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Worksheets8th Grade Q3 Science Review
Total questions: 70
Worksheet time: 35mins
Helen is studying the growth of two different types of plants. She planted two of each type of plant in locations with different levels of sunlight: full sun, partial shade, and full shade. For five weeks, Helen records the number of new leaves on each plant.
Which of the following statements correctly describes the independent and dependent variables in Helen's experiment?
The independent variable is the amount of sunlight, and the dependent variable is the number of new leaves.
The independent variable is the kind of plant, and the dependent variable is the amount of sunlight.
The independent variable is the amount of sunlight, and the dependent variable is the kind of plant.
The independent variable is the number of new leaves, and the dependent variable is the amount of sunlight.
The following bar graph shows the population of bacteria under different temperature ranges. What can be concluded about the bacteria from reading this graph?
They thrive at exactly 30°C.
They cannot tolerate temperatures above 50°C.
They prefer temperatures between 20°C and 30°C.
They prefer warmer temperatures to cooler temperatures.
Consider the following hypothesis, “Drinking too many soft drinks causes calcium deficiency in teens.” A scientist plans an experiment to test the hypothesis. What is the outcome variable (dependent variable)?
the type of soft drink consumed
the amount of soft drinks the teens drink
the number of teens in the test
the level of calcium in the teens
Ena is measuring the pH of various liquids to see if they are acids or bases. Although she is following the same procedure each time, she notices that when she tests a particular liquid she obtains a result she does not expect. She is not sure that the result is accurate.
What should Ena do to improve the reliability of the data she collects?
change her hypothesis
perform repeated trials on each liquid
measure a smaller volume of each sample
research more information about acids and bases
Why are replications of an experiment necessary?
to try different procedures
to test different equipment
to increase the number of variables
to ensure that the experiment is reproducible
A student is studying the reactivity of different metals in hydrochloric acid (HCl). The chart below was recorded after using each of the metals in different temperatures of the acid.
Which of these is the dependent variable in these tests?
bubbles
cold HCl
copper
warm HCl
Alita wants to know if the color of ice cream affects its taste. She has three batches of vanilla ice cream. Batch 1 has no food coloring, Batch 2 has red food coloring, and Batch 3 has green food coloring. She asks 10 people to taste the three batches of ice cream and choose their favorite. What is the independent variable in Alita's investigation?
color of the ice cream
taste of the ice cream
number of batches of ice cream
number of people tasting the ice cream
A biologist is investigating the effects of growth hormone on the rate of metamorphosis in butterflies.
Which of the following methods of investigation would work best for the biologist investigating any possible effects?
models
controlled experiments
systematic observations
random sampling of populations
Eduardo is a conservation biologist. He needs to develop a plan to preserve wetlands. He begins his project by studying the data in the following chart.
How is Eduardo using scientific methods in developing a plan?
He is analyzing a hypothesis about causes and effects.
He is proposing an experiment about causes and effects.
He is analyzing data about causes and effects.
He is using intuition to determine causes and effects.
Paul’s class investigated the effects of friction on the motion of a toy car. Using ramps with different surfaces, students determined the amount of time, in seconds (s), for the toy cars to reach the bottom of each ramp. All variables were controlled except the tested variable (independent variable). One group of students concluded that toy cars on a sandpaper surface are the fastest.
What conclusion should students make from their test based on the data?
The results support the conclusion.
The results fail to support the conclusion.
The conclusion is valid for the data recorded.
More data need to be added to the conclusion.
Unprotected exposure to the sun’s rays is a factor in the development of skin cancer. Which of the following is an example of empirical evidence that supports this hypothesis?
data demonstrating a relationship between amount of sun exposure and incidences of skin cancer
a model of a skin cell showing where DNA is in the cell
a skin cancer survivor’s recollection that he had a bad sunburn as a child
an advertisement for a sun block product that claims it protects skin for ultraviolet rays
Linus Pauling, who won the Nobel Prize in Chemistry, announced that he had found that taking massive doses of vitamin C could prevent and treat a cold. He based this claim on the results of a single trial on a group of school children at a skiing camp in the Swiss Alps. The children that were given 1 gram per day of vitamin C showed a significant decrease in frequency of colds compared to children at the same camp who were not given additional vitamin C.
