Science 8 PSSA Item Sampler 2022

The germ theory of disease states that diseases are caused by microorganisms . These organisms are too small to be seen by a human eye unless they are magnified by a microscope . The spread of disease results from these organisms entering a host. Which statement best explains how this theory is different from an opinion?

• The germ theory of disease was made by scientists, but opinions are made by nonscientists

• The germ theory of disease does not change, but opinions can change when new discoveries are made

• The germ theory of disease is a group of ideas that scientists believe are true, but only nonscientists believe opinions are true

• The germ theory of disease is supported by evidence collected by many scientists over time, but opinions can be made without evidence

Which statement is an inference that is best supported by the data shown in the chart?

• The students’ heart rates increase with exercise

• Student X’s heart rate is higher after exercise than at rest

• Student Y’s heart rate is higher at rest than student Z’s at rest

• The students’ heart rates during exercise are greater than after exercise

A fossil collector found crinoid fossils . The collector did some research and read the information shown . What can the collector best infer about the area where the fossil was found

• The area may once have been the site of an ocean

• The rocks in the area most likely formed in the last 1,000 years

• The area was most likely also a habitat for sea stars and sea urchins

• The rocks in the area may have been moved from a different location

Tags

NGSS.MS-ESS2-3

NGSS.MS-LS4-1

A student follows a recipe using the ingredients shown to make lemonade . Which statement describes a relationship between ingredients in this recipe?

• There should be 20 cups of water for every 10 cups of sugar .

• There should be 5 cups of lemon juice for every cup of sugar

• There should be 4 cups of water for every cup of lemon juice .

• There should be 1 cup of sugar for every 5 cups of lemon juice

Based on trophic levels, which classification of organisms is one degree of order higher than herbivores?

• primary producers

• tertiary consumers

• primary consumers

• secondary consumer

The diagram shows flight paths between several cities . What does this system best represent?

• a positive feedback loop

• a hub-and-spoke system

• a negative feedback loop

• a symmetrical truss system

Some organisms, such as mammals, have closed blood circulation systems . In mammals, blood is moved throughout the body inside blood vessels . Other organisms, such as insects, have open blood circulation systems . In insects, blood is moved to large spaces inside the body, where it comes into contact with tissue . Despite working in different ways, these blood circulation systems have similar purposes . Which statement correctly describes one of the purposes they share?

• Both systems move materials throughout the organism’s body

• Both systems remove harmful waste products from the organism’s body

• Both systems transmit signals from the organism’s muscles to its nervous system

• Both systems change food into useful nutrients and energy for the organism’s cells

Which biome is best described by these characteristics?

• desert

• tundra

• tropical forest

• deciduous forest

Fires during dry seasons in the savanna (grassland) biome maintain community health . Some consumer organisms, like insects and mice, are killed by these fires, while other consumers, like birds, eat organisms affected by the fires . How does this pattern best illustrate the effect of diversity?

• It reduces the frequency of negative environmental events

• It allows organisms to adapt more rapidly to changing local conditions

• It helps maintain overall ecosystem health and efficiency of resource use

• It helps maintain overall ecosystem health and efficiency of resource use

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

NGSS.MS-LS2-5

Which statement correctly describes the reactants in the reaction shown?

• CH4 and O2 are the reactants because they combine to form new compounds

• CH4 and O2 are the reactants because they have the highest number of atoms

• CO2 and H2O are the reactants because they are formed following an initial reaction

• CO2 and H2O are the reactants because they both exist as gases at room temperature

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5