2025 STAAR Prep 8th Science

The equation for photosynthesis is shown.

Which statement about the equation BEST identifies evidence that mass is conserved during photosynthesis?

• The number of molecules in the reactants is equal to the number of molecules in the products.

• The number of molecules in the reactants is equal to the number of carbon atoms in the products.

• The number of the states of matter in the reactants is equal to the number of states of matter in the products.

• The number of atoms for each element in the reactants is equal to the number of atoms for each element in the products.

Tags

NGSS.MS-LS1-6

NGSS.MS-PS1-5

Which statement BEST describes a component of cell theory?

• All cells from from molecules.

• All cells come from pre-existing cells.

• All cells create genetically identical cells.

• All cells reproduce from simpler cells.

Which statement correctly describes one of the two gases?

• The chemical formula for gas X is NO & is made of nitrogen & oxygen

• The chemical formula for gas Y is N₂O & is made of nitrogen & oxygen

• The chemical formula for gas X is N₂O₂ & is made of neon & osmium

• The chemical formula for gas Y is N₃O₃ & is made of neon & osmium

Tags

NGSS.MS-PS1-1

Using the table shown, which table column of information would BEST be used for knowing the chemical formula of NO₂ ?

• Number of atoms per molecule

• Types of elements

• Volume of sample

• Molecular composition

Tags

NGSS.MS-PS1-1

Students measure the mass of two different substances in Test Tubes A and B. Both substances are then added to Test Tube C, and a reaction occurs. The students observe bubbles in the resulting solution. After the reaction is complete, the students measure the mass of the substance in Test Tube C.

• Less than 35 grams because gases have less mass than solids

• Less than 35 grams because gases escaped into the atmosphere during the chemical reaction

• Exactly 35 grams because mass is conserved when chemical reactions produce gases

• Exactly 35 grams because chemical reactions cause substances to change phases into a gas

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which factor contributes MOST to the formation of a hurricane?

• High water temperatures

• High water density

• High water oxygen levels

• High water volume

Tags

NGSS.MS-ESS2-6

Many types of plants stand upright when they are healthy and have received plenty of water.

During an extended drought, however, plants often do not have access to enough water. In an arid environment or in an area with frequent droughts, only plants well adapted to the dry conditions will survive long enough to produce seeds. These seeds then sprout and grow into more drought-resistant plants.

Which pair of cell parts are MOST responsible for helping plants stand upright after receiving plenty of water?

• Nucleus and ribosome

• Cell wall & vacuole

• Vacuole & mitochondria

• Mitochondria & chloroplast

Tags

NGSS.MS-LS1-2

Match the cell organelle with the correct function of that cell organelle.

• photosynthesis

• cell wall

• passage of materials in/out of cell

• chloroplast

• cell respiration: convert glucose->ATP

• vacuole

• cell protection & structure/rigidity

• cell membrane

• storage of waste/water

• mitochondria

Tags

NGSS.MS-LS1-2

Which cell part is most directly involved in the process that allows plants to adapt to drought conditions?

• Cell membrane, because it can become more efficient to create drought resistance

• Cell nucleus, because it contains information that determines the drought resistant traits passed to next generation

• Cell wall, because it adjusts to holding more water, so the next generation of plants can survive droughts

• Cell vacuole, because it expands to hold more water making future generations more drought resistant

Tags

NGSS.MS-LS1-2

A student graphs the motion of a toy car moving in a straight line over a 10‑second time period.

Which statement BEST describes the motion of the car?

• The car moved at a speed of 5 meters per second for the first 5 seconds, then went at a slower speed for the next 5 seconds.

• The car moved at a speed of 5 meters per second for the first 5 seconds, then went at a faster speed for the next 5 seconds.

• The car moved at a speed of 1 meter per second for the first 5 seconds, then went at a slower speed for the next 5 seconds.

• The car moved at a speed of 1 meter per second for the first 5 seconds, then went at a faster speed for the next 5 seconds.

Tags

NGSS.MS-PS3-1