Which of these statements correctly assesses Pauling's claim?
Pauling's claim must be correct because his evidence supported it.
Pauling's claim is not correct because he did not work with another scientist.
Pauling's claim must be correct because he won the Nobel Prize in Chemistry.
Pauling's claim is not correct because he did not gather enough empirical data.
These two diagrams show the history of cell-membrane models.
Which statement best describes the change in the cell-membrane model?
The new model was the result of a vote by scientists.
The new model helped scientists avoid more research.
The new model was based on the researchers’ best guess.
The new model came from more experiments and evidence.
Scientific models help scientists visualize phenomena that cannot be directly observed. Which model limitation most likely applies to a classroom model of the solar system?
It is not to scale.
It is two-dimensional.
The planets do not orbit.
The planets are not labeled.
The distances between objects in space are enormous. When miles are used to measure these distances, amounts can exceed millions. Therefore, distances in space are often measured in astronomical units (AU). The chart below provides the distances between the planets and the Sun, measured in both miles and astronomical units (AU). The units of measurement have been left off of the chart.
Which value represents the distance between Saturn and the Sun in astronomical units?
.39
886.7 million
9.539
36 million
Which measurement would best be used to describe the distance between Earth and a neighboring galaxy?
astronomical units
kilometers
light years
miles
The farthest galaxy discovered is 13.2 billion light-years away. Which statement best represents the number of galaxies in the universe?
There are hundreds of galaxies because the universe is very large.
There are billions of galaxies because they are far apart in a large universe.
There are millions of galaxies because some are close and some are far.
There are thousands of galaxies because they are spaced so far apart.
Which sentence is a true statement about the relationship between galaxies and stars?
A galaxy contains only one star.
A star contains only one galaxy.
A galaxy contains many stars.
A star contains many galaxies.
Which answer correctly orders astronomical bodies according to their distance from the Sun?
1.Venus
2. Earth
3. asteroid belt
4. Neptune
1. asteroid belt
2. Saturn
3. Pluto
4. Uranus
1. Pluto
2. Uranus
3. Neptune
4. asteroid belt
1. asteroid belt
2. Earth's moon
3. Venus
4. Mercury
Which of the following correctly describes the relationship between astronomical bodies in outer space?
Mars is larger than Earth.
The Milky Way is much larger than our Solar System.
The Moon is further away from the Sun than the asteroid belt.
The time it takes Earth to revolve around the Sun is longer than it takes Marts to revolve around the sun.
The brightness of a star as seen from Earth is its apparent magnitude. How is apparent magnitude different
from absolute magnitude?
Apparent magnitude depends on the size of a star; absolute magnitude does not.
Apparent magnitude depends on the temperature of a star; absolute magnitude does not.
Apparent magnitude depends on the distance of a star from Earth; absolute magnitude does not.
Apparent magnitude depends on the color of a star; absolute magnitude does not.
The graph below shows the relationship between absolute magnitude and color in stars.
Which one of these conclusions can be drawn based on the graph?
Absolute magnitude is not related to the color of a star.
Blue stars are farther from Earth than red stars.
Blue stars are generally emit more light than red stars.
A blue star will appear brighter from Earth’s surface than a red star.
Which physical property of a star is an indicator of its temperature?
mass
color
brightness
distance from Earth
The planets are often placed into two groups. Mercury, Venus, Earth, and Mars are one group. Jupiter, Saturn, Uranus, and Neptune are another group. Which characteristic was used to group the planets this way?
distance from the Sun
ability to sustain life
direction they revolve and rotate
number of moons revolving around them
The chart below lists several planets and their distances from the Sun in astronomical units (AU).
Which list correctly orders the length of each planet's year, from shortest to longest?
Earth, Mercury, Saturn, Neptune
Mercury, Earth, Saturn, Neptune
Earth, Mercury, Neptune, Saturn
Mercury, Earth, Neptune, Saturn
Which difference between Earth and the Moon explains why an astronaut is easily able to hop on the Moon?
The Moon's rotation on its axis is shorter than Earth's rotation on its axis.
The Moon's orbit around Earth is shorter than Earth's orbit around the Sun.
