CAASPP Grade 8 Science

A water bottle is often designed with a vacuum layer to provide insulation as shown. A foam insulating cover can be added.

Several water bottles with a vacuum layer design are described in the table. Each bottle is the same size and has a steel outer lining. The inner lining can be made of different materials.

Students are asked to make a claim about which design will meet two criteria. The bottle must be break-resistant and must keep the water hot for the longest time. They are also asked to provide a supporting statement for their claim.

Which student claim and supporting statement are about the design that best meets the two criteria?

A paramecium is a single-celled freshwater organism that can be observed using a microscope. A typical paramecium is shown.

A scientist started a paramecium culture in the laboratory to study population growth. A model of population growth for the paramecium culture is shown in the graph. The carrying capacity is the number of individuals that the environment has enough resources to support.

Explain why the paramecium population growth is rapid at the part labeled A and why the population growth rate is slower at the part labeled B, where the population is at carrying capacity. Enter your answer in the space provided.

A tsunami is a series of waves, and it is usually caused by an earthquake. A tsunami can only be predicted after an earthquake has already occurred. Most tsunamis are caused by earthquakes with magnitudes over 7.0 that occur under the ocean or near coastlines. These earthquakes are also less than 100 kilometers (km) below Earth's surface. This table summarizes the magnitude, location, and depth of four earthquakes.

Based on this information, which earthquake has the greatest likelihood of causing a tsunami to develop?

A student wants to show a friend that a magnetic field exists in the region around a permanent magnet.

For each demonstration listed in the table, select a circle to indicate whether the student can use the demonstration to show that a field exists in a region around a magnet.

A student learning about heat transfer makes the claim shown.

The student proposes to test the claim in the laboratory by using metal rods of iron (Fe), copper (Cu), and aluminum (Al). In addition to the metal rods, which pieces of equipment would be useful for investigating the claim?

DNA contains a code for synthesizing proteins. Three nucleotides in a row code for a particular amino acid. There are four nucleotides in DNA, which are abbreviated as A, T, C, G. The amino acids are joined to form a protein.

Genetic mutations can occur in the DNA of individuals. Some mutations are harmful, some have no effect, and some might be beneficial to the organism. The table shows the nucleotide sequence of DNA that codes for a protein in one individual and the nucleotide sequence of the same segment of DNA in an individual with a mutation.

Which statement describes the most likely impact of the mutation in the mutated sequence?

In June 1991, Mount Pinatubo in the Phillipines erupted. The eruption released large amounts of gases, such as sulfur dioxide, water vapor, and carbon dioxide, into the atmosphere. Sulfur dioxide reacted with water to form aerosol particles, and an aerosol cloud formed that covered a a large portion of Earth.

Students want to determine what effect the eruption had on global climate. Which question should the students investigate to best determine the effect?

During a La Niña event, the temperature of the Pacific Ocean near Central America becomes cooler than normal. As a result, more clouds form, and this can block sunlight from reaching plants in Central American forests. A researcher studying the effects of La Niña measured the amount of carbon dioxide (CO2) uptake by tropical plants under different light intensities. The data are shown in the graph.

Predict how a La Niña event affects the rate of photosynthesis by plants in the tropical forests of Central America. Provide evidence from the graph to support your prediction. Enter your answer in the space provided.

A biologist wanted to study how certain plant structures, such as colored flowers, might affect how often the plants are pollinated during the day. For one hour on a sunny summer day, the biologist observed bee, butterfly, hummingbird, and beetle pollinators of a population of plants with equal numbers of purple, white, and pink flowers. Based on the data collected and shown in the table, the biologist made the claim that plants with purple flowers in this population attract more pollinators than do plants with flowers of other colors.

Which evidence could be used to challenge the biologist's claim that purple flowers in the population of plants attract more pollinators than other flower colors do?

A scientist measures the amplitude and wavelength of waves in the ocean. The scientist also calculates the amount of energy contained in one square meter of water for each wave. The data and calculations for four different waves are shown in the table.

Which wave characteristics, if any, does the energy in the wave depend on?

Six stones of different shapes and masses are lifted to various heights above Earth's surface, as shown in the table. The table also shows the gravitational potential energy of each stone-Earth system, which is defined as zero when a stone is resting on the ground.

Select the circles to indicate what happens to the gravitational potential energy of a stone-Earth system when each indicated change to the system is made.

The diagram shows a cross section of layers of sedimentary rocks. The types of fossils in each layer are shown.

Based on the information in the cross section, select the three statements that are most likely correct.

The embryos of two vertebrate animals at the same stage of development are shown in the figure.

Which best explains why the embryos are similar in appearance, yet the adults look different.

Plastic A is commonly used to make disposable water bottles. Plastic B can also be used to make these bottles. Information about Plastic A and Plastic B is given in the table.

Based on the information in the table, explain two ways how using Plastic B instead of Plastic A to make disposable water bottles can help conserve natural resources. Enter your answer in the box provided.

A certain species of flowering plant has populations that grow near sea level and populations that grow at high elevations. Scientists collected seeds from the plants growing at different elevations and plated the seeds at a high elevation and near sea level. The heights of the plants grown from the seeds are shown in the table.

Based on the data, which two statements about the height of this species of plant are most likely correct?

A student creates the model shown of the water cycle for a class presentation. The student's main goal is to help the class understand how living organisms assist in the movement of water through the system.

Based on the model, what should the student say about the role of living organisms in the water cycle?

Baker's yeast (Saccharomyces cerevisiae) is a fungus that has been used as a model organism for research on reproduction, because it can reproduce both sexually and asexually.

This table helps explain the differences in genetic variation that results from sexual and asexual reproduction in organisms such as baker's yeast. Select one circle in each row to indicate whether each statement describes a feature of sexual reproduction, asexual reproduction, or both.

California has experienced many significant periods of drought as a result of both environmental factors and human activities. Conservation of groundwater has therefore become very important, even when California receives a lot of rain. Proposed ways of conserving groundwater include reducing water use, reusing water, and finding other sources of water.

For each conservation practice listed in the table, select how the practice most directly conserves groundwater. Select one circle per row.

Students are asked to develop models of the solar system. One student suggests that a ball circling a pole may be used to model the Sun, Earth, and the force of gravity. the model is shown in the diagram.

Which statement best describes how the model represents the Sun and Earth?

Part B

Water in lakes and streams may contain particles of soil and decaying plants that cloud the water. Which method will most likely be effective at making the water clear when removing pathogens?

Part A

Which two characteristics should the students consider when addressing the time the oven takes to heat food?

Which statement best explains why two dark-brown squirrels could have kits that are gray or black?

Based on the data in the graph, which two types of additional information would best help to interpret the data in the graph?

Explain how the pattern in the graph supports the claim that the genetic mutation for black fur was at some times harmful and at other times helpful to survival. Enter your answer in the box provided.

Which two statements correctly describe the relative potential energy at various points on the track?

If the second hill wasn't lower than the first hill, the roller coaster train would

Three possible observations are proposed to test these claims, as shown in the chart. Indicate if each observation would support Claim 1 or Claim 2 by selecting the circles in the chart.

To save money, engineers want to replace the train with a new train that has half the mass of the original train at 1,650 kg when empty. The new train will have a velocity of 28 m/s at the bottom of the first hill.

• Based on this information, respond to the following questions:

• How will the kinetic energy of the new train compare to the kinetic energy of the original train when both are empty?

• What property of the new train causes the difference in kinetic energy?

Enter your answer in the space provided.

The students want to answer this question:

Which question should the students answer as part of their research?

Use the graph, beaker setups, and student claims to answer these two questions.

• Which student claim would be best supported by the graph?

• Which two beakers should be compared to support the student claim?

Enter your answer in the space provided.

Which two sources of CO₂ data would provide evidence to support the claim of Student 2?