Biology Test Biology Microbiology and Biotechnology 4

Question 1

Which of the following best describes the lytic cycle of a bacteriophage?

Accepted Answer

The phage replicates within the host and lyses the cell to release new phages

Answer

In the lytic cycle, the phage hijacks the bacterial cell's machinery to replicate, then destroys (lyses) the host cell to release new phage particles.

Question 2

What is the function of telomerase in cancer cells?

Accepted Answer

It extends telomeres, preventing cellular senescence

Answer

Telomerase extends telomeres at the ends of chromosomes, allowing cancer cells to divide indefinitely without entering replicative senescence.

Question 3

Which biosafety level (BSL) is required for working with agents that pose a high risk of life-threatening disease with no vaccine or therapy?

Accepted Answer

BSL-4

Answer

BSL-4 laboratories handle the most dangerous pathogens (e.g., Ebola, Marburg) that pose a high risk of aerosol-transmitted infection with no available treatment.

Question 4

What is the role of Taq polymerase in PCR?

Accepted Answer

It synthesizes new DNA strands at elevated temperatures

Answer

Taq polymerase, isolated from Thermus aquaticus, is a heat-stable DNA polymerase that synthesizes new DNA during the extension step of PCR at ~72°C.

Question 5

Which type of symbiosis describes the relationship between nitrogen-fixing Rhizobium bacteria and legume roots?

Accepted Answer

Mutualism

Answer

Rhizobium and legumes share a mutualistic relationship: the bacteria receive carbon from the plant while fixing atmospheric nitrogen for the plant's use.

Biology Practice Test

Biology Practice Test

Biology Test Biology Microbiology and Biotechnology 4