The force of gravity on the Moon is lower than the force of gravity on Earth.
The force of gravity from the Sun sometimes briefly lifted the astronauts off the Moon's surface.
The drawing shows Earth's revolution around the Sun.
Based on the drawing, what season are students in Florida experiencing when Earth is at position 1?
Fall
Spring
Summer
Winter
Ping’s class is studying the Sun/Moon/Earth system. He studies the diagram of the sun, moon, and Earth shown below.
What event is shown in the diagram?
solar eclipse
lunar eclipse
full moon
neap tide
The diagram shows the alignment of the sun, the moon, and Earth.
Which of the following best explains why HIGH TIDES are happening at locations 1 and 3?
the moon's gravitational pull on Earth
Earth's tilt and orbit around the sun
the sun's gravitational pull on Earth
radiation from the sun
Chenia drew the diagram below to show that Earth’s axis of rotation is not
perpendicular, but tilted. Which of the following does the tilt of the axis of rotation best explain?
why Earth has tides
how long an Earth day is
how long an Earth year is
why Earth has seasons
Julia and her father are planning a fishing trip. They think that fishing is better during the incoming tide. Which of the following diagrams shows the arrangement of the Sun, the Moon, and Earth that will result in the largest change in tides so that Julie and her dad have the best fishing experience?
Look at the diagram of the phases of the moon. What numbered position represents the first quarter moon?
1
2
3
4
These three images represent the particle arrangement in ice, water, and steam.
Which of the following correctly identifies the states of matter?
A: steam, B: water, C: ice
A: water, B: steam, C: ice
A: steam, B: ice, C: water
A: ice, B: water, C: steam
Joan is finding the density of four containers of different sizes using a metric balance and large beaker. She has found that each of the four containers has a mass of 20.0 grams (g). The chart below shows the mass and volume of each of the containers (cm3 = cubic centimeters).
Which container most likely contains the least dense material? Be aware that the density
equation is d = m/ v, with d being density, m being mass, and v being volume.
Container 1
Container 2
Container 3
Container 4
A student compares the mass and density of two objects. Object A and Object B both have the same mass. However, Object A has more density than Object B.
How can two objects with the same mass have a different density?
The two objects have a different area.
The two objects have a different shape.
The two objects have a different weight.
The two objects have a different volume.
Rachel is looking at the periodic table. She notices an atom has 4 negatively charged particles outside the nucleus. What does this indicate about the atom?
It is very unstable.
It contains 4 neutrons.
It contains four electrons.
It is a negatively charged atom.
Audra is looking at a diagram of an atom. Which particle(s) does she see inside the nucleus?
electrons only
protons only
electrons and protons
protons and neutrons
The illustration below lists the pH of various substances.
Which of the substances below is the closest to neutral pH?
ammonia
milk of magnesia
milk
vinegar
Which is the most correct explanation of a physical change that has occurred?
crushing an ice cube, because the chemical structure of the ice cube is changed
dicing potatoes, because the molecules are separated but remain the same substance
gasoline burning, because it forms water vapor and carbon dioxide
fireworks exploding, because energy is released as light and heat
Steve fills a jar with water and adds Epsom salts and ammonia. After five minutes, he observes that white particles have formed and settled at the bottom of the jar. Steve is unable to change these particles back to any of the three original substances by heating or stirring the solution. He isolates the white particles and finds that they have properties that are very different from any of the three starting materials.
Which statement best explains Steve's observation?
A chemical change occurred because a new substance formed.
A chemical change occurred because a solid substance formed.
A physical change occurred because no color change was observed.
A physical change occurred because stirring did not change the solution.
Will made a cup of hot tea and placed it on the table. A few minutes later, he picked up the cup and touched the warm table where the cup had been sitting. He put the cup back in the same place and left the kitchen. When he returned a few hours later, he noticed the table and the cup felt the same temperature as each other. Which of these statements best describes the heat flow between the cup and the table?
The heat flowed from the table to the cup through the process of convection.
The heat flowed from the table to the cup through the process of conduction.
The heat flowed from the cup to the table through the process of conduction.
The heat flowed from the cup to the table through the process of convection.
