bio 2 ch1 notes

© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko

PowerPoint Lectures forCampbell Biology: Concepts & Connections, Seventh EditionReece, Taylor, Simon, and Dickey

CHAPTER 1Biology: Exploring Life

http://www.epa.gov/acidrain/

FIGURE 1.0_1 Chapter 1: Big Ideas

Themes in the Studyof Biology

The Processof Science

Biology andEveryday Life

Evolution, the CoreTheme of Biology

1.1 ALL FORMS OF LIFE SHARE COMMON PROPERTIES

Biology is the scientific study of life. Properties of life include

1. Order—the highly ordered structure that typifies life,

2. Reproduction—the ability of organisms to reproduce their own kind,

3. Growth and development—consistent growth and development controlled by inherited DNA,

4. Energy processing—the use of chemical energy to power an organism’s activities and chemical reactions,

© 2012 Pearson Education, Inc.

1.1 ALL FORMS OF LIFE SHARE COMMON PROPERTIES

5. Response to the environment—an ability to respond to environmental stimuli,

6. Regulation—an ability to control an organism’s internal environment within limits that sustain life, and

7. Evolutionary adaptation—adaptations evolve over many generations as individuals with traits best suited to their environments have greater reproductive success and pass their traits to offspring.


1.2 IN LIFE’S HIERARCHY OF ORGANIZATION, NEW PROPERTIES EMERGE AT EACH LEVEL

Biosphere

Madagascar

Ecosystem:Forest in

Madagascar

Community:All organisms in

the forest

Population:Group of ring-tailed

lemurs

Organism:Ring-tailed lemur

FIGURE 1.2_2

Organism:Ring-tailed lemur

Organ system:Nervous system

Organ:Brain

Tissue:Nervous tissue

Nerve

Spinal cord

Brain

Organelle:Nucleus

Cell:Nerve cell

Nucleus

Atom

Molecule:DNA

1.3 CELLS ARE THE STRUCTURAL AND FUNCTIONAL UNITS OF LIFE

Cells are the level at which the properties of life emerge.

A cell can regulate its internal environment, take in and use energy, respond to its environment, develop and maintain its complex organization,

and give rise to new cells.



All cells are enclosed by a membrane that regulates the

passage of materials between the cell and its surroundings and

use DNA as their genetic information.



There are two basic types of cells.1. Prokaryotic cells were the first to evolve, are simpler, and are usually smaller than eukaryotic cells. bacteria

2. Eukaryotic cells contain membrane-enclosed organelles, including a

nucleus containing DNA, and are found in plants, animals, and fungi.


FIGURE 1.3

Eukaryotic cell

Membrane

Prokaryoticcell

DNA(no nucleus)

Organelles

Nucleus(membrane-enclosed)

DNA (throughoutnucleus)

Cells illustrate another theme in biology: the correlation of structure and function.

Structure is related to function at all levels of biological organization.


1.4 LIVING ORGANISMS INTERACT WITH THEIR ENVIRONMENT, EXCHANGING MATTER AND ENERGY

Living organisms interact with their environments, which include other organisms and physical (non-living) factors.

In most ecosystems plants are the producers that provide the food, consumers eat plants and other animals, and decomposers act as recyclers, changing complex

matter into simpler mineral nutrients.


Figure 1.4Ecosystem

Sunlight

CO2

Heat

Chemical energy(food)

Producers(such asplants)

Water and mineralstaken up by tree roots

Cycling ofchemical nutrients

Decomposers(in soil)

Consumers(such asanimals)

CO2

O2O2

1.5 THE UNITY OF LIFE IS BASED ON DNA AND A COMMON GENETIC CODE

All cells have DNA, the chemical substance of genes.

Genes are the unit of inheritance that transmits

information from parents to offspring, are grouped into very long DNA molecules called

chromosomes, and control the activities of a cell.


1.5

A species’ genes are coded in the sequences of the four building blocks making up DNA’s double helix. All forms of life use essentially the same code to

translate the information stored in DNA into proteins.

The diversity of life arises from differences in DNA sequences.


1.6 THE DIVERSITY OF LIFE CAN BE ARRANGED INTO THREE DOMAINS

Diversity is the hallmark of life. Biologists have identified about 1.8 million species. Estimates of the actual number of species ranges

from 10 to 100 million. Taxonomy names species and classifies them

into a system of broader groups.


1.6 The diversity of life can be arranged into

three domains.

1. Bacteria are the most diverse and widespread prokaryotes.

2. Archaea are prokaryotes that often live in Earth’s extreme environments.

3. Eukarya have eukaryotic cells and include

single-celled protists and multicellular fungi, animals, and

plants.


FIGURE 1.6Domain Bacteria

Domain Archaea

Domain Eukarya

Bacteria

Archaea

Protists(multiple kingdoms)

Kingdom Fungi Kingdom Animalia

Kingdom Plantae

1.7 EVOLUTION EXPLAINS THE UNITY AND DIVERSITY OF LIFE

The history of life, as documented by fossils, is a saga of a changing Earth billions of years old and inhabited by an evolving cast of life forms.


