pg. 1 Straighterline Micro 250 Final Exam Prep Latest Update 2024 -2025 Actual Exam Questions with Correct Verified Answers/ Graded A+
The purpose of staining cells on a microscope slide is to ______.
Select one:
- kill them
- secure them to the slide
- enlarge the cells
- add contrast to see them better
- observe motility - Correct Answer - add contrast to see them better
Many chronic infections are caused by microbes that associate in communities termed
______.
Select one:
- biofilms
- virions
- sediments
- microbiota - Correct Answer – biofilms
Microorganisms are best defined as organisms that
Select one:
- cause human disease.
- lack a cell nucleus.
- are infectious particles.
- are too small to be seen with the unaided eye. 1 / 4
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- can only be found growing in laboratories. - Correct Answer - are too small to be
seen with the unaided eye.
Studies of the immune response to an infection caused by microorganisms would be performed by a(n) ______.
Select one:
- hypersensitivity specialist
- epidemiologist
- immunologist
- geomicrobiologist - Correct Answer - immunologist
Robert Koch and his colleagues first used agar in bacteriological media. Why was this ingredient an improvement on previous materials used to culture bacteria?
Select one:
- Bacteria growing on the solidified medium did not degrade or break down the agar.
- Agar can convert from liquid to solid form, and back again, very easily.
- Agar was less expensive than the nutrients that Koch was previously using in the lab.
- Agar is a complete source of nutrients for most bacteria. - Correct Answer - Bacteria
growing on the solidified medium did not degrade or break down the agar.
An example of an amphipathic molecule found in living cells is ______.
Select one:
- glucose
- phospholipid
- protein
- nucleic acid
- ATP - Correct Answer - phospholipid
A diagram of the three domains (Bacteria, Archaea, Eukarya) proceeding from the Last Universal Common Ancestor would show Archaea 2 / 4
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Select one:
- as the original cells from which the others derived.
- branching off the Domain Eukarya.
- branching off the Domain Bacteria. - Correct Answer - branching off the Domain
Eukarya
An atom has gained an electron; it has been ______.
Select one:
- oxidized
- reduced
- ionized
- deionized
- neutralized - Correct Answer - reduced
Analysis of the small subunit rRNAs from all organisms in the three current domains suggests that
Select one:
- the eukaryotes arose from prokaryotes.
- the Archaea are more closely related to bacteria than eukaryotes.
- all modern and extinct organisms on earth arose from a common ancestor.
- the prokarytoes, archaea, and eukaryotes are not related. - Correct Answer - c. all
modern and extinct organisms on earth arose from a common ancestor.
Most biochemical macromolecules are polymers, which are chains of ______.
Select one:
- hydrophobic molecules
- electrolytic molecules
- repeating monomers
- repeating carbohydrates 3 / 4
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- hydrogen bonds - Correct Answer - repeating monomers
A nutrient medium that contains at least one ingredient that is not chemically defined is termed ______.
Select one:
- complex
- reducing
- enriched
- synthetic - Correct Answer - complex
One nucleotide contains one
Select one:
- phosphate.
- pentose sugar.
- nitrogen base.
- All of the choices are correct. - Correct Answer - All of the choices are correct.
Characteristics shared by all cells include
Select one:
- a membrane serving as a cell boundary.
- the possession of genetic information.
- the presence of cellular fluid.
- All of the choices are correct. - Correct Answer - All of the choices are correct.
The important solvent associated with living things is ______.
Select one:
- carbon dioxide
- sodium chloride
- ethyl alcohol
- / 4