Cellule e genoma, test a risposta multipla in inglese con risposte

Cells and genomes test

1. Shared characteristics among newly discovered organisms

Scientists discover more than ten thousand new species of living organisms every year. What is shared between all of these organisms?

• A. They are made of cells, whose nuclei enclose their DNA.
• B. They obtain their energy from sunlight.
• C. They produce and use adenosine triphosphate (ATP).
• D. Their genome contains at least 1000 genes.
• E. All of the above.

2. Characteristics of all cells

All cells …

• A. have membrane transport proteins.
• B. synthesize proteins on the ribosome.
• C. replicate their genome by DNA polymerization.
• D. transcribe their genetic information by RNA polymerization.
• E. All of the above.

3. Information translation from DNA to protein

Imagine a segment of DNA (within a gene) encoding a certain amount of information in its nucleotide sequence. When this segment is fully transcribed into mRNA and then translated … into protein, in general,

• A. the protein sequence would carry more information compared to the DNA and mRNA sequences, because its alphabet has 20 letters.
• B. the protein sequence would carry less information compared to the DNA and mRNA sequences, because several codons can correspond to one amino acid.
• C. the amount of information in the mRNA sequence is lower, because the mRNA has been transcribed using only one of the DNA strands as the template.
• D. the amount of information in the mRNA sequence is higher, because several mRNA molecules can be transcribed from one DNA molecule.

4. Cellular processes not requiring energy

Which of the following processes that happens inside a cell does not normally require consumption of free energy by the cell?

• A. Replication of the genetic material
• B. Import of nutrients from the environment
• C. Diffusion of small molecules within the cell
• D. Regulation of gene expression
• E. Synthesis of enzymes that catalyze cellular reactions

5. Features absent in bacterial cells

Which of the following would you not expect to find in a bacterial cell?

• A. Swimming using flagella
• B. Having a cell wall around the plasma membrane
• C. ATP production in mitochondria
• D. Protein production on the ribosome
• E. Sexual exchange of DNA with other bacteria

6. Tracing family relationships in organisms

To trace family relationships between distantly related organisms such as humans, algae, … bacteria, and archaea, one should compare their genomes in regions …

• A. that evolve rapidly.
• B. that have a higher mutation rate.
• C. that code for proteins.
• D. where mutations are hardly tolerated.
• E. where most mutations are selectively neutral.

7. Antibiotic-resistant E. coli in research

Laboratory strains of the model organism Escherichia coli that are resistant to antibiotics are very often used in research laboratories as well as in the biotechnology industry. If cultures of such bacteria were allowed to contaminate the environment uncontrollably, it is possible that at some point, pathogenic bacteria …