteria are the most diverse and widespread prokaryotes and are now divided among multiple kingdoms. Each of the rod-shapedstructures in this photo is a bacterial cell.

Protists (multiple kingdoms)are unicellular eukaryotes and their relatively simple multicellular relatives.Pictured here is an assortment of protists inhabiting pond water. Scientists are currently debating how to split the protistsinto several kingdoms that better represent evolution and diversity.

Kingdom Plantae consists of multicellula eukaryotes that carry out photosynthesis, the conversion of light energy to food.

Many of the prokaryotes known as archaea live in Earth‘s extreme environments, such as salty lakes and boiling hot springs. Domain Archaea includes multiple kingdoms. The photoshows a colony composed of many cells.

Kindom Fungi is defined in part by thenutritional mode of its members, suchas this mushroom, which absorb nutrientsafter decomposing organic material.

Kindom Animalia consists of multicellular eukaryotes thatingest other organisms.

DOMAIN ARCHAEA


A closer look at Unity in the Diversity of Life

• As diverse as life is there is also evidence of remarkable unity: cell structure, DNA, metabolism, etc

Cilia of Paramecium.The cilia of Parameciumpropel the cell throughpond water.

Cross section of cilium, as viewedwith an electron microscope

15 µm

1.0 µm

5 µm

Cilia of windpipe cells. The cells that line the human windpipe are equipped with cilia that help keep the lungs clean by moving a film of debris-trapping mucus upward.Figure 1.16


A closer look at Evolution

• The evolutionary view of life came into sharp focus in 1859 when Charles Darwin published On the Origin of Species by Natural Selection

– Descent with modification

– Natural selection

Figure 1.18Figure 1.19


A closer look at Natural Selection

• Darwin proposed natural selection as the mechanism for evolutionary adaptation of populations to their environments

Populationof organisms

Hereditaryvariations

Differences in reproductive success

Evolution of adaptationsin the population

Overproductionand struggle forexistence

Figure 1.20


• Natural selection is the evolutionary process that occurs when a population’s heritable variations are exposed to environmental factors that favor the reproductive success of some individuals over others

1 Populations with varied inherited traits

2 Elimination of individuals with certain traits.

3 Reproduction of survivors.

4 Increasing frequency of traits that enhance survival and reproductive success. Figure 1.21



Figure 1.22

• The products of natural selection are often exquisite adaptations of organisms to the special circumstances of their way of life and their environment

– All of life is connected through evolutionary history



• Many related organisms have very similar anatomical features, adapted for their specific ways of life

– Such examples of kinship connect life’s “unity in diversity” to Darwin’s concept of “descent with modification”

– “Form fits Function” at all levels of biological organization

Structure & Function Correlation

Large

ground finchSmallground

finchGeospiza

magnirostris

Seed eater

Sharp-beaked

ground finch

Camarhynchus

psitacula

Green

warbler

finch

Large

tree finchLarge cactusground finch

Ground finches Tree finchesInsect eaters Bud eater

Warbler finches

Common ancestor fromSouth American mainland

Gray

warbler

finchCerthidea

olivacea

Certhidea

fusca

Geospiza

difficilis

Cactus flowereater

Geospizascandens

Seed eater

Geospiza

conirostris

Geospiza

fortis

Mediumground

finch

Geospizafuliginosa

MangrovefinchCactospiza

heliobates

Cactospizapallida

Woodpecker

finch

Mediumtree finch

CamarhynchuspauperSmall tree finch

Vegetarianfinch

Camarhynchusparvulus

Platyspizacrassirostris

Cactusground finch

Figure 1.23



Lab: Scientific Investigations - Hypothesis


Lab: SciInvest - Prediction


Lab: SciInvest - Control


Scientific Inquiry

• The process of science includes observational-based discovery and the testing of explanations through hypothesis-based inquiry

– At the heart of science is inquiry: a search for information and explanation, often focusing on specific questions

– Biology blends two main processes of scientific inquiry

• Discovery science

• Hypothesis-based science


A closer look at Scientific Inquiry

• Discovery science

– Describes natural structures and processes as accurately as possible through careful observation and analysis of two types of data:

• Quantitative Data – uses measurements

• Qualitative Data – uses descriptors

Figure 1.24



• Two Types of Scientific Reasoning:

– Inductive Reasoning

• Scientists derive generalizations based on a large number of specific observations

– Deductive Reasoning

• Logic flows from the general to the specific



• In science, inquiry that asks specific questions usually involves the proposing and testing of hypothetical explanations, or hypotheses

– In science, a hypothesis is a tentative answer to a well-framed question, an explanation on trial that makes predictions that can be tested

• A scientific hypothesis must have two important qualities:

– It must be testable

– It must be falsifiable


A Closer Look at Scientific Inquiry

Observations

Questions

Hypothesis # 1:Dead batteries

Hypothesis # 2:Burnt-out bulb

Prediction:Replacing batterieswill fix problem

Prediction:Replacing bulbwill fix problem

Test prediction

Test does not falsify hypothesis

Test prediction

Test falsifies hypothesisFigure 1.25



• Experiments must be designed to test the effect of one variable by testing control groups and experimental groups in a way that cancels the effects of unwanted variables

– Science cannot address supernatural phenomena because hypotheses must be testable and falsifiable and experimental results must be repeatable

– A scientific theory is broad in scope; generates new hypotheses; and is supported by a large body of evidence



• Science is the search for knowledge

• Technology applies scientific knowledge for some specific purpose



• Science is a social activity characterized by cooperation and competition

Figure 1.31


Lab: SciInvest – Sample Experiment


Lab: SciInvest – Sample Experiment


Lab: Scientific Investigations - Procedure


Lab: SciInvest – Variables, cont’d


Lab: SciInvest – Procedure cont’d

LabBench–APLab #10

APLab: Cardiovascular Fitness

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