LOUISIANA 7
Science
iLEAP
iLEAP
Practice
and
Mastery
iLEAP
iLEAP
iLEAP
iLEAP
Louisiana
iLEAP
iLEAP
iLEAP
iLEAP
iLEAP
iLEAP
To the Student
This book provides practice with the science
skills that students in grade 7 should master.
The book has three practices. Each practice
contains 48 multiple-choice questions from
three key categories of science: Science as Inquiry;
Life Science; and Science and the Environment.
Your teacher will explain how to complete
each practice. Before you begin working,
cut out the Answer Document from the back
of this book, and staple the pages together.
You will use the Answer Document to record your
answers. Remember to fill in the answer circles
completely. If you change an answer, fully erase
your first answer.
To help you choose the best answer to
a question, use the following tips:
•
Read each question carefully before you try
to answer it.
•
Think about what the question is asking.
Then answer the question.
•
Look at all the answer choices. Cross out any
choices that you know are wrong. Think about
the answer choices that are left. Choose the
one that you think is correct.
•
Check your answer to be sure it makes sense.
CONTENTS
PRACTICE 1
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PRACTICE 2
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12
PRACTICE 3
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23
1
Answer Document
PRACTICE 1 . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .
1
Answer Document
PRACTICE 2 . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .
2
Answer Document
PRACTICE 3 . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .
3
ISBN 978-0-7609-5213-9
©2008—Curriculum Associates, Inc.
North Billerica, MA 01862
No part of this book may be reproduced by any means
without written permission from the publisher.
All Rights Reserved. Printed in USA.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
LOUISIANA Practice and Mastery Science - Book 7—www.curriculumassociates.com—800-225-0248
PRACTICE 3
Directions: Answer questions 1 through 48. Mark your answers on page 3
of your Answer Document.
3 Which statement best describes the processes
of photosynthesis and respiration in the
carbon cycle?
Use the map to answer question 1.
The Main Land Biomes
A
B
C
D
A B C D
They are opposite and complementary
processes in the cycle.
They are parallel processes that accomplish
the same step in the cycle.
They are opposing processes that stop
the cycle from functioning.
They are unrelated processes that function
in different ways during the cycle.
Use the picture to answer question 4.
1 What letter on this map labels the coniferous
forest biome?
A
B
C
D
the letter A
the letter B
the letter C
the letter D
2 Which of these best explains why it is important
in a scientific experiment to test the hypothesis
more than once?
A
B
C
D
4 Which statement is the most accurate concerning
the inherited traits of these two plants?
The results of many trials need to be
consistent before the hypothesis is accepted.
Another scientist may have already
supported the hypothesis with a single trial.
The more trials that are performed, the
more likely the results will support the
hypothesis rather than negate it.
Testing the hypothesis with many trials
provides work for scientists.
A
B
C
D
They must have the same phenotypes
and the same genotypes.
They must have different genotypes
and different phenotypes.
They must have the same phenotypes,
but they could have different genotypes.
They must have the same genotypes,
but they could have different phenotypes.
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LOUISIANA Practice and Mastery Science - Book 7—CURRICULUM ASSOCIATES®, Inc.—www.curriculumassociates.com—800-225-0248
Use the data table to answer question 5.
6 Biologists are researching some different
animals that have a special ability: these
include starfish, planaria, earthworms, and
salamanders. What benefit to society are these
biologists most likely hoping to achieve?
Seed Germination
Flower Plant
Number
of Seeds
Planted
Sunlight
Hours
(day)
Water mL
(day)
Number
Number
of Seeds of Days to
Germinated Germinate
Calendula 1
8
8
50
8
10
Calendula 2
8
8
50
7
9
Calendula 3
8
6
50
6
12
Calendula 4
8
6
50
4
13
Calendula 5
8
3
50
2
15
Calendula 6
8
3
50
1
16
A
B
C
D
5 For this experiment, which list names an
independent variable (I), a dependent variable (D),
and a controlled factor (C)?
A
B
C
D
a way for humans to live underground for
part of the year
the ability of humans to live in or on the ocean
the ability of humans to regenerate body parts
a way for humans to live successfully in
densely populated regions
7 By what means can nitrogen gas in
the atmosphere enter the food web as part
of the nitrogen cycle?
I: type of plant
D: hours of sunlight/day
C: water/day
A
B
C
I: hours of sunlight/day
D: number of seeds germinated
C: number of seeds planted
D
by bacteria that convert nitrogen
to ammonia and by lightning
by certain green plants and by sunlight
by the breathing of animals and the
respiration of plants
by dispersal in plant roots and as a waste
product of photosynthesis
I: hours of sunlight/day
D: water/day
C: calendula plant
8 Gwen has been observing two breeds of horse
and taking notes on her observations.
