The lens within an eye focuses light onto the
a. iris.
b. retina.
c. pupil.
d. cornea.

What causes fermentation a. antibodies b. antigens c. microorganisms d. antibiotics

Which of the following statements describes the lysogenic cycle of lambda (λ) phage? a) after infection, the viral genes immediately turn the host cell into a lambda-producing factory, and the host cell then lyses.b) most of the prophage genes are activated by the product of a particular prophage gene.c) the phage genome replicates along with the host genome.d) the phage dna is copied and exits the cell as a phage.

You isolate an infectious substance capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, viroid, or prion. you have four methods at your disposal to analyze the substance and determine the nature of the infectious agent.i. treat the substance with enzymes that destroy all nucleic acids and then determine whether the substance is still infectious.ii. microscope.iii. culture the substance on nutritive medium, away from any plant cells.iv. treat the sample with proteases that digest all proteins and then determining whether the substance is still infectious.if you already know that the infectious agent was either bacterial or viral, which method(s) listed above would allow you to distinguish between these two possibilities? a) ib) iic) ii or iiid) iv