Ok this is the third time posting.

How does gene duplication allow new genes to develop over many generations? Select two answer choices.

a. If the original gene becomes non-functional because of a mutation, it will be selected against and could be deleted because it accumulates further mutations over time to eventually become a non-functional gene.

b. In organisms with duplicated genes, the original gene and its function is maintained while allowing mutations to occur in the duplicated gene that can lead to new variations.

c. In organisms with duplicated genes, the original gene and its function is deleted while allowing mutations to occur in the duplicated gene that can lead to new variations.

d. If the duplicated gene becomes non-functional because of a mutation, it will not be selected against and could accumulate further mutations over time to eventually become a gene with new functions.

You have been asked to lead a demonstration for the undergraduate microbiology lab course about the uses of negative staining when studying bacteria. a "negative" stain does not stain the bacterial cell itself but stains the space between cells. under magnification, the acidic (negativelycharged) nature of the stain will be repelled by the negatively charged bacterial cell wall and willleave the cell colorless in a stained background. negative stains are used primarily to reveal the presence of negatively charged bacterial capsules; therefore, they are also called capsule stains. encapsulated cells appear to have a halo surrounding them. the negative stain procedure does not require heat fixation, which limits any chances of alteration in bacterial cell shape and size. the bacterial suspension is added to a drop of stain, such as nigrosin or eosin, and drawn across the glass slide using a coverslip. nigrosin staining-not safranin staining-of klebsiella pneumoniae will allow for the visualization of the cell shape and the determination of the presence of a capsule. true/false

The finches on the galapagos island were similar in form except for variations of their beaks. darwin observed that these variations were useful for: attracting a mate defending territory building nests gathering food

All vaccination should(n’t) be mandatory! 1.at least 5 sentences explaining 2.why? 3.in the end summarize the sentence