Question 1

Which of the following best describes the primary structure of DNA?

Accepted Answer

The sequence of nucleotides linked by phosphodiester bonds

Question 2

A scientist is studying a cell with an extensive network of rough endoplasmic reticulum (ER) and numerous vesicles. Which function is this cell most likely specialized for?

Accepted Answer

Secreting proteins

Question 3

Which of the following statements about the nuclear envelope is correct?

Accepted Answer

It consists of a double phospholipid bilayer with nuclear pores that regulate macromolecule passage.

Question 4

Which of the following is true regarding the difference between ribose and deoxyribose sugars in nucleic acids?

Accepted Answer

Ribose contains a 2' OH group, while deoxyribose lacks the 2' OH group.

Question 5

A mutation disrupts the function of the Golgi apparatus in a pancreatic cell. Which of the following processes would be most directly affected?

Accepted Answer

Modification and packaging of proteins for secretion

Question 6

Which type of covalent bond links nucleotides together in the backbone of DNA and RNA?

Accepted Answer

Phosphodiester bond

Question 7

During the Meselson & Stahl experiment, proteins synthesized in the rough ER were tracked using radioactive amino acids. What was the correct sequence of organelles these proteins passed through before secretion?

Accepted Answer

Rough ER → Golgi apparatus → secretory vesicles

Question 8

Which of the following best explains why lysosomes maintain an internal pH of 5?

Accepted Answer

Their hydrolytic enzymes function optimally at acidic pH.

Question 9

Which of the following is NOT a function of the smooth endoplasmic reticulum (ER)?

Accepted Answer

Synthesis of proteins for secretion

Question 10

A nucleotide is composed of which three components?

Accepted Answer

A nitrogenous base, a pentose sugar, and a phosphate group

Question 11

Which of the following best describes the secondary structure of DNA?

Accepted Answer

Two antiparallel strands held together by hydrogen bonds and twisted into a double helix

Question 12

Which of the following is a unique feature of animal cells compared to plant cells?

Accepted Answer

Presence of lysosomes

Question 13

If a cell is unable to produce sufficient nucleotides, which dietary deficiency is most likely responsible?

Accepted Answer

Deficiency in nitrogen and phosphorus

Question 14

Which of the following best explains why proteins destined for secretion begin synthesis in the cytoplasm but complete synthesis in the rough ER?

Accepted Answer

A signal sequence directs the ribosome to the ER, where translation is completed and the protein enters the ER lumen.

Question 15

Which of the following is a correct statement about the nucleolus?

Accepted Answer

It is the site where ribosomal RNA is transcribed.

Question 16

Which of the following best describes the role of nuclear pores?

Accepted Answer

They allow selective passage of macromolecules between the nucleus and cytoplasm.

Question 17

Which of the following is a correct pairing of a DNA nitrogenous base with its complementary base?

Accepted Answer

Adenine (A) pairs with Thymine (T)

Question 18

A cell is observed to have a high number of lysosomes. Which of the following is the most likely function of this cell?

Accepted Answer

Digesting and recycling cellular waste

Question 19

Which of the following best explains why the endoplasmic reticulum (ER) is considered part of the endomembrane system?

Accepted Answer

It is continuous with the nuclear envelope and involved in the synthesis and transport of biomolecules.

Question 20

Which of the following is a real-world consequence of a genetic mutation that disrupts phosphodiester bond formation in DNA?

Accepted Answer

The DNA backbone would be unstable, leading to genetic diseases due to improper DNA replication.

Cells, Organelles, and Biomolecules: Structure and Function

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