The Sun and Earth each have a gravitational pull on each other. How would that gravitational force be affected if Earth were much farther from the Sun?
The gravitational force would increase.
The gravitational force would decrease.
The gravitational force would be unchanged.
The gravitational force would cause higher tides.
The diagram shows how one way that material can be organized inside of a living thing.
Which of these terms best fits into the space labeled 'X' in the diagram?
atoms
tissues
organisms
organ systems
Ava has a list of organisms she is studying in science class. Her organisms are bacteria, pine trees, and elephants. Which organisms based on cell theory are made of cells.
Pine trees because only plants are made of cells.
Elephants because only animals are made of cells.
Bacteria because only microscopic organisms are made of cells.
Bacteria, pine trees, and elephants because all organisms are made of cells.
Many cellular processes are performed by cells. A typical cell and a common process is shown in the diagram below.
Which of the following is the best reason this cell is going through the process shown?
to reproduce another cell
to compete with another cell
to maintain homeostasis of the cell
to provide protection for the cell from the environment
Cells are able to maintain homeostasis by keeping the perfect balance of water and nutrients inside of them.
Which cell part regulates the materials that leave or enter the cell to maintain this balance?
the nucleus
the cell membrane
the chloroplast
the endoplasmic reticulum
Both the cell membrane and the cell wall act to protect the organelles within a cell. Which of the following best describes how the cell membrane is different from the cell wall?
The cell membrane is made of a tough cellulose fiber, whereas the cell wall is made of a flexible glycogen fiber.
The cell membrane only controls what crosses into the cell, whereas the cell wall only maintains a cell's rigidity.
The cell membrane is a single-layered membrane, whereas the cell wall is a double-layered membrane.
The cell wall is only found in plant cells, whereas the cell membrane is found in plant and animal cells.
Which organelle is needed for plants to make energy?
Vacuole
Cytoplasm
Mitochondrion
Cell Membrane
What type of infectious disease is not living, and can be transmitted through air? A common cold and influenza are examples of this type of infectious disease.
Bacteria
Virus
Parasite
Fungi
Which of the following do viruses and bacteria have in common?
They both can reproduce without the help of a host cell.
Neither of them uses energy to carry out functions.
Neither of them responds to stimuli.
They both have genetic material.
A teacher uses the diagram below to help him explain heredity to a group of students.
Which of these combinations identifies the appropriate labels in the order as shown in the diagram (1, 2, 3)?
chromosome, DNA, gene
chromosome, gene, DNA
DNA, chromosome, gene
DNA, gene, chromosome
The digestive and circulatory systems interact with each other to help maintain homeostasis in the human body. Which pair of actions describe how these two systems work together to maintain homeostasis?
taking in oxygen and transporting it to all the cells
providing nutrients and transporting them to the cells
moving nutrients and fighting infections in the body
removing wastes and excreting them out of the body
In pea plants, purple flowers (P) are dominant to white flowers (p).
If one parent has a genotype of Pp and one parent has a genotype of pp, what is the probability of the offspring having purple flowers?
0 percent
50 percent
75 percent
100 percent
Rabbits born with the recessive trait of albinism lack pigment. The pedigree chart below shows the inheritance pattern of albinism in a certain family of rabbits.
What is missing in the pedigree for the first generation?
Rabbit 6 should have shading.
All rabbits of the first generation should be shaded.
All rabbits in the first generation should be shown as normal.
Florida panthers can have straight tails (S) or curly tails (s). What is the probability that two heterozygous panthers (both Ss) will have offspring with curly tails?
25%
50%
75%
100%
Which statement best describes the result of meiosis?
The daughter cells have half the number of chromosomes.
The daughter cells have twice the number of chromosomes.
The daughter cells have the same number of chromosomes.
The daughter cells have four times the number of chromosomes.
A cell is about to undergo mitosis. Which of these statements describes the resulting daughter cells?
One daughter cell will have more chromosomes than the other daughter cell.
Both daughter cells will be genetically identical to the parent cell, and each will have the same number of chromosomes.
The daughter cells will be genetically identical to each other but will have a different number of chromosomes from the parent.
Each daughter cell will have a new arrangement of chromosomes and characteristics, and each will be different from each other and the parent cell.