Breed 1 stands taller and more upright
than breed 2.
Breed 1 has even coloring and a smooth coat,
while breed 2 is splotchy with a thick coat.
Breed 1 has stronger legs and a sleeker body
than breed 2.
Breed 1 must have been selectively bred
for racing.
I: number of seeds germinated
D: number of seeds planted
C: number of days for germination
•
•
•
•
Which note is an inference?
A
B
C
D
note 1
note 2
note 3
note 4
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LOUISIANA Practice and Mastery Science - Book 7—CURRICULUM ASSOCIATES®, Inc.—www.curriculumassociates.com—800-225-0248
11
Use the graph to answer question 9.
Co2 Concentration (ppm, or parts per million)
CO2 in the Atmosphere
Which statement best outlines an essential
truth about biotic and abiotic factors?
A
350
345
B
340
335
330
C
325
320
D
315
310
0
1960
1965
1970
1975
1980
1985
Organisms in an ecosystem can survive
without abiotic factors but not without
biotic factors.
Organisms in an ecosystem can survive
without biotic factors but not without
abiotic factors.
All biotic factors in an ecosystem depend
on abiotic factors.
All abiotic factors in an ecosystem depend
on biotic factors.
1990
The Increase of Atmospheric CO2 Since 1958
9
12
Which statement is an explanation rather
than a description based on the graph?
A
B
C
D
In 1965, the concentration of CO2
in the atmosphere was about 320 ppm.
Due to fossil fuels, industry,
and agriculture, CO2 is increasing
in the atmosphere.
Between 1960 and 1990, CO2 steadily
increased in the atmosphere.
A measurement used for CO2 in the
atmosphere is parts per million, or ppm.
A
B
C
D
13
10
In what way has the development of advanced
transportation methods most affected the way
people eat?
A
B
C
D
A scientist found that a certain kind of flower
plant attracted many aphids. She counted the
aphids on each plant leaf and obtained the
following results: 26, 29, 46, 21, 33, 20, 12, 27,
26, 30. Which of these is the mode?
Two main types of plants have a life cycle that
includes a seed stage. Where can seeds be
found in most nonflowering plants?
A
B
C
D
People can go to local restaurants more often.
People can get local produce more quickly.
People can eat fresh food from around
the world.
People can take food with them on long trips.
46
27
26.5
26
on the needles
in the stem
in a female cone
in the fruit
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LOUISIANA Practice and Mastery Science - Book 7—CURRICULUM ASSOCIATES®, Inc.—www.curriculumassociates.com—800-225-0248
16
Use the diagram to answer question 14.
Photosynthesis
M O
Q
Some ranchers want to eliminate wolves
and coyotes in an ecosystem because these
animals sometimes prey on the ranchers’
sheep. What is the most likely result of
eliminating these predators?
A
P
B
N
C
D
14
Which statement describes Step Q?
A
B
C
D
17
Oxygen combines with carbon dioxide
in the leaf.
Chlorophyll captures sunlight and oxygen.
Solar energy splits water into hydrogen
and oxygen.
Oxygen from a chemical reaction passes
out of the leaf.
Which of these is an example of sexual
reproduction?
A
B
C
D
15
Producers in the ecosystem could
overpopulate and then die out from lack
of resources.
Other predators in the ecosystem could
weaken due to lack of competition with
the wolves and coyotes.
The natural prey of these animals could
drastically overpopulate, depleting natural
food supplies and damaging crops.
The ranchers’ sheep could easily wander off
and destroy the grasslands that sustain them.
A fungi gives off spores that grow into
new plants.
Two parents each contribute a cell for
a new organism.
A part of a parent cell breaks off to grow
into an adult organism.
A single cell splits into two new cells.
Which of these represents a level of
organization from most diverse to least diverse?
A
B
C
D
biosphere → ecosystem → population →
community
ecosystem → biosphere → population →
community
community → biosphere → ecosystem →
population
biosphere → ecosystem → community →
population
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18
20
A biologist is watching the movement of a
group of jaguars at night. Which tool will best
help the biologist keep track of the animals on
a night without moonlight?
A
B
C
D
dark glasses
telescope
binoculars
infrared camera
Because doctors can see viruses, bacteria,
and molds that cause disease, Milos believes
that no one ever needs to be made sick by
these organisms again. Which statement best
explains why Milos is wrong?
