Interest Grabber
Section 1-3
Shells and Snowflakes
How can we distinguish between living and nonliving things, such as a
radiolarian (left) and a snowflake (right)? A radiolarian is a tiny living
thing that is covered with a glasslike shell and lives in the ocean. A
snowflake is a crystal made of frozen water.
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Section:
Interest Grabber continued
Section 1-3
Work with a partner to answer the following questions.
1. What are some similarities between the snowflake and the glass shell of
the radiolarian?
2. What are some differences between the snowflake and the glass shell?
3. Would you classify the shell as a living thing or a nonliving thing? Explain
your answer.
Go to
Section:
Characteristics of Living Things
Section 1-3
Characteristic
Examples
Living things are made up of units called
cells.
Living things reproduce.
Living things obtain and use materials and
energy.
Many microorganisms consist of only a single cell.
Animals and trees are multicellular.
Maple trees reproduce sexually. A hydra can
reproduce asexually by budding.
Flies produce flies. Dogs produce dogs. Seeds from
maple trees produce maple trees.
Flies begin life as eggs, then become maggots, and
then become adult flies.
Plants obtain their energy from sunlight. Animals
obtain their energy from the food they eat.
Living things respond to their environment.
Leaves and stems of plants grow toward light.
Living things maintain a stable internal
environment.
Despite changes in the temperature of the
environment, a robin maintains a constant body
temperature.
Taken as a group, living things change
over time.
Plants that live in the desert survive because they have
become adapted to the conditions of the desert.
Living things are based on a universal
genetic code.
Living things grow and develop.
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Section:
Characteristics of Life
1.Made up of cells
2.Reproduce
3.Based on Genetic Code
4.Grow and Develop
5.Use Energy or materials
6.Respond to the Environment
7.Maintain Internal Balance
8.Evolve.
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Section:
Make up of Cells.
Living things are made up of small self-contained units
called cells.
Cell- A collection of living matter enclosed by a barrier
that separates the cell from its surroundings.
They are the smallest units of an organism that can be
considered alive.
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Section:
Reproduction
Sexual Reproduction- two cells from different parents
unite to produce the first cell of the new organism
Asexual Reproduction- new organism has a single
parent. A single-celled organism divides in half to form
two new organisms.
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Section:
Genetic Code
The Genetic code such as DNA explains how
organisms inherit traits.
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Section:
Growth and Development
All living things grow. Bacteria enlarge or get bigger.
Some living things go from swimming with
gills(tadpoles) to hopping on land(frogs).
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Section:
Need materials and energy
Metabolism- combination of chemical reactions through
which an organism builds up or breaks down materials
as it carries out its life processes.
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Section:
Response to the Environment
Organisms detect and respond to stimuli from their
environment.
Stimulus- a signal to which an organism responds.
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Section:
Maintaining Internal balance
Homeostasis-process of keeping internal conditions
like temperature and water content fairly constant to
survive.
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Section:
Evolution
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Section:
Figure 1-21 Levels of Organization
Section 1-3
Biosphere
The part of Earth
that contains all
ecosystems
Biosphere
Ecosystem Community and
its nonliving
surroundings
Hawk, snake, bison, prairie dog, grass, stream, rocks, air
Community Populations that
live together in a
defined area
Hawk, snake, bison, prairie dog, grass
Population
Group of
organisms of one
type that live in
the same area
Bison herd
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Section:
Figure 1-21 Levels of Organization continued
Section 1-3
Organism Individual living
thing
Bison
Tissues, organs,
Groups of and organ systems
Cells
Brain
Nervous tissue
Cells
Nervous system
Smallest functional
unit of life
Nerve cell
Groups of atoms;
smallest unit of
Molecules most chemical
compounds
Go to
Section:
Water
DNA
Interest Grabber
Section 1-4
Putting Size in Perspective
Here are some measurements:
A young child is just over 1 m in height. The marble in the child’s hand
has a diameter of about 0.01 m. A cell in the palm of the child’s hand
has a diameter of about 0.0001 m.
