Question

1. heat fixing a bacterial smear kills the bacteria and adheres them to the slide.

true.

1. over-decolorization during gram staining can cause gram-positive bacteria to appear

gram-negative.

Explanation:

Question 7

Heat fixing in microbiology (a subfield of Biology, Natural Science) kills bacteria by denaturing their proteins and also makes them adhere to the slide so they don't wash off during staining. So the statement is true.

In Gram staining (a technique in Microbiology, Biology), over - decolorization removes too much of the crystal violet - iodine complex from Gram - positive bacteria. Since Gram - positive bacteria rely on retaining this complex, over - decolorization can make them lose the purple color and take up the counterstain (like safranin) used for Gram - negative bacteria, making them appear Gram - negative. So the statement is true.

Answer:

TRUE

Question 8