A
B
Use the Punnett square to answer question 19.
B
C
B
D
B
Diseases are caused by many more
organisms than viruses, bacteria,
and molds.
No technology exists yet to explain
why people can be exposed to the same
disease-causing organisms, but not have
the same response.
Doctors can see viruses, bacteria, and
molds, but they do not know what
particular disease each of these causes.
People get very different diseases from
different combinations of viruses, bacteria,
and molds.
b
B = bright-blue flowers (dominant trait)
b = purple flowers (recessive trait)
19
21
A
What percent of the offspring from the
cross shown above will be expected to have
purple flowers?
A
B
C
D
Which of these best defines carrying capacity?
B
0%
25%
50%
75%
C
D
the largest number of a given species
that can be supported stably in a given
ecosystem
the largest number of a given species that
has ever lived in a given ecosystem
the largest range in the number of a given
species that can be supported stably in a
given ecosystem
the largest number of a given species that
can avoid predation in a given ecosystem
27
LOUISIANA Practice and Mastery Science - Book 7—CURRICULUM ASSOCIATES®, Inc.—www.curriculumassociates.com—800-225-0248
Use the diagram to answer question 22.
Use the diagram to answer question 24.
Series of Steps
Parent cell
Daughter cells
22
The structure of this organ allows it to move
fluids through the body. Which system and
function relate to this organ specifically?
A
B
C
D
24
respiratory system—drawing oxygen into
the body and releasing carbon dioxide
digestive system—moving liquefied food
through the body to cells that change the
food to a form the body can use
circulatory system—pumping oxygen
rich blood to cells and removing excess
carbon dioxide
skeletal system—allowing for the motion of
the body through joints with synovial fluid
A
B
C
D
25
23
Which of these is a natural resource that is
most immediately affected by pollutant gases
in an ecosystem?
A
B
C
D
What is a purpose of the kind of cell division
shown in the diagram?
plants
water
soil
air
to create two new sex cells with different
characteristics
to allow for growth and to replace dead
or injured cells
to grow larger cells
to split the nucleus of one cell in half
to make two cells
Jan’s teacher told her that a salt solution will
harm the growth of a certain plant and prove
that some plants only grow well in fresh water.
Jan carried out an investigation, but her plant
does not die. Which action would be best for
her to take?
A
B
C
D
Repeat the experiment and if the results
are the same, report these findings to
the teacher.
Discard the healthy plant and report that
the salt water did harm her plant’s growth.
Based on this trial, report that salt water does
not harm the growth of this type of plant.
Give up on the lab, and use another
student’s results that more closely match
what the teacher said would happen.
28
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26
Water from a stream is diverted by a beaver
dam before it reaches the freshwater pond
it normally refilled. The pond dries up quite
quickly. Which pond animal would be most
affected by this change?
A
B
C
D
Use the data table to answer question 28.
Squirrel Population in Clay’s Backyard
a great blue heron
an adult green tree frog
a muskrat
a freshwater trout
Month
Number of Squirrels
June
9
July
11
August
8
September
10
October
7
November
9
December
2
January
1
Use the graphs to answer question 27.
35
35
30
30
25
20
15
20
15
10
5
5
1
2
3
Counts
27
25
10
0
4
28
After Hunting Season
Number of Deer
Number of Deer
Before Hunting Season
0
A
1
2
3
B
4
Counts
C
The town of Carson is considering whether
to limit or ban deer hunting in Westward Park.
Which statement best describes the results
of this investigation?
A
B
C
D
Clay did a count of squirrels in his backyard for
8 months. He averaged the number of squirrels
he counted each day to get a count for the
month. At the end of his study in January, he
concluded that almost all the squirrels had
been eaten by predators. What is another
reasonable explanation for Clay’s data?
D
No significant decrease in deer population
is caused by deer hunting.
The results indicate that deer hunting
should be extended for a longer period
of time each year.
Counts of deer population after the
hunting season are inaccurate.
Deer hunting endangers the deer
population in the park.
The squirrels became nocturnal during
the colder months.
The squirrels chased each other out
of the yard in December and January.
The squirrels remained mostly in their
burrows during the colder months
of December and January.
The squirrels had an overabundance
of food in the region from November
through January.
29
LOUISIANA Practice and Mastery Science - Book 7—CURRICULUM ASSOCIATES®, Inc.—www.curriculumassociates.com—800-225-0248
29
Professor Anne Gordon has discovered what
she believes to be a new microorganism in her
laboratory. Which of the following is the most
appropriate response she can take regarding
her discovery?