How can you put these numbers in perspective? You can use a ratio
of the larger object to the smaller one. This requires dividing the larger
number by the smaller number. Another way to compare these
numbers is to look at the place value of the number 1. Each time the
number shifts one place value to the right, it decreases by a factor of
10. Thus, 1 is ten times greater than 0.10, and 10 is one hundred
times greater than 0.10.
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Section:
Interest Grabber continued
Section 1-4
1. How does the height of the child compare to the diameter of
the marble?
2. How does the marble diameter compare to the diameter of the cell?
3. How does the height of the child compare to the diameter of the cell?
Go to
Section:
Section Outline
Section 1-4
1–4
Tools and Procedures
A. A Common Measurement System
B. Analyzing Biological Data
C. Microscopes
1. Light Microscopes
2. Electron Microscopes
D. Laboratory Techniques
1. Cell Cultures
2. Cell Fractionation
E. Working Safely in Biology
Go to
Section:
Making a Graph From A Data Table
Section 1-4
Time
Absorbed
by Roots
(g/h)
Released
by Leaves
(g/h)
8 AM
10 AM
12 PM
2 PM
4 PM
6 PM
8 PM
1
1
4
6
9
14
10
2
5
12
17
16
10
3
Go to
Section:
Relative Rates (g/h)
Water Released and Absorbed by Tree
20
Water released by leaves
15
10
5
Water absorbed by roots
0
8 AM 10 AM 12 PM 2 PM 4 PM 6 PM 8 PM
Time
Videos
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It’s Alive!, Part 1
It’s Alive!, Part 2
Video 1
It’s Alive!, Part 1
Click the image to play the video segment.
Video 2
It’s Alive!, Part 2
Click the image to play the video segment.
Go Online
The latest discoveries in humanity’s effects on the world
Links from the authors on science and ethics
Interactive test
Articles on the nature of science
For links on experimenting, go to www.SciLinks.org and enter the Web
Code as follows: cbn-1012.
For links on microscopes, go to www.SciLinks.org and enter the Web
Code as follows: cbn-1014.
Interest Grabber Answers
1. Working with a partner, think of several questions that a scientist might ask
in order to understand why there are fish fossils in the desert of Wyoming.
Write these questions on a sheet of paper.
What other kinds of fossils have been found here? Is there evidence that a
lake or inland sea existed in Wyoming at the time the fish lived here?
2. Discuss your questions with your partner, and suggest a possible answer to
each question.
Students may not be able to suggest answers for all of their questions.
Students may know that most fish fossils formed in layers of mud and sand,
which is evidence that the area was once under water.
3. How could a scientist go about finding an answer to each of the questions?
Scientists would have to dig to look for more fossils and catalog what is
found in the same layers with the fish. Geologists would have to map the
fossil deposit and look for evidence of a lake shore or inland sea.
Interest Grabber Answers
1. Formulate a hypothesis that might explain the presence of the
“worms” in the container.
Students may say that the “worms” are immature beetles, or that there might
have been worm eggs or worms in the oatmeal.
2. How could you test your hypothesis?
If students thought that the worms were immature beetles, they may suggest
isolating some of the worms to see if they develop into beetles. If students
thought that there were eggs in the oatmeal, they may suggest taking a
fresh sample of the oatmeal to see if worms hatch in it.
3. Identify the variables in your proposed experiment. Identify the control in
your proposed experiment.
Student answers should indicate that the control remains unchanged and is
a standard of comparison. Variables are the factors that are subject to
change.
Interest Grabber Answers
Work with a partner to answer the following questions.
1. What are some similarities between the snowflake and the
glass shell of the radiolarian?
Both are tiny; both look crystalline.
2. What are some differences between the snowflake and the
glass shell?
Possible answer: The snowflake was not formed by a living thing, but the
glass shell was.
3. Would you classify the shell as a living thing or a nonliving
thing? Explain your answer.
Students will likely say that the shell is nonliving, although it once
surrounded the living thing that formed it.
Interest Grabber Answers
1. How does the height of the child compare to the diameter of
the marble?
The child’s height is 100 times the diameter of the marble.
2. How does the marble diameter compare to the diameter of the cell?
The diameter of the marble is 100 times the diameter of the cell.
3. How does the height of the child compare to the diameter of the cell?
The height of the child is 10,000 times the diameter of the cell.
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