Bio Review - 1

RNA nucleotides contain which components?

• a phosphate group, a nitrogenous base, and deoxyribose

• a nitrogenous base, ribose, and DNA polymerase

• a phosphate group, deoxyribose, and ribose

• a phosphate group, a nitrogenous base, and ribose

What is one function of protein?

• catalyze chemical reactions

• compose cellulose for plant support

• form waxy, waterproof coverings

• provide source of fiber in the diet

There are only twenty different amino acids in living things, but there are thousands of different proteins. Which statement best explains why this is true?

• The type of protein is determined by the number of peptide bonds it has.

• The type of protein is determined by the order in which the amino acids bond.

• The type of protein is determined by the number of hydrogen bonds it has.

• The type of protein is determined by the order in which the nucleotides bond.

DNA is responsible for passing on genetic information from one generation to the next, so DNA must be present in the reproductive cells of the human body. It is also present in the non-reproductive cells of the body.

Which statement best explains the reason for this fact?

• DNA remains inactive in non-reproductive cells.

• DNA is essential to form proteins required for cell function.

• DNA helps the non-reproductive cells transport amino acids.

• DNA provides all cells with the required energy to function.

Hydrogen peroxide naturally breaks down into oxygen and water over time. When exposed to the enzyme catalase, hydrogen peroxide is rapidly converted into oxygen and water.

What feature of catalase most likely is responsible for the change in the rate of conversion of hydrogen peroxide into water and oxygen?

• Catalase speeds up the conversion of hydrogen peroxide into water and oxygen by by decreasing the reaction's activation energy.

• Catalase bonds permanently with the reactants causing hydrogen peroxide to rapidly break down by increasing the activation energy.

• Catalase has a flexible structure that allows it to bind and convert any small hydrogen hydrogen containing compound into water and oxygen.

• Catalase remains intact, so small amounts of it convert large amounts of hydrogen peroxide into water and oxygen immediately.

Why is it important for stomach acid to maintain a pH of 2?

• If the pH of the stomach changes too much, the cellular membrane of stomach cells will change shape.

• The low concentration of H+ in the stomach helps to break down cellulose from fruitsand vegetables.

• Without a pH of 2, the digestive enzymes in the stomach will change shape and will notfunction properly

• Maintaining a pH of 2 is critical for the function of DNA, which produces digestive enzymes

Which two organelles in the cell must work together in the process of protein production?

• The nucleus produces DNA that directs protein production in the mitochondria.

• The nucleus produces RNA that directs protein production in the ribosomes.

• The ribosomes produce amino acids that direct protein production in the mitochondria.

• The ribosomes produce peptides that direct protein production in the nucleus.

Vesicles are important membrane-bound organelles that serve many roles in the cell. Which sequence represents a correct pathway that vesicles would follow in helping to deliver a protein for export from the cell?

• chloroplast → Golgi apparatus → mitochondrion

• ribosome → Golgi apparatus → cell membrane

• rough ER → smooth ER → cell wall

• smooth ER → mitochondrion → vacuole

E. coli and a mammalian cell both contain DNA. However, E. coli is a prokaryotic cell, and a mammalian cell is a eukaryotic cell.

What is one reason for classifying E. coli as a prokaryotic cell?

• The DNA of

  E. coli contains fewer base pairs.

• The DNA of

  E. coli does not undergo transcription.

• The DNA of

  E. coli replicates twice prior to cell division.

• The DNA of

  E. coli is not enclosed in a nuclear membrane.

There are two types of living organisms: prokaryotes and eukaryotes.

Which statement is correct regarding the organism shown in the diagram?

• As a unicellular eukaryote, this organism does not have to carry out all of life’s activities

• As a unicellular prokaryote, this organism does not have to carry out all of life’s activities

• As a unicellular eukaryote, this organism must carry out all of life’s activities.

• As a unicellular prokaryote, this organism must carry out all of life’s activities.