Keystone Review Energy and Matter (E, G, J)

What is the primary source of energy used in photosynthesis?

• Water

• Sunlight

• Carbon dioxide

• Oxygen

Answer explanation

The primary source of energy in photosynthesis is sunlight. Plants capture sunlight to convert carbon dioxide and water into glucose and oxygen, making sunlight essential for this process.

Tags

NGSS.MS-LS1-6

What gas is released as a byproduct of photosynthesis?

• Carbon dioxide

• Nitrogen

• Oxygen

• Hydrogen

Answer explanation

During photosynthesis, plants convert carbon dioxide and water into glucose and oxygen. The oxygen produced is released as a byproduct, making it the correct answer.

Tags

NGSS.MS-LS1-6

Which of the following is the correct overall chemical equation for cellular respiration?

Answer explanation

The correct equation for cellular respiration shows glucose (C6H12O6) and oxygen (O2) being converted into carbon dioxide (CO2), water (H2O), and energy. This matches the choice: C6H12O6 + 6O2 → 6CO2 + 6H2O + energy.

Tags

NGSS.MS-LS1-7

In cellular respiration, what molecule is broken down to release energy?

• Oxygen

• Water

• Glucose

• Carbon dioxide

Answer explanation

In cellular respiration, glucose is the primary molecule broken down to release energy. It undergoes glycolysis and the Krebs cycle, ultimately producing ATP, the energy currency of the cell.

Tags

NGSS.MS-LS1-7

Which of the following best describes aerobic respiration?

• A process that occurs without oxygen

• A process that requires oxygen to break down food molecules

• A process that only happens in plants

• A process that produces glucose from sunlight

Answer explanation

Aerobic respiration is a process that requires oxygen to break down food molecules, producing energy. The other options describe anaerobic processes or photosynthesis, which do not accurately define aerobic respiration.

What term describes the process by which matter moves through living organisms and the environment in a repeated cycle?

• Energy flow

• Cycling of matter

• Photosynthesis

• Fermentation

Answer explanation

The term 'cycling of matter' refers to the continuous movement of matter through living organisms and the environment, highlighting how elements are reused in ecosystems, unlike energy flow which is a one-way transfer.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

In the model of photosynthesis, which molecule stores the chemical energy produced from light energy?

Answer explanation

In photosynthesis, plants convert light energy into chemical energy, primarily stored in glucose (C6H12O6). Oxygen (O2) is a byproduct, while water (H2O) and carbon dioxide (CO2) are reactants, not energy storage molecules.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

A student draws a model of photosynthesis. Which of the following correctly shows the transformation of energy in photosynthesis?

• Chemical energy is converted into light energy

• Thermal energy is converted into chemical energy

• Light energy is converted into stored chemical energy in glucose

• Mechanical energy is converted into light energy

Answer explanation

In photosynthesis, plants convert light energy from the sun into stored chemical energy in glucose. This process is essential for producing food, making the correct choice 'Light energy is converted into stored chemical energy in glucose'.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3

During cellular respiration, when the bonds in glucose and oxygen molecules are broken, what happens to the energy that is released?

• It is lost entirely as heat

• It is transferred to new compounds such as ATP, which cells can use

• It is stored back into glucose molecules

• It is converted directly into light energy

Answer explanation

During cellular respiration, the energy released from breaking bonds in glucose and oxygen is primarily transferred to ATP. This ATP serves as an energy currency for cells, enabling them to perform various functions.

Tags

NGSS.MS-LS1-7

A student compares photosynthesis and cellular respiration. Which statement correctly describes how these two processes are related?

• Both processes produce oxygen and consume carbon dioxide

• Photosynthesis stores energy in glucose, and cellular respiration releases that energy

• Cellular respiration produces glucose, and photosynthesis breaks it down

• Both processes require sunlight to function

Answer explanation

Photosynthesis converts sunlight into chemical energy, storing it in glucose. Cellular respiration then breaks down glucose to release that stored energy, highlighting their interdependent roles in energy transformation.

Tags

NGSS.HS-LS2-3

NGSS.HS-LS2-5