A
B
C
D
30
31
Vacuoles in plant cells can be different from
vacuoles in animals cells. In what way can
they be different?
A
B
C
Begin working immediately to see how
the microorganism reproduces.
Communicate with other biologists about
her discovery.
Begin a long paper that she will publish
in several years when she is finished
with her research.
Dispose of the microorganism and
continue with other research.
D
A plant cell’s vacuole is used for storage.
A plant cell’s vacuole has a cell wall.
A plant cell’s vacuole may be central
and larger.
A plant cell’s vacuole contains chloroplasts.
Use the maps to answer question 32.
1979
A population of cactus is planted in a
marshland ecosystem in Louisiana. Which
statement best describes what will most likely
happen in the ecosystem?
A
B
C
D
The ecosystem will change very little
because the cacti will not be able to survive.
The cacti will grow well and spread, taking
over the marshland and using up the water.
The cacti will reproduce much more
rapidly than normal and replace all the
native marshland vegetation.
The cacti will grow taller than normal to
reach above the water for sunlight and air.
2006
32
The maps show changes to the ice structure
of the region of the North Pole. Which of the
following best explains the change in the region
between 1979 and 2006?
A
B
C
D
an increase in volcanic activity brought
about by tectonic plate shifting
an increase in average global temperature
brought about by technological activities
an increase in precipitation brought about
by a normal variation in climate
a decrease in the volume of ocean water
brought about by human use
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33
A
B
C
D
34
Which of these is an ability that a newborn
human infant has?
A
B
C
D
100 individuals
400 individuals
800 individuals
1,600 individuals
the ability to use very simple words
the ability to turn over
the ability to communicate some needs
the ability to walk
Use the diagram to answer question 37.
Which statement is a fact about structural
adaptations?
A
B
C
D
35
36
The population of a community begins with a
first generation of 100 individuals. Assuming
an equal balance of males and females and no
deaths, each pair of individuals produces two
offspring each year. Offspring can produce a
year after birth. What will most likely be the
total number in the community in 3 years?
Structural adaptations are always visible.
Structural adaptations occur when an
organism needs to change the way it acts,
or behaves.
Structural adaptations are never visible.
Structural adaptations involve physical
ways organisms are suited to their
environment.
Maxine measures the mass of a hummingbird.
Which metric unit should she use to express
her results?
A
B
C
D
37
micrograms
grams
kilograms
milliliters
Which animal will be threatened most quickly
if the population of snakes in the habitat
severely decreases?
A
B
C
D
frog
hawk
owl
mouse
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LOUISIANA Practice and Mastery Science - Book 7—CURRICULUM ASSOCIATES®, Inc.—www.curriculumassociates.com—800-225-0248
38
Yolanda and Greg’s teacher has asked them,
What shape of feeder will work best to feed
mealworms to bluebirds? Yolanda makes her
feeder with a flat plate hanging from wires.
Greg makes his feeder from a rectangular box
with steep sides, set on a platform. Which
statement best describes how well Yolanda’s
and Greg’s plans will work?
A
B
C
D
39
40
Nutrients are needed by the body for energy
and cell growth and repair. What most likely
happens if a person’s diet lacks certain nutrients?
A
B
C
Greg’s feeder is a better design because
the worms will not crawl away.
Yolanda’s feeder is a better design because
the birds will be able to get the worms
more easily.
Neither feeder is the right shape for
a feeder to hold mealworms.
Both feeders will be shaped well to hold
mealworms for bluebirds.
D
Use the data table to answer question 41.
Left-Brain and Right-Brain Dominance
Classmate
Behavior
Dominance
1
left leg on top
right brain
2
left leg on top
right brain
3
right leg on top
left brain
4
right leg on top
left brain
5
left leg on top
right brain
What is the relationship between osmosis
and diffusion?
A
B
C
D
The person becomes ill.
The body works extra hard to produce
those nutrients from other nutrients
that are being consumed.
The person will be unable to exercise
effectively.
Certain functions of the body may
be mildly to seriously impaired.
Diffusion takes place only in cells, whereas
osmosis takes place in cells and in various
kinds of solutions.
Osmosis is a special type of diffusion that
occurs only when water molecules move
across a membrane.
Diffusion is a special type of osmosis that
occurs only when fluids enter and exit a cell.
Diffusion generally occurs from an area
of greater concentration to one of lesser
concentration, whereas osmosis generally
occurs from lesser concentration to greater.
