Bacteria, Viruses & Ecosystems

What does invading the host cell enable the virus to do?

• increase its size
• synthesize needed oxygen
• obtain nutrients
• reproduce

The diagram represents a cycle initiated when a virus (bacteriophage) infects a bacterial cell. Which nutritional relationship exists between the virus and the bacterial cell?

• parasitism
• mutualism
• commensalism
• saprophytism

The substance being transferred into the bacterial cell in B is

• a nucleic acid
• a protein
• an enzyme
• a hormone

Nitrogen-fixing bacteria live on the roots of leguminous plants in swellings called nodules. The bacteria synthesize nitrogen compounds that are used by the plants, and the plants provide moisture and nutrients for the bacteria. The interaction between the nitrogen-fixing bacteria and the leguminous plants is known as

• parasitism
• mutualism
• saprophytism
• commensalism

What does a virus have on the inside?

• DNA, but never RNA
• RNA but never DNA
• DNA or RNA
• neither DNA or RNA

Why are viruses considered to be nonliving organism?

• they do not have genetic information
• they are not able to move on their own
• they do not interact with their environment
• they are no able to reproduce without a host cell

All viruses are different, but what are two parts that a virus must have?

• Genetic Information (DNA or RNA)

• a lipid membrane

• a nucleus

• a protein coat

Which of these statements is true?

• A virus is unicellular, it has only one cell.

• A virus may sometimes be multicellular, have many cells.

• A virus has no cells

What is the name of this virus

• Capsule

• Helical

• Bacteriophage

• Teva (my dog)

Which processes allows for the viruses DNA to lay "dormant" or hide in the host DNA while the cell reproduces?

• Lytic

• Lysogenic

• Enveloped

• Capsid