F23 POB Exam 2

The cell theory states...

A. all organisms are composed of only one cell

B. organelles are the basic living unit of structure and function of organisms

C. all cells come only from other cells

D. all organisms are composed of only one cell AND organelles are the basic living unit of structure and function of organisms

C. all cells come only from other cells

According to cell theory...

A. all organisms are composed of tissues

B. the smallest unit of life is a nucleus

C. a multicellular organism is composed of many cells

D. new cells arise only from preexisting cells.

D. new cells arise only from preexisting cells

Proteins are processed and modified in the interior of the

A. mitochondria

B. nucleus

C. chloroplasts

D. rough endoplasmic reticulum

D. rough endoplasmic reticulum

Which cellular structure is responsible for packaging materials with the cell?

A. mitochondria

B. chloroplasts

C. Golgi apparatus

D. lysosomes

C. Golgi apparatus

In order to digest materials within a cell, the material to be digested must fuse with

A. a lysosome

B. the Golgi apparatus

C. a secretory vesicle

D. smooth endoplasmic reticulum

A. a lysosome

This organelle absorbs and coverts oxygen while releasing CO2 and water.

A. lysosomes

B. Golgi apparatus

C. mitochondria

D. chloroplasts

E. endoplasmic reticulum

C. mitochondria

Cellular respiration is best associated with the

A. Golgi apparatus

B. ribosome

C. mitochondrion

D. chloroplast

E. microtubule

C. mitochondrion

Which of the following is NOT evidence supporting the endosymbiotic theory?

A. the vacuoles can "come and go" across the plasma membrane

B. mitochondria and chloroplasts have their own DNA

C. mitochondria and chloroplasts are nearly identical to some free-living prokaryotes

D. mitochondria and chloroplasts divide by splitting

A. the vacuoles can "come and go" across the plasma membrane

This is a multiple answer question. Choose all that are correct.

The nucleus

A. is found in eukaryotes

B. has a single-layered membrane

C. stores genetic material

D. is the only organelle containing DNA

E. contains chromatin

F. can live independently of a cell

A. is found in eukaryotes

C. stores genetic material

E. contains chromatin

This is a multiple answer question. Choose all that are correct.

The nucleus

A. is found in bacteria

B. has a double membrane

C. stores genetic material

D. is the only organelle containing DNA

E. contains chromatin

F. can live independently of a cell

B. has a double membrane

C. stores genetic material

E. contains chromatin

This is a multiple answer question. Choose all that are correct.

This structure has hereditary material inside it.

A. mitochondrion

B. nucleus

C. chloroplast

D. ribosome

E. flagellum/cilium

F. lysosome

A. mitochondrion

B. nucleus

C. chloroplast

This is a multiple answer question. Choose all that are correct.

Which of the following would be found as part of all cells?

A. DNA

B. plasma membrane

C. ribosomes

D. mitochondria

E. chloroplasts

F. fimbriae

A. DNA

B. plasma membrane

C. ribosomes

A flagellum is able to bend due to being made of __________ that can bend by sliding past one another under the influence of the motor protein __________.

A. microtubules/dynein

B. actin filaments/myosin

C. phospholipids/thylakoids

D. intermediate filaments/keratin

A. microtubules/dynein

Place the stages of the endosymbiotic theory in the proper order.

1. A prokaryotic cell evolves the ability to fold in, invaginate, its cell plasma membrane.

2. The DNA is isolated from the rest of the cell becoming a nucleus.

3. The eukaryotic cell envelopes an aerobic bacterium that evolves into a the mitochondria.

4. The eukaryotic cell that has mitochondria envelops a green photosynthetic bacterium, a cyanobacterium, that evolves into chloroplasts.

The innermost membrane of the chloroplast is referred to as the...

A. thylakoid membrane

B. inner membrane

C. cristae

D. stroma

A. thylakoid membrane

Imagine starting in the innermost space of the chloroplast and moving outward until leaving the chloroplast and entering the cytoplast. What is the starting point and proper order of things you would move through?

A. thylakoid space - thylakoid membrane - stroma - inner membrane - outer membrane

B. stroma - inner membrane - thylakoid space - thylakoid membrane - outer membrane

C. stroma - inner membrane - thylakoid membrane - thylakoid space - outer membrane

D. matrix - inner membrane - intermemebrane space - outer membrane

A. thylakoid space - thylakoid membrane - stroma - inner membrane - outer membrane

Which of the following is NOT a function of the cell membrane?