41
Without explaining the test, Thelma
determined whether classmates were rightbrain or left-brain dominant by having them
cross their legs. Thelma concluded that if her
test is valid, right-brain dominance and leftbrain dominance are about equal across the
world’s population. Which of the following is
a problem with her investigation?
A
B
C
D
The phenomena of right-brain or left-brain
dominance could not possibly exist.
Thelma’s sample size was not large or varied
enough to reach the conclusion she did.
Thelma should have told her classmates
how the test worked before having them
cross their legs.
Thelma should have made sure that all
of the classmates in her test were either
males or females.
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LOUISIANA Practice and Mastery Science - Book 7—CURRICULUM ASSOCIATES®, Inc.—www.curriculumassociates.com—800-225-0248
42
Only a small population of plants survive on
the rocks in a tundra ecosystem. Which factor
most likely limits the population?
A
B
C
D
43
Use the dichotomous key to answer question 44.
Birds at Zoo Park
extreme temperatures
lack of producers
air quality
volcanic eruptions
Which of these gives the set of steps that occur
during respiration in plants?
A
B
C
D
1 Molecules of glucose are broken down
by a series of chemical reactions that
require light energy from the sun.
2 Some of the energy stored in glucose
is taken in as heat but most is stored
in ATP.
3 Carbon dioxide and water are given
off as waste products.
1 Carbon dioxide and water take in light
energy to stimulate a chemical reaction.
2 In a series of steps, sugar and oxygen
are formed.
3 Sugar is stored in the cells, and oxygen
is released.
1a.
can fly
Go to 2.
1b.
cannot fly
kiwi
2a.
has a long, strong beak
Go to 4.
2b.
does not have a long, strong beak
Go to 3.
3a.
has a cone-shaped beak
rose- breasted
grosbeak
3b.
has a long, thin beak
ruby- throated
hummingbird
4a.
has 4 toes arranged in a yoke
Go to 5.
4b.
has fewer than 4 toes
three-toed
woodpecker
5a.
has a large crest
pileated
woodpecker
5b.
has no crest
Go to 6.
6a.
has a red head
red-headed
woodpecker
6b.
does not have a red head
yellow-shafted
flicker
44
Kelly constructed this dichotomous key to
help identify the birds at Zoo Park.
Which phrase describes a red-headed
woodpecker?
1 Molecules of glucose are broken down
by a series of chemical reactions that
require oxygen.
2 Some of the energy stored in glucose
is released as heat but most is stored
in ATP.
3 Carbon dioxide and water are given
off as waste products.
A
B
C
D
a bird with a long, strong beak; fewer than
4 toes; a large crest; and a red head
a bird that cannot fly; does not have a long,
strong beak; and has no crest
a bird that flies; has a long, strong beak; has
4 toes arranged in a yoke; and a red head
a bird with a long, strong beak; 4 toes
arranged in a yoke; a crest; and no red head
1 Carbon dioxide and water give off heat
energy during a chemical reaction.
2 The heat energy creates glucose that
is stored in ATP.
3 Water and hydrogen are given off as
waste products.
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45
Use the data table to answer question 48.
In a cross between a purebred yellow flower
and a purebred red flower, neither color trait
is dominant. Which of these is the most likely
outcome of such a cross?
A
B
C
D
Kingdom
all yellow flowers
all red flowers
half yellow flowers and half red flowers
all orange flowers
Characteristics
Monera
Protista
Fungi
unicellular
all
most
some
multicellular
none
some
most
has nucleus
none
all
all
producer
some
some
none
consumer
some
some
all
48
46
Which statement best describes a niche?
A
B
C
D
The role an organism plays in its habitat
is its niche.
The specific place an organism lives in
its habitat is its niche.
Several organisms in the same habitat
can share a niche.
Many different habitats make up a niche.
A biologist developed a kingdom table to
classify organisms as monera, protista, or fungi.
Which conclusion about classifying one of these
organisms is based on correct reasoning?
A
B
C
D
47
If the organism is multicellular, it should
be classified as fungi.
If the organism’s cell does not have
a nucleus, it must belong to the monera
classification.
If the organism is a producer, it is also
a protista.
If the organism is a consumer, it cannot
belong to the fungi classification.
Which question would be best answered
by a line graph?
A
B
C
D
What chemicals are involved in the
processes of photosynthesis and respiration?
What are some of the adaptations of leaves
that support the growth of a plant?
How does an elephant’s size change from
birth to old age?
What are the relative amounts of different
chemicals that make up the human body?
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LOUISIANA Practice and Mastery Science - Book 7—CURRICULUM ASSOCIATES®, Inc.—www.curriculumassociates.com—800-225-0248