Observations of cells in stages of cell cycle
sample: number of cells in interphase number of cells in prophase number of cells in metaphase number of cells in anaphase number of cells in telophase
sample a 6 15 4 7 8
sample b 25 4 2 3 1
sample c 4 9 5 3 6

you are observing different tissue samples and classifying the cells into their respective stage in the cell cycle. using what you know about cancer cells, formulate which sample do you suspect contains cancer cells?
a) sample b is is most likely cancerous because most of the cells are in interphase.
b) sample b is most likely cancer tissue because most cells are in some stage of mitosis.
c) only sample a indicates possible cancer cells due to the high number of cells in prophase.
d) samples a & c indicate cancer due to the large proportion of cells in some stage of mitosis compared to the cells in interphase.

What protects the lining of the stomach from acidic gastric juices?

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

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection