Final answer:
In a yeast cell, the structures that would be stained by methylene blue, a dye that binds to DNA, would include the nucleus (which contains chromosomal DNA) and the mitochondria (which contain their own small circular DNA).
Step-by-step explanation:
Methylene blue, a type of dye, has a strong affinity towards DNA and hence it is often used in molecular biology applications. In a yeast cell, structures that contain DNA would get stained by this dye. The primary structure that would be stained by methylene blue in a yeast cell would be the nucleus, which harbors the chromosomal DNA. Additionally, yeast cells also contain small, circular DNA molecules inside their mitochondria, which also would be stained.
For instance, let's consider a yeast species like Saccharomyces cerevisiae. During the meiotic phases of these yeast cells, chromosomes align and segregate, which could be distinctly visualized with the assistance of a DNA bind dye like methylene blue. Since DNA is the genetic material and found in every active cell, every yeast cell undergoing cell division would theoretically show staining.
In conclusion, any structure in a yeast cell containing DNA would be stained by methylene blue, with the nucleus and mitochondria being the most noteworthy examples.
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