A2.3. Viruses (HL only)

The image shows an electron micrograph of virus particles known to infect the bacterium Vibrio parahaemolyticus, which is associated with gastroenteritis, wound infections and septicemia in humans and animals.

[Source: Lin, Y. and Lin, C., 2012. Transmission electron micrograph of phage ϕpp2 particles with several structural proteins. [micrograph] (BMC Genomics, 13:224).]

What does a virus have in common with a living cell?

A. 70S ribosomes

B. Genetic material

C. Reproduction by binary fission

D. Anaerobic respiration

The image shows an electron micrograph of virus particles known to infect the bacterium Vibrio parahaemolyticus, which is associated with gastroenteritis, wound infections and septicemia in humans and animals.

[Source: Lin, Y. and Lin, C., 2012. Transmission electron micrograph of phage ϕpp2 particles with several structural proteins. [micrograph] (BMC Genomics, 13:224).]

What does a virus have in common with a living cell?

A. 70S ribosomes

B. Genetic material

C. Reproduction by binary fission

D. Anaerobic respiration

The image shows a group of enveloped viral particles.

_{[Source: Murphy, F. and Whitfield, S., n.d. Herpes virus image under the microscope. [image online] Available at: https://www.bbvaopenmind.com/en/science/research/virus-inspired-science/ [Accessed 3 July 2020].]}

What is the most likely composition of the structure labelled X?

A.  Membrane derived from the host cell

B.  Viral DNA

C.  Viral cell walls

D.  Viral enzymes

The image shows a group of enveloped viral particles.

_{[Source: Murphy, F. and Whitfield, S., n.d. Herpes virus image under the microscope. [image online] Available at: https://www.bbvaopenmind.com/en/science/research/virus-inspired-science/ [Accessed 3 July 2020].]}

What is the most likely composition of the structure labelled X?

A.  Membrane derived from the host cell

B.  Viral DNA

C.  Viral cell walls

D.  Viral enzymes

The image shows a group of enveloped viral particles.

_{[Source: Murphy, F. and Whitfield, S., n.d. Herpes virus image under the microscope. [image online] Available at: https://www.bbvaopenmind.com/en/science/research/virus-inspired-science/ [Accessed 3 July 2020].]}

What is the most likely composition of the structure labelled X?

A.  Membrane derived from the host cell

B.  Viral DNA

C.  Viral cell walls

D.  Viral enzymes

The image shows a group of enveloped viral particles.

_{[Source: Murphy, F. and Whitfield, S., n.d. Herpes virus image under the microscope. [image online] Available at: https://www.bbvaopenmind.com/en/science/research/virus-inspired-science/ [Accessed 3 July 2020].]}

What is the most likely composition of the structure labelled X?

A.  Membrane derived from the host cell

B.  Viral DNA

C.  Viral cell walls

D.  Viral enzymes

Deduce the concentration of ZDV that would cause a 50 % reduction in root growth compared to the control.

Identify the root length, as a percentage of the control, resulting from a ZDV concentration of $400 \text{μmol}$.

Compare and contrast the effect of ZDV and NVP on the growth of Allium roots.

Deduce the concentration of ZDV that would cause a 50 % reduction in root growth compared to the control.

Identify the root length, as a percentage of the control, resulting from a ZDV concentration of $400 \text{μmol}$.

Compare and contrast the effect of ZDV and NVP on the growth of Allium roots.

Deduce the concentration of ZDV that would cause a 50 % reduction in root growth compared to the control.

Identify the root length, as a percentage of the control, resulting from a ZDV concentration of $400 \text{μmol}$.

Compare and contrast the effect of ZDV and NVP on the growth of Allium roots.