One living plant leaf, still attached to the plant, is placed into a cup and covered with water. A light source is placed above the cup shining into the cup of water so that the leaf receives the light. In moments, bubbles appear at the surface of the plant leaf.
Which statement explains what causes the bubbles to appear?
Photosynthesis is occurring and bubbles of carbon dioxide gas are being released by the surrounding area and absorbed into the plant leaf.
Photosynthesis is occurring and bubbles of carbon dioxide gas are being released by the leaf into the surrounding area.
Photosynthesis is occurring and bubbles of oxygen gas are being released into the surrounding area.
Photosynthesis is occurring and bubbles of air are entering the water from the area around the plant.
Which of the following pairs are products of photosynthesis?
sugar and oxygen
chlorophyll and protein
light energy and nitrogen
water and carbon dioxide
Which of the following is the correct equation for cellular respiration?
energy + water → carbon dioxide + water + glucose
glucose + carbon dioxide → oxygen + water + energy
glucose + oxygen → carbon dioxide + water + energy
oxygen + water → carbon dioxide + energy + glucose
Organisms have specialized structures for different functions. Humans, for example, have an acid-filled stomach that helps break down swallowed food. Cells also have specialized structures for specific functions.
What cellular structure is shown in the diagram and what does it do?
chloroplast; cellular respiration
mitchondrion; photosynthesis
chloroplast; photosynthesis
mitochondrion; cellular respiration
All living organisms contain carbon. As organisms grow, they require large quantities of carbon to carry out life processes and make new cells. Where is the source of most of Earth's available carbon?
Carbon is constantly recycled from dead organisms back into the environment.
New carbon atoms are constantly being created by the process of photosynthesis.
Carbon atoms are constantly transferred from the Sun to Earth along with sunlight.
Carbon is constantly transported from the mantle to the crust by volcanic eruptions.
Marc wants to use the picture below to show how carbon cycles between organisms and the environment.
Which parts of the carbon cycle is shown in the illustration?
cellular respiration and decomposition
combustion and decomposition
decomposition and photosynthesis
photosynthesis and cellular respiration
Which statement about the carbon cycle is most true?
Energy is destroyed when organic matter decays.
The total mass of carbon on Earth is always increasing.
Carbon is lost from the cycle when it enters the atmosphere.
Carbon changes form, but the total amount on Earth remains the same.
What are the primary producers in this food web?
sun and water
worms and crustaceans
shorebirds and wading birds
sediment algae and floating algae
A food web shows how energy moves from one organism to another in an ecosystem. Students in a life science class created a diagram demonstrating a food web.
Based on the food web, which of these organisms receives some of its energy directly from a primary consumer?
Caterpillar
Clover
Hawk
Rabbit
Barnacles are arthropods closely related to crabs and lobsters. Barnacles are usually found on rocky surfaces, but there are some species that attach themselves to turtles and whales. The barnacles feed on nutrient–rich waters as the turtles and whales travel. The whales and turtles do not benefit or get hurt from the barnacles.
Which type of relationship do the barnacles have with the whales and turtles?
competition
predation
mutualism
commensalism
Jane went for a walk on the farm. First, she saw a mosquito land on her arm and bite her. Second, she saw a hawk capture a mouse. Last, she noticed a bird riding on the back of a cow and eating the bugs off it. What is the order of the relationships Jane saw at the farm?
competition, predation, parasitism
parasitism, competition, mutualism
parasitism, predation, mutualism
predation, competition, parasitism
In 1990, there were 2,000 deer living on a remote island. The island is roughly 520 square kilometers in size. The island managers decided to introduce wolves as a natural predator. In 1991, 10 wolves were flown onto the island. The table shows the changes in both the deer and wolf populations for the years 1991 to 2000.
disease
shelter
food
water
The Florida Everglades is habitat for many animals including deer, alligators, squirrels and panthers and for various types of plants and trees. A large wildfire sweeps through the habitat and kills most of the plants and trees. Which description is most likely a result after a wildfire?
Some plants will no longer need a water source.
Some animals will move to other locations to find food.
Some plants will give off more carbon dioxide into the air.
Some animals will become sick because more diseases are present.
