Unit 3 - Grade 8

Which of the following describes molecular movement during active transport?

• high concentration --> low concentration; uses ATP
• high concentration --> low concentration; does not use ATP
• low concentration --> high concentration; uses ATP
• low concentration --> high concentration; does not use ATP

Which organelle is responsible for keeping concentrations of molecules balanced within a cell?

• ribosome
• endoplasmic reticulum
• cell membrane
• chloroplast

Carbon and oxygen are kept at constant levels within the atmosphere due to

• digestion and synthesis
• respiration and synthesis
• respiration and photosynthesis
• photosynthesis and digestion

Molecule A moves through the membrane while molecule B does not. Which of the following is a valid conclusion?

• Molecule A is bigger than molecule B.
• Molecule A is smaller than molecule B.
• Molecule A must be digested before it can diffuse.
• Molecules A and B are the same size.

If cell A has more mitochondria than cell B, it can be inferred that cell A

• does not require energy
• has energy requirements equal to cell B
• requires less energy than cell B
• requires more energy than cell B

Which organelle controls the movement of molecules into and out of the cell?

• nucleus
• cell membrane
• vacuole
• chloroplast

Which of the following describe photosynthesis?

• glucose and oxygen combine to form carbon dioxide and water
• oxygen and carbon dioxide combine to form glucose and water
• carbon dioxide and water combine to form glucose and oxygen
• glucose and water combine to form oxygen and carbon dioxide

What two substance leave a mitochondria after the process of cellular respiration?

• carbon dioxide and sugar
• oxygen and ATP
• carbon dioxide and ATP
• oxygen and sugar

In order to be used during cellular respiration, starch must be 

• absorbed through the skin
• digested into fat and water
• digested into glucose
• converted into carbon dioxide and ATP

Which of the following pairs the polymer (P) with the correct monomer (M)?

• P: starch - M: amino acid
• P: sugar - M: starch
• P: protein - M: amino acid
• P: amino acid - M: sugar