1.7

In 1859, Charles Darwin published the book On the Origin of Species by Means of Natural Selection, which articulated two main points.1. A large amount of evidence supports the idea of

evolution, that species living today are descendants of ancestral species in what Darwin called “descent with modification.”

2. Natural selection is a mechanism for evolution.


1.11 EVOLUTION CONNECTION: EVOLUTION IS CONNECTED TO OUR EVERYDAY LIVES

Evolution is a core theme of biology. Evolutionary theory is useful in

medicine agriculture forensics Conservation

Human-caused environmental changes are powerful selective forces that affect the evolution of many species, including antibiotic-resistant bacteria, pesticide-resistant pests, endangered species, and increasing rates of extinction.


1.8 SCIENTIFIC INQUIRY IS USED TO ASK AND ANSWER QUESTIONS ABOUT NATURE

The word science is derived from a Latin verb meaning “to know.” Science is a way of knowing.

Science is a process not a thing.


1.8

How is a theory different from a hypothesis? A scientific theory is much broader in scope than a

hypothesis, usually general enough to generate

many new, specific hypotheses, which can then be tested, and

supported by a large and usually growing body of evidence.


SCIENTIFIC METHODOLOGY

• General Stages of Scientific Investigation

1. Asking a Question2. Collecting Information/Making

observations3. Inferring and forming a hypothesis4. Designing a controlled experiment to

test the hypothesis5. Collecting/Analyzing Data (qualitative

vs. quantitative)6. Drawing Conclusions

HOW DO WE MAKE A VALID HYPOTHESIS? Inference and imagination can lead to a

hypothesis.

If..then format Example:

If artificial king snakes are placed in an environment without coral snakes, then they will be attacked more frequently than the artificial brown snakes.

CONDUCTING A CONTROLLED EXPERIMENT Variables – factors that change

Independent – you manipulate (what you deliberately change)

Dependent – change in response to the independent variable (variable that is measured)

Control Group – used for comparison Nothing is changed

1.9 SCIENTISTS FORM AND TEST HYPOTHESES AND SHARE THEIR RESULTS

Case Study Scientists began with a set of observations and

generalizations poisonous animals are brightly colored and imposters resemble poisonous species but are

actually harmless. They then tested the hypothesis that mimics

benefit because predators confuse them with the harmful species.


1.9

The scientists conducted a controlled experiment, comparing an experimental group consisting of artificial

king snakes a control group consisting of artificial brown

snakes. The groups differed only by one factor, the

coloration of the artificial snakes. The data fit the key prediction of the mimicry

hypothesis.


Figure 1.9E

Coral snakespresent

Artificialking snakes

Artificialbrown snakes

84%

0

20

40

60

80

100

Coral snakesabsent

17% 16%

Per

cen

t o

f to

tal a

ttac

kso

n a

rtif

icia

l sn

akes

83%

1.9 SCIENTISTS FORM AND TEST HYPOTHESES AND SHARE THEIR RESULTS

Science is a social activity with most scientists working in teams.

Scientists share information in many ways. Science seeks natural causes for natural

phenomena. The scope of science is limited to the study of

structures and processes that we can directly observe and measure.


PRACTICE PROBLEM The graph below

shows the results of an experiment in which mice learned to run through a maze.

1. State the hypothesis that you think this experiment tested.

2. Identify the variables and control group.

3. What variables that must have been kept constant so as not to affect the results (validity).

4. Looking at the data collected, does it support the hypothesis? Explain.

1.10 CONNECTION: BIOLOGY, TECHNOLOGY, AND SOCIETY ARE CONNECTED IN IMPORTANT WAYS

Many issues facing society are related to biology. Most involve our expanding technology.

The basic goals of science and technology differ. The goal of science is to understand natural

phenomena.

The goal of technology is to apply scientific knowledge for some specific purpose.


1.10

Although their goals differ, science and technology are interdependent. Technological advances stem from scientific

research. Research benefits from new technologies.


YOU SHOULD NOW BE ABLE TO

1. Describe seven properties common to all life.

2. Describe the levels of biological organization from molecules to the biosphere, noting the interrelationships between levels.

3. Define the concept of emergent properties and describe an example of it.

4. Explain why cells are a special level in biological organization. Compare prokaryotic and eukaryotic cells.


YOU SHOULD NOW BE ABLE TO

5. Compare the three domains of life.6. Describe the process and products of

natural selection. 7. Distinguish between quantitative and

qualitative data.8. Distinguish between the scientific definition

and common use of the word theory. 9. Describe the structure of a controlled

experiment and give an example.10. Compare the goals of science and

technology. Explain why an understanding of science is essential to our lives.


bio 2 ch1 notes

Education

pearson education

diversity of life

properties of life

hallmark of life

history of life

eukaryotic cells

nucleus cell

forms of life use