GYMNOSPERMS VS.
ANGIOSPERMS
LIFE SCIENCE / HARD LEVEL
Introduction
There are two types of seed plants: gymnosperms, or “naked seed”
plants, and angiosperms, the flowering plants. Angiosperms have two
categories: monocots, which have one seed leaf, and dicots, which
have two. Scientists often use a dichotomous key to help identify an
organism based on its structure. In this experiment, you will use a
dichotomous key to identify a number of plants as gymnosperms or
angiosperms. You will also be able to narrow down the gymnosperms
to a particular plant and the angiosperms to whether they are a
monocot or a dicot.
Time Needed
Preparation: 15 to 30 minutes to collect plants
Completion: 30 minutes
What You Need
✎ variety of leaves (e.g., some needle-like ones,
✎
✎
✎
some flat, broad ones, etc.)
blade of grass (it is a type of leaf)
variety of flowers
pencil
Safety Precautions
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.
© 2004 Facts On File, Inc.
What You Do
1. Collect a variety of leaves and flowers as listed above.
2. Use the following dichotomous key (next page) to determine if
the plant is a gymnosperm or angiosperm, and what type. Always
start with number 1 on the key for each separate item.
3. Record your data on the data table.
4. Refer to diagrams in Figure 1 for clarification when necessary.
Data Table
Description
of item
Gymnosperm
or angiosperm
Which kind?
1
2
3
4
5
6
7
8
9
10
© 2004 Facts On File, Inc.
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.
DICHOTOMOUS KEY
1. Leaves are needle-like or scale-like
Leaves are flatter and have veins,
or it is a flower
gymnosperm, go to 2
angiosperm, go to 5
2. Leaves are just needle-like
go to 3
Leaves are both needle-like and scale-like juniper
Leaves are just scale-like
cedar, cypress
3. Needles are in groups of 2 or more
Needles are flattened and grow all
around the stem
Needles grow in two feather-like rows
along the stem
Needles are in 2 or 3 stiff rows
redwood, bald
cypress
hemlock, fir
4. Needles are in groups of 2, 3, or 5
Needles are in clusters on a short stem
pine
larch
5. It is a flower
It is a leaf
go to 6
go to 7
6. Petals are in multiples of 3
Petals are in multiples of 4 or 5
monocot
dicot
7. Leaf contains parallel veins
Leaf has branch veins
monocot
dicot
© 2004 Facts On File, Inc.
go to 4
spruce, Douglas fir
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.
parallel veins
branched veins
needle-like leaves
scale-like leaves
needle-like and
scale-like leaves
Figure 1
© 2004 Facts On File, Inc.
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.
needles are in groups
of 2 or more
needles are in groups
of 2, 3, or 5
needles are in clusters
on a short stem
needles are flattened or angular
and grow all around stem
needles grow in two feather-like
rows along stem
Figure 1 (continued)
© 2004 Facts On File, Inc.
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.
needles are in
2 or 3 stiff rows
Figure 1 (continued)
Observations
1. What characteristics did the gymnosperms have in common?
The angiosperms?
2. Which was easier to find, gymnosperms or angiosperms?
© 2004 Facts On File, Inc.
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.
JUNIOR SCIENCE EXPERIMENTS ON FILETM NEW EDITION
1.0 Safety Guidelines (page 1)
1.0 SAFETY GUIDELINES
GENERAL
obtain your teacher’s permission for experiments performed
• Always
at school, and your parent’s permission for experiments performed
at home, before attempting any experiment.
all instructions for an experiment several times before
• Read
starting the experiment, and follow the directions exactly as they
appear in this volume.
an experiment requires adult supervision, do not perform the
• Ifexperiment
unless you have an adult supervising you the entire
time you are performing the experiment.
your hands before the start of and after each experiment you
• Wash
perform.
• Keep your work area clean.
eat or drink while performing a lab experiment. Never taste a
• Never
substance used in an experiment unless you are told that it is safe
to do so.
aware of the location of safety equipment you may need in an
• Be
emergency, such as running water, an eyewash if you are at school,
and a fire extinguisher.
are going outside, make sure you have permission to go from
• Ifyouryouteacher
and parent. Take a buddy with you, and dress
appropriately for the weather. Make sure you or someone who
accompanies you is familiar with the area, and bring along a first-aid
kit in case of an emergency.
• Never look directly into the sun.
CHEMICAL SAFETY
wear goggles when working with chemicals, such as acids
• Always
and bases, and near heat sources like flames. If at all possible,
avoid wearing contact lenses when working with chemicals.
any substance gets into your eyes, notify an adult (e.g., your
• Ifteacher
or parent) immediately, and flush your eyes with running
water for at least 15 or more minutes. Do not mix chemicals unless
you are told to do so by a teacher or parent.
© 2004 Facts On File, Inc.
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.
JUNIOR SCIENCE EXPERIMENTS ON FILETM NEW EDITION
1.0 Safety Guidelines (page 2)
• Never touch, taste, or smell chemicals unless instructed to do so.
• Keep chemicals in closed containers when they are not in use.
of all used chemicals properly. Do not pour any chemicals
• Dispose
or solids down the drain unless instructed to do so.
safety gloves and a plastic apron when handling chemicals. If
• Use
any chemicals spill on your skin, rinse the affected area with
running water for at least 10 minutes, and notify your teacher or
parent immediately.
Take precautions to avoid spilling chemicals. If a chemical spills on
• any
surface, notify your teacher or parent immediately to assist with
clean-up.
caution when using sharp instruments such as knives or
• Exercise
scissors. Always cut away from yourself, not toward yourself. If you
cut yourself, notify your teacher or parent immediately.
GLASSWARE
• Clean glassware when you are finished with the experiment.
careful when using glassware. If a piece of glassware breaks,
• Be
have an adult assist you in clean-up to avoid injuries from broken
glass. Never use broken or damaged glassware.
FIRE SAFETY
not heat glassware that is not completely dry. Do not pick up hot
• Do
glassware without heat-resistant gloves or tongs.
heating glassware, keep it away from yourself and from
• When
others.
not heat anything unless instructed to do so by a teacher or
• Do
parent.
• Do not heat substances in a closed container.
an experiment, make sure that all heating sources are off and
• After
that all flames have been put out.
• Do not reach across such heating sources like flames.
© 2004 Facts On File, Inc.
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.
1.0 Safety Guidelines (page 3)
JUNIOR SCIENCE EXPERIMENTS ON FILETM NEW EDITION
have long hair, tie it back, out of the way. Do not wear clothing
• Ifwithyouloose
sleeves, scarves, bows, ties, or anything else that may
hang into a fire. Do not wear long earrings.
ELECTRICAL SAFETY
• Do not touch electrical equipment when your hands are wet.
not plug many electrical devices into one outlet or use an
• Do
extension cord.
© 2004 Facts On File, Inc.
Published by Facts On File, Inc.
All electronic storage, reproduction, or transmittal is copyright protected by the publisher.