Bio101 Chapter 6 |151 Questions| With Correct Answers.

Which of the following statements best explains how a modern transmission electron microscope (TEM) can achieve a resolution of about 2.0 nanometers, whereas a standard light microscope has a maximum resolution of about 200 nanometers? ~Staining with atoms of heavy metal provides higher contrast that the colored dyes used in light microscopy. ~The wavelengths of electron beams are much shorter than the wavelengths of visible light. ~TEMs utilize much higher quality glass lenses than those found in light microscopes. ~Specimens visualized by TEM are much thicker than those observed by light microscopy. {Ans: The wavelengths of electron beams are much shorter than the wavelengths of visible light.}The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell. ~plasma membrane ~nucleoid region ~ribosome ~pili ~cell wall {Ans: plasma membrane}Where is a bacterial cell's DNA found? ~ribosomes ~nucleus ~peroxisome ~nucleoid region ~capsule {Ans: nucleoid region}what protein? ATP synthase {Ans: integral protein}Passive leakage of partially digested material from the small intestine into the human abdominal cavity may result from defects in which of the following type of intercellular junction? ~plasmodesmata ~desmosomes ~tight junctions ~gap junctions