A. It provides mechanical strength to the cell.

B. It gives shape to the cell.

C. It regulates passage of molecules into and out of the cell.

D. It is largely responsible for cellular homeostasis.

E. It serves as a site for protein synthesis.

E. It serves as a site for protein synthesis.

According to the fluid-mosaic model of membrane structure,

A. proteins make up the bulk of the membrane

B. only lipids are found in the membrane

C. cholesterol is the main constituent of the membrane

D. proteins float inside or within the phospholipid bilayer

D. proteins float inside or within the phospholipid bilayer

The plasma membrane is composed of

A. proteins and microtubules

B. phospholipids and actin filaments

C. phospholipids and microtubules

D. phospholipids and proteins

E. proteins and actin filaments

D. phospholipids and proteins

Proteins do NOT pass through cell membranes because...

A. the membrane is made of protein

B. they contain nitrogen

C. they are very large molecules

D. they cause digestion of the cell

C. they are very large molecules

Permeability refers to...

A. the movement of molecules from an area of greater concentration to an area of lesser concentration

B. the extent to which a membrane allows a substance to pass through

C. the amount of solute in a solution

D. the ability to establish a permanent solute level in a solution

B. the extent to which a membrane allows a substance to pass through

Which statement is FALSE concerning movement of molecules across the cell membrane?

A. small uncharged molecules pass through easily

B. large molecules do not pass through easily.

C. charged molecules do not pass through easily

D. lipid molecules do not pass through easily

D. lipid molecules do not pass through easily

If 0.9% NaCl were isotonic to a cell, then...

A. 0.9% would also be hypotonic

B. 0.9% would also be hypertonic

C. 1.0% would be hypertonic

D. 1.0% would be hypotonic

E. 0.1% would be hypertonic

C. 1.0% would be hypertonic

If you have a 10% sugar solution and a 35% sugar solution, how does the 10% solution compare to the 35% solution?

A. isotonic

B. sweeter

c. osmotic

D. hypotonic

E. hypertonic

D. hypotonic

The term hypertonic means

A. to lose water

B. to gain water

C. a higher solute concentration

D. a lower solute concentration

E. an equal solute concentration

C. a higher solute concentration

An isotonic solution means that the solute concentration outside the cell...

A. is greater than inside the cell

B. is less than inside the cell

C. is the same as inside the cell

D. has no effect on the cell

E. is greater than outside the cell

C. is the same as inside the cell

Which is true of facilitated transport by carrier proteins?

A. Facilitated transport only applies to small and lipid soluble molecules

B. It is represented by the glucose carrier that can transport hundreds of molecules a second.

C. After a carrier has transported a molecule, it is unable to transport any more.

D. Facilitated transport requires expenditure of chemical energy and is therefore active transport.

E. One carrier protein can carry a variety of different molecules.

B. It is represented by the glucose carrier that can transport hundreds of molecules a second

Carrier molecules are required for

A. osmosis

B. both osmosis AND diffusion

C. facilitated diffusion

D. active transport

E. both facilitated diffusion AND active transport

E. both facilitated diffusion and active transport

When a substance moves rom an area of low concentration to an area of high concentration while using energy, the process is termed...

A. diffusion

B. osmosis

C. facilitated diffusion

D. active transport

D. active transport

If a cell lacks ATP, which of the following processes would cease to operate immediately?

A. diffusion

B. sodium/potassium pump

C. facilitated diffusion

D. osmosis

B. sodium/potassium pump

When an intestinal cell ingests substances inside very small vesicles that can only be seen with an electron microscope, this is...

A. pinocytosis

B. phagocytosis

C. exocytosis

D. diffusion

A. pinocytosis

Receptor-mediated endocytosis involves all of the following EXCEPT

A. receptor proteins to bind to specific molecules

B. a coated pit due to a layer of fibrous protein on the cytoplasmic side of the membrane

C. the mechanism for regulating exchange between a mother and fetus

D. secretion of materials from a cell

D. secretion of materials from a cell

Which of the following refers to materials only leaving the cell?

A. diffusion

B. exocytosis

C. endocytosis

D. phagocytosis

B. exocytosis

Which condition must be met for diffusion to occur?

A. a differentially permeable membrane

B. a true solution

C. a concentration difference

D. a non-permeable membrane

C. a concentration difference

Match the protein with its proper function.

1. Channel Protein

allows molecules to move through a membrnae through space provided by the protein

Match the protein with its proper function.

2. Carrier Protein

interacts and binds to a moleucle to help it move across a membrane, usually requiring a change in protein shape

Match the protein with its proper function.

3. Cell Recognition Protein

glycoproteins that allow cells of the immune systems determine if a cell belongs in the body or is an invader

Match the protein with its proper function.

4. Receptor Protein

binds to a specific extracellular molecule to bring about a change within the cell

Match the protein with its proper function.

5. Enzymatic Protein

catalyze specific reactions at the cell membrane

This is a multiple answer question. Choose all that are correct.

Following is a lsit of examples of the forms of movement of molecules across a membrane. Choose only those that require energy input from the cell whose membrane is directly involved.

A. Insulin starts out in a vesicle inside a beta cell of the pancreas. When blood sugar level rises the vesicle moves to the cell membrane and fuses with the cell membrane.

B. Glucose levels outside a cell are high and enter the cell through a carrier protein by facilitated diffusion.

C. Ldl cholesterol receptors fill up in a coated pit and the pit is pulled into the cell and made into a vesicle.

D. A person eats a salty snack and the salt concentration outside the cell rises. Water rushes out through aquaporins.

E. The cell uses a sodium-potassium pump to create a high concentration of sodium ions outside the cell.

A. Insulin starts out in a vesicle inside a beta cell of the pancreas. When blood sugar level rises the vesicle moves to the cell membrane and fuses with the cell membrane.

C. Ldl cholesterol receptors fill up in a coated pit and the pit is pulled into the cell and made into a vesicle.

E. The cell uses a sodium-potassium pump to create a high concentration of sodium ions outside the cell.

Glucose levels go up in the bloodstream after a meal. Beta cells of the pancreas detect the elevated glucose levels. This causes them to secrete insulin protein into the bloodstream. How is this secretion accomplished?

A. Motor proteins drag insulin-containing vesicles to the cell membrane along microtubules.

B. Insulin-containing vesicles diffuse to the cell membrane.

C. Insulin is exported from the cytoplasm by receptor mediated endocytosis.

D. Insulin is exported from the cytoplasm by facilitated diffusion with a carrier protein.

A. Motor proteins drag insulin-containing vesicles to the cell membrane along microtubules.

The GLUT protein

A. moves glucose across a membrane by simple diffusion

B. moves glucose across a membrane by facilitated diffusion

C. moves glucose across a membrane by active transport

D. moves glucose across a membrane by receptor mediated endocytosis.

B. Moves glucose across a membrane by facilitated diffusion

Which statement most accurately describes the second law of thermodynamics?

A. Energy cannot be changed from one form to another without a loss of usable energy.

B. One usable form of energy can be completely converted into another usable form.

C. Energy cannot be created nor destroyed but it can be changed from one form to another.

D. Energy cannot be created or destroyed.

A. Energy cannot be changed from one form to another without a loss of usable energy.

Which of the following statements most accurately describes the first law of thermodynamics?

A. One usable form of energy cannot be completely converted into another usable form.

B. One usable form of energy can be completely converted into another usable form.

C. Energy cannot be created or destroyed.

D. Energy can be neither created nor destroyed but it can be changed from one form to another.

D. Energy can be neither created nor destroyed but it can be changed from one form to another

Which of the following is NOT a correct statement about the second law of thermodynamics and entropy?

A. The amount of disorder in the universe is always increasing

B. To maintain organization of a cell, a continual input of energy is required.

C. Living cells without energy would become less organized

D. Carbon dioxide and water form glucose without the input of energy

D. Carbon dioxide and water form glucose without the input of energy

Occasionally someone claims to have built a machine that can run forever, producing as much energy as it consumes. This has always been disproved because it violates

A. the first law of thermodynamics

B.. the second law of thermodynamics

C. laws preventing any conversion between types of energy

D. coupled reactions equations

B. the second law of thermodynamics

The high energy bond in ATP that is used by cells is found in or between

A. the adenine base

B. the adenine and the ribose

C. the adenine and the phosphates

D. the phosphate groups

D. the phosphate groups

ATP contains

A. an adenine base and 2 phosphate groups

B. an adenine base and 3 phosphate groups

C. an adenine base, a ribose sugar, and 2 phosphate groups

D. an adenine base, a ribose sugar, and 3 phosphate groups

D. an adenine base, a ribose sugar, and 3 phosphate groups

The main reason that ATP is considered the energy currency in cells is because it

A. carriers a positive charge

B. contains accessible energy in phosphate bonds

C. contains an adenine base

D. contains a sugar ring

B. contains accessible energy in phosphate bonds

During an enzymatic reaction, what happens to the enzyme?

A. it becomes the product

B. it becomes the substrate

C. it is used up

D. the enzyme and the substrate from a temporary complex

D. the enzyme and the substrate from a temporary complex

Enzymes are specific. This means that they

A. have a preferred pH

B. have a preferred temperature

C. have a particular substrate

D. are only in certain cells

C. have a particular substrate

Which of the following statements is true about enzymes?

A. their 3D shape can vary and still be active

B. boiling temperatures do not affect their activity

C. they catalyze only one specific type of reaction

D. they can associate with a wide variety of substrates

E. They are unaffected by changes in pH

C. they catalyze only one specific type of reaction

Which is true about energy of activation?

A. Energy of activation is measured as the energy that is released after a reaction occurs.

B. Adding the correct enzyme can lower the energy of activation.

C. Energy of activation is the difference between the energy of the reactant and the energy of the product

D. The energy of activation is always lower than the energy of the reactant.

B. Adding the correct enzyme can lower the energy of activation.

Each enzyme has a particular substrate because enzymes

A. increase the energy of activation

B. decrease the productivity of the cell

C. have active sites complementary in shape to their substrates

D. are named for their substrate

C. have active sites complementary in shape to their substrates

The function of an enzyme is to

A. provide energy for metabolic reactions

B. increase the rate of a metabolic reaction

C. change the direction of metabolic reactions

D. raise the energy of activation for a reaction

B. increase the rate of a metabolic reaction

Which of the following statements is NOT true concerning enzymatic activity?

A. each enzyme has a preferred pH at which the enzyme reaction rate is highest

B. above a certain temperature, an enzyme will become denatured

C. As the temperature increases, most enzymatic reactions will still processed at the same rate

D. enzyme activity increases as substrate concentration increases until the maximum rate is achieved

C. as the temperature increases, most enzymatic reactions will still processed at the same rate

If you wished to increase enzyme activity, you would do all of the following except

A. increase the temperature moderately

B. increase the concentration of substrate

C. change to optimum pH for the reaction

D. decrease the tempertaure

D. decrease the temperature

If an enzymatic reaction was controlled by feedback inhibition, we would expect it to stop

A. only if the substrate was exhausted.

B. when the cofactors are exhausted.

C. when the product changed the pH.

D. as soon as a critical level of end product builds up.

D. as soon as a critical level of end product builds up.

In feedback inhibition of a metabolic pathway, where does the inhibitor bind?

A. to the substrate of the first reaction

B. to the product of the first reaction

C. to the enzyme of the first reaction

D. to a substrate or the product of the last reaction

C. to the enzyme of the first reaction

The location in which the enzyme and substrate complexes is called the

A. active site

B. inhibitor site

C. receptor site

D. enzyme-substrate complex

A. active site

If A --> B --> C --> D --> E represents a metabolic pathway, then letter E would be

A. a substrate

B. a product

C. energy

D. an enzyme

E. an enzyme-substrate complex

B. a product

This is a multiple choice question. Choose all that are correct.

In which of the following ways is the enzyme inhibitor warfarin used?

A. rat poison

B. anticoagulant medicine

C. recreational drug

D. cancer drug

A. rat poison

B. anticoagulant medicine

Which of the following can act as an enzyme cofactor?

A. iron

B. vitamines

C. NAD+

D. All of the above

D. all of the above

Some metabolic reactions require that one molecule undergoes a reaction that causes it to lose energy and that energy is then transferred to a new chemical bond on another molecule. This describes

A. a coupled reaction

B. an anabolic reaction

C. the activation energy of a reaction

D. feedback inhibition

A. a coupled reaction

If you give a child a sugary snack you might notice that they become hyperactive right afterward. Much of the sugar in the blood can be quickly broken down to create ATP. This is an example of which factor affecting rates of enzymatic reactions?

A. Substrate Concentration

B. Temperature

C. pH

D. Enzyme Inhibition

A. Substrate Concentration

While paddling your canoe down a river you notice many turtles laying on logs in the sun. This is an example of which factor affecting rates of enzymatic reactions?

A. Substrate Concentration

B. Temperature

C. pH

D. Enzyme Inhibition

B. Temperature

Which it NOT a correct attribute of a metabolic pathway?

A. A constant supply of new enzymes must be produced to keep the metabolic pathway active.

B. The product of one reaction can become the reactant for the next.

C. Reactants act as substrates for specific enzymes.

D. Reactants are the input molecules.

A. A constant supply of new enzymes must be produced to keep the metabolic pathway active.

We often say that we need food for energy. In a biological sense, is this correct?

A. Yes, because the food we eat has potential energy in its structure and this chemical energy can be converted into mechanical energy.

B. Yes, because the smallest units inside the atoms that make up the food are simply pure energy.

C. Yes, because the food must move through the digestive system, and motion is kinetic energy.

D. No, because food consists of matter and cannot be transformed into energy.

E. No, since all food matter stays matter, and energy remains energy.

A. Yes, because the food we eat has potential energy in its structure and this chemical energy can be converted into mechanical energy.

Put the reactions of cellular respiration in the correct order:

1. glycolysis

2. prep reaction

3. citric acid cycle

4. electron transport chain

Cellular respiration does NOT include which of the following events?

A. glycolysis

B. citric acid cycle

C. light reactions

D. electron transport chain

E. prep reaction

C. light reactions

Which molecules are the reactants or substrates for aerobic respiration?

A. glucose and carbon dioxide

B. carbon dioxide and water

C. oxygen and glucose

D. glucose and water

C. oxygen and glucose

Which molecules are the products of aerobic respiration?

A. glucose and water

B. glucose and oxygen

C. lactate and carbon dioxide

D. carbon dioxide and water

D. carbon dioxide and water

Which of the following is a substrate of cellular respiration?

A. carbon dioxide

B. water

C. glucose

D. energy

C. glucose

Which of the following does not describe the role of NAD+ in cellular respiration?

A. it accepts two electrons

B. it is a coenzyme

C. it is necessary for glycolysis

D. it is broken down to CO2 and water

D. it is broken down to CO2 and water.

What role does NAD+ play in cellular respiration?

A. It is a coenzyme.

B. It is an enzyme.

C. It provides the oxygen.

D. It provides the energy.

A. It is a coenzyme.

What are the input requirements of glycolysis?

A. NAD+, FAD, acetylCoA, and ADP

B. ATP, NAD+, glucose, and ADP

C. pyruvates, NADH, and ADP

D. glucose and oxygen

B. ATP, NAD+ glucose, and ADP

The final products of glycolysis are

A. pyruvate, ATP, and NADH + H +

B. pyruvate and ATP

C. pyruvate and NADH + H +

D. ATP and NADH + H +

E. pyruvate

A. pyruvate, ATP, and NADH + H +

Where does glycolysis take place within the cell?

A. endoplasmic reticulum

B. mitochondrial matrix

C. mitochondrial membrane

D. cytoplasm

D. cytoplasm

Choose the one correct statement.

A. Glycolysis results in the release of carbon dioxide.

B. Glycolysis is a cyclical reaction.

C. Glycolysis is a reduction reaction where only glucose is reduced.

D. Glycolysis occurs twice per glucose moleucle.

E. Glycolysis breaks glucose down to two pyruvate molecules.

E. Glycolysis breaks down glucose down to two pyruvate molecules

Muscles undergo fermentation when

A. no oxygen is available

B. no carbon dioxide is available

C. no ATP is available

D. no pyruvate is available

A. no oxygen is available

Pyruvate can be converted to lactate instead of going to the preparatory reaction. Why does this occur?

A. The cells need lactate to produce ATP.

B. The cells doing the reaction are prokaryotes.

C. Oxygen is not available.

D. There is a shortage of glucose.

C. Oxygen is not available.

Why do organisms without oxygen need to convert pyruvate to lactate?

A. in order to regenerate NAD+

B. because lactate is needed to produce ATP

C. because pyruvate is toxic to the cells

D. in order to use lactate in the citric acid cycle

A. in order to regenerate NAD+

What phase(s) of cellular respiration produce(s) NADH?

A. glycolysis

B. preparatory reaction

C. citric acid cycle

D. glycolysis and preparatory reaction

E. glycolysis, preparatory reaction, and citric acid cycle

E. glycolysis, preparatory reaction, and citric acid cycle

Which stage(s) will produce carbon dioxide in cellular respiration?

A. glycolysis

B. preparatory reaction

C. citric acid cycle

D. both glycolysis and the electron transport chain

E. both the preparatory reaction and the citric acid cycle

E. both the preparatory reaction and the citric acid cycle

The largest number of ATP molecules is produced in which phase of cellular respiration?

A. glycolysis

B. preparation reaction

C. citric acid cycle

D. electron transport chain

D. electron transport chain

Pyruvate is converted to a two-carbon acetyl group attached to coenzyme A (CoA), and CO2 is given off. This phase is called

A. substrate-level ATP synthesis.

B. the preparatory reaction.

C. the citric acid cycle.

D. fermentation.

B. the preparatory reaction.

Which of the following statements is NOT true?

A. The end product of glycolysis is pyruvate.

B. The citric acid cycle begins and ends with pyruvate.

C. NADH2 will eventually produce three ATP molecules.

D. Aerobic respiration uses oxygen and releases carbon dioxide.

B. The citric acid cycle begins and ends with pyruvate.

Which pathway in cellular respiration will produce ATP, NADH, and carbon dioxide?

A. glycolysis

B. preparatory reaction

C. citric acid cycle

D. electron transport chain

C. citric acid cycle

The production of ATP as a result of an electrochemical gradient is called

A. substrate-level phosphorylation.

B. chemiosmosis.

C. deamination.

D. substrate level phosphorylation.

B. chemiosmosis.

Why does chemiosmosis require a membrane?

A. to anchor proteins within the mitochondria

B. because the phospholipids are involved in the electron transport chain

C. to separate two compartments of the cell to allow for gradient formation

D. to generate H+ from water

C. to separate two compartments of the cell to allow for gradient formation

What is the final electron acceptor at the end of the electron transport chain in respiration?

A. Oxygen

B. Water

C. NADH

D. ADP

A. Oxygen

Which molecules donate electrons to the electron transport chain of respiration?

A. NADH and FAD

B. ATP and ADP

C. Water and Oxygen

D. Carbon Dioxide and Water

A. NADH and FAD

Where is NAD+ converted to NADH?

A. Cytoplasm and Matrix of the Mitochondrion

B. Cytoplasm Only

C. Matrix of the Mitochondrion Only

D. Intermembrane Space of the Mitochondrion Only

A. Cytoplasm and Matrix of the Mitochondrion

ATP and ADP have a strong negative charge. How could that get into and out of the mitochondrion?

A. Through a membrane transport protein.

B. By diffusion throught the phospholipid bilayer.

C. Diffusion through the mitochondrial membranes since those membranes are not made of phospholipids.

D. By endocytosis and exocyctosis of the mitochondrial membranes.

A. Through a membrane transport protein.

What are the products of photosynthesis?

A. water and carbon dioxide

B. carbohydrate and water

C. oxygen and carbohydrate

D. carbon dioxide and carbohydrate

C. oxygen and carbohydrate

The raw materials or reactants of the photosynthetic process include

A. glucose and oxygen.

B. carbon dioxide and glucose.

C. carbon dioxide and water.

D. glucose and water.

C. carbon dioxide and water.

At the cellular level, photosynthesis occurs within

A. the chloroplast.

B. the cristae of the mitochondria.

C. both chloroplasts and mitochondria.

D. all plant cell organelles.

A. the chloroplast.

Solar energy is captured by

A. pigments.

B. nucleus.

C. glucose.

D. NAD+.

A. pigments.

Which of the following statements is TRUE concerning sunlight radiation used for photosynthesis?

A. All of the sunlight that hits the atmosphere is used for photosynthesis.

B. Only the highest energy wavelengths are used for photosynthesis.

C. Only the red, blue, and violet wavelengths of visible light are used for photosynthesis.

D. Only the green visible light is used for photosynthesis.

C. Only the red, blue, and violet wavelengths of visible light are used for photosynthesis.

Why are plant leaves green?

A. They absorb only green wavelengths of light.

B. They absorb only yellow and blue wavelengths of light.

C. They reflect green wavelengths of light.

D. They reflect yellow and blue wavelengths of light

C. They reflect green wavelengths of light.