Bacteria
Name the common shapes of bacteria.
Rod, coccus, spiral
Are fungi eukaryotes or prokaryotes?
True or false: Algae are photosynthetic eukaryotes with a wide variety of shapes.
True! Algae produce food via photosynthesis and can take many different shapes and both sexual and sexual reproductive forms.
True or false: Gram negative bacteria are more resistant to antibiotics.
True! Gram negative bacteria have an outer membrane (LPS layer) that is harder for antibiotics to penetrate.
The fluorescent microscope uses _____ dyes that allow organisms to appear luminescent, or glow, with an ultraviolet light source.
Fluorescent dyes (also known as fluorochromes). Fluorescent microscopes are commonly used for fluorescent-antibody technique to detect pathogenic microbes.
Name the common arrangements of bacteria.
Pairs, chains, clusters
What are the most common forms of fungi?
Molds! Molds form visible masses called mycelia, which are composed of long filaments (hyphae) that branch and intertwine. Examples include cottony growths on bread or fruit.
Where can you find algae in the real world?
Algae are abundant in freshwater, saltwater, soil, and on some plants. Algae need sunlight, water, and CO2 to complete photosynthesis.
Which has a thick layer of peptidoglycan that allows them to retain staining?
Gram positive bacteria have a thