Unit 6 AP Biology Review

Which enzyme catalyzes the elongation of a DNA strand in the 5ʹ → 3ʹ direction?

• primase

• DNA ligase

• DNA Polymerase

• helicase

What determines the nucleotide sequence of the newly synthesized strand during DNA replication?

• the nucleotide sequence of the template strand

• the primase used in the reaction

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent

• leading strands and Okazaki fragments

• lagging strands and Okazaki fragments.

Explain how the structure of the cell membrane contributes to its function.

• The rigid structure provides support and protection.

• The fluid mosaic model allows selective permeability.

• The thick layer prevents all substances from entering.

• The solid structure allows for easy transport of materials.

Which of the following best describes the function of the nucleolus within the nucleus?

• It stores DNA.

• It synthesizes ribosomal RNA.

• It regulates cell division.

• It modifies proteins.

How does the structure of the cytoskeleton contribute to its function in the cell?

• Its rigid structure provides a fixed shape to the cell.

• Its dynamic nature allows for cell movement and stability.

• Its solid form prevents the cell from collapsing.

• Its impermeable nature protects the cell from external substances.

Describe the role of ribosomes in a cell.

• They store genetic information.

• They synthesize proteins.

• They break down waste materials.

• They transport substances across the cell membrane.

Compare and contrast the functions of the smooth and rough endoplasmic reticulum.

• Both synthesize proteins; the rough ER also detoxifies chemicals.

• The smooth ER synthesizes lipids; the rough ER synthesizes proteins.

• Both store calcium ions; the smooth ER also synthesizes proteins.

• The rough ER detoxifies chemicals; the smooth ER stores genetic material.

A cell is observed to have a large number of lysosomes. What might this indicate about the cell's function?

• It is involved in energy production.

• It is involved in protein synthesis.

• It is involved in waste processing and recycling.

• It is involved in lipid storage.

Tags

NGSS.HS-LS2-3

Which organelle is responsible for modifying, sorting, and packaging proteins for secretion?

• Ribosome

• Golgi apparatus

• Endoplasmic reticulum

• Lysosome