Q: Which of the following equations correctly represents the relationship between codons and amino acids in the genetic code?

$$61 \ \text{codons} \rightarrow 20 \ \text{amino acids}$$

Question 1

Which of the following statements best summarizes the cell theory?

Accepted Answer

All living organisms are made of cells, and all cells arise from pre-existing cells.

Question 2

Which of the following is a unique feature of prokaryotic cells compared to eukaryotic cells?

Accepted Answer

They lack a membrane-bound nucleus.

Question 3

Which of the following macromolecules is correctly matched with its monomer?

Accepted Answer

Protein – Amino Acid

Question 4

A scientist discovers a new single-celled organism with a circular chromosome, no nucleus, and a cell wall made of peptidoglycan. To which domain does this organism most likely belong?

Accepted Answer

Bacteria

Question 5

Which of the following best describes the function of ribosomes in all cells?

Accepted Answer

They translate mRNA into proteins.

Question 6

Which of the following equations correctly represents the relationship between codons and amino acids in the genetic code?

Accepted Answer

$$61 \ 	ext{codons} ightarrow 20 \ 	ext{amino acids}$$

Question 7

Which of the following is NOT a function of the plasma membrane in cells?

Accepted Answer

Synthesizing proteins for the cell

Question 8

A bacterium is found to have a plasmid that confers antibiotic resistance. Which of the following statements about plasmids is correct?

Accepted Answer

Plasmids can be shared between bacteria, allowing rapid evolution.

Question 9

Which of the following best explains why bacterial cell walls are important for survival in hypotonic environments?

Accepted Answer

They prevent the cell from bursting due to osmotic pressure.

Question 10

Which of the following is a real-world application of bacterial flagella?

Accepted Answer

Transferring DNA between bacteria during conjugation

Question 11

Which of the following best describes the role of tRNA during translation?

Accepted Answer

It carries amino acids to the ribosome based on the mRNA codon sequence.

Question 12

Which of the following is a correct statement about the diversity of life and the three domains?

Accepted Answer

Bacteria and Archaea are both prokaryotes, while Eukarya includes all eukaryotic organisms.

Question 13

A researcher is studying a bacterium that can nucleate ice crystals and is used in artificial snow production. Which protein function is most directly involved in this process?

Accepted Answer

Positioning water molecules to form a solid structure

Question 14

Which of the following best describes the structure of a bacterial chromosome?

Accepted Answer

A single circular DNA molecule located in the nucleoid

Question 15

Which of the following is a correct match between a macromolecule and its primary function in the cell?

Accepted Answer

Carbohydrates – Chemical energy and structural support

Question 16

Which of the following best explains why all cells, regardless of type, have a plasma membrane composed of phospholipids?

Accepted Answer

Phospholipids form a selective barrier that protects the cell and maintains homeostasis.

Question 17

Which of the following scenarios best illustrates the concept of quorum sensing in bacteria?

Accepted Answer

A population of bacteria releases signaling molecules to coordinate gene expression once a critical density is reached.

Question 18

Which of the following best describes the role of histone-like proteins in prokaryotes?

Accepted Answer

They help organize and compact the bacterial chromosome within the nucleoid.

Question 19

Which of the following is a correct statement about the cytosol in cells?

Accepted Answer

It is a gel-like fluid containing water, nutrients, salts, and proteins inside the plasma membrane.

Question 20

A bacterium is found in a toxic waste dump, breaking down harmful chemicals. Which property of prokaryotes allows them to adapt rapidly to such environments?

Accepted Answer

The ability to share plasmids containing beneficial genes

Cells: The Basic Unit of Life – Structure, Diversity, and Common Features

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