01 intro sci evol-42 - biology things8/25/17 5 1.4 a control group establishes a baseline for an...

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Chapter 1 An Introduction to the Science of Life: •  1.1 Properties of life •  1.2 Levels of life •  1.3 Process of science •  1.4 Scientists try to control for variables •  1.5 Scientific thinking •  1.6 Tables and graphs •  1.7 Major themes in biology

© 2017 Pearson Education, Inc. Chapter Table of Contents

1.1 Opening Questions: What are the properties of life?

•  How would you determine if these objects were alive?

•  What properties would you require before you were willing to call it life?

Imagine that you are a future explorer and during a space voyage your team identifies a planet that has conditions favorable for life. Your first samples are microscopic, but return some interesting results, including objects with regular shapes.


1.1 Biology is the scientific study of life.

•  Biologists recognize life through a series of properties shared by all living things.

•  Biologists consider an object to be alive if, and only if, it displays all of these properties.


1.1 Properties of living things.

•  Reproduction: All organisms reproduce their own kind.

•  Growth and development: Information carried by genes controls the pattern of growth in all organisms.

Elephants only give birth to baby elephants—never baby lions.



•  Energy use: Every organism takes in energy, converts it to useful forms, and expels energy.

•  Order: Each living thing has a complex but well-ordered structure.



•  Cells: All living organisms consist of cells.

Some living organisms have just one cell.

Some living organisms have trillions of cells.

The cell is the fundamental unit of life.


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•  Response to the environment: All organisms respond to changes in the environment.

Many of these responses help to keep an organism’s internal environment within narrow limits.



•  Evolution: Individuals with traits that help them survive and reproduce pass the genes for those traits to offspring, driving the evolution of populations.

Elephants and woolly mammoths share a common ancestor. © 2017 Pearson Education, Inc. Chapter Table of Contents

1.2 Opening Question: What about a virus?

•  Using our criteria for living things, decide whether a virus is classified as alive.

•  Here are some fun facts: •  A virus cannot reproduce

on its own.

•  A virus is not composed of cells.

Would you consider a virus alive? © 2017 Pearson Education, Inc. Chapter Table of Contents

1.2 Opening Question: What about a virus?

•  Nonliving matter may display some of life’s properties. – Viruses show order for

example and can evolve. •  A virus doesn’t have ALL

of the properties of life. – Viruses do not have cells

and cannot reproduce on their own.

A virus is not alive.


1.2 Life can be studied at many levels.

The biosphere consists of all life on Earth.

An ecosystem consists of the living and nonliving components.



A community consists of all the interacting populations in an ecosystem

A population is a group of interacting individuals of one species.


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An organism is an individual living being.

An organ system is a group of organs that work together.



An organ consists of multiple tissues that cooperate to perform a specific task.

A tissue is an integrated group of similar cells that work together.



The cell is the fundamental unit of life.

An organelle is a component of the cell that performs a specific function.



A molecule is a group of atoms bonded together.

An atom is the fundamental unit of matter.


1.3 Opening Questions: What is the secret to the world’s best cookies? •  Are all chocolate chip cookies the same?

How do they differ? •  There are some outstanding chocolate

chip cookies out there! But, what makes a great cookie?

How do chocolate chip cookies vary? Do some taste better than others?


1.3 Science begins with observing the world. •  Scientists learn about the natural world by

making verifiable observations, taking measurements, and gathering data.

•  Observations lead a scientist to ask questions about the world.

Observation: Some cookies are better than others.


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1.3 Observations lead to explanations.

•  A hypothesis is a proposed explanation to a question that can be investigated.

•  Observations and experimentation are used to investigate hypotheses.

Question: What recipe makes the best cookies?

Hypothesis: Switching from butter to margarine will improve cookies.


1.3 Experiments provide data on the validity of the hypotheses. •  The scientific method

is a series of steps that can provide insight about the natural world.

•  In reality, real-world investigations are not rigidly linear.


1.3 Hypothesis vs. theory

•  A hypothesis is a proposed explanation for an observation.

•  A theory is a much broader explanation, well substantiated and comprehensive.

Endosymbiotic hypothesis Cell theory


1.4 Opening Questions: How does the term theory differ in science from everyday use?

Everyday Language: –  Conjecture –  Speculation –  Opinion

Scientific Language: –  Well supported –  Testable ideas –  Objective data

•  List at least three ways the term “theory” is used in everyday language. How do those contrast with the use of theory in scientific language?

Theory has a specific meaning in science. © 2017 Pearson Education, Inc. Chapter Table of Contents

1.4 Scientists try to control for variables.

•  In a controlled experiment, a test is run multiple times with only one variable changing.


1.4 Independent vs. dependent variables

•  The independent variable is what is being manipulated as a potential cause.

•  The dependent variable is the response, output, or effect under investigation.


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1.4 A control group establishes a baseline for an experiment. •  A negative control is a group for which

no change is expected. – Changing the oven

•  A positive control is a group for which a change is expected. – Doubling the amount of butter


1.4 Performing experiments blind can reduce bias. •  In a blind experiment,

information is withheld from participants (single-blind) or from both participants and experimenter (double-blind).

•  The placebo effect is a phenomenon in which a patient feels better after merely believing treatment was given, even if none actually was given.


1.5 Opening questions: What observations can you make about the natural world? •  You don’t have to travel to an exotic locale

to make observations.


1.5 Scientific thinking can be distinguished from other ways of viewing the world. •  Science is one way of

knowing the world. •  Science has hallmarks

and limitations. •  Pseudoscience is any

field of study that is falsely presented as having a scientific basis.


1.5 Indicators to recognize pseudoscience

Biology is limited to the study of life through recognized scientific approaches.


1.5 The scientific process depends upon peer review. •  Peer review is the

evaluation of work by impartial, qualified, often anonymous experts who are not involved in that work.

•  Through peer review, outside authorities can help verify the validity of scientific results.


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1.5 For reliability, consider the source of the information. •  A primary source is

original material presented for the first time by the person who performed the research.

•  A secondary source is a description or review of primary sources, often containing commentary.

Examples of primary sources are peer-reviewed journal articles, technical reports, and dissertations

Examples of secondary sources are websites, books, newspapers, encyclopedias, and magazines.


1.6 Opening Questions: Which cookie wins?

•  As part of a local “bake-off,” 100 students were asked to taste two cookies and choose a winner. Is there a clear winner?

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Cookie A Cookie B

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Cookie Bake-off


1.6 Scientists communicate data using tables and graphs. •  A scientific table is an

efficient way to present a lot of data in a small amount of space.

•  Graphs are a means of displaying data visually, which can help to summarize and compare information.


1.6 Tables are read in columns and rows.


1.6 Different graphs are used to present specific kinds of data.

Bar Graph

Line Graph

Pie Chart


1.7 Opening Questions: How can we explain both the unity and diversity of life? •  What are some things that

all living things have in common? – Describe as many features

as you can. •  How do living things differ

from each other? – Describe as many ways as

you can.


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1.7 Major themes underlie the study of biology at all levels. •  Focusing on these themes helps us organize

and make sense of all the information in biology.

Structure and function

Information Flow

Energy and Matter Pathways Evolution

Interconnections


•  Evolution, the descent with gradual modifications of ancestral species to modern-day ones, explains the common characteristics throughout living things.

1.7 The theory of evolution through natural selection is biology’s unifying theme.

Evolution through natural selection helps to explain the development of antibiotic-resistant bacteria.


1.7 Structure and function correlate at all levels of biological organization. •  Within biological systems, structure (the

shape of something) and function (what it does) often provide insight into each other.

The millions of tiny sacs in your lungs provide a structure that correlates with the function of gas exchange.


1.7 Living organisms regulate the transformation of energy and matter. •  All activities of the cell require energy and

matter to proceed.

The sun provides the energy that drives nearly every ecosystem.


1.7 Information flow is apparent at all levels of biological organization. •  The information in all genes is encoded in

an identical chemical language common to all organisms.

•  Many inherited diseases result from improper information in the form of a gene mutation.

People with Parkinson’s disease have a gene with faulty information.


1.7 The interconnections within and between the levels of biological systems •  There are many interconnections within

and between the different levels of biological systems.

•  At each new level, novel properties emerge that are absent from the preceding one.

A cell displays as emergent, which is not apparent in the individual parts that make up the cell.


01 intro sci evol-42 - biology things8/25/17 5 1.4 a control group establishes a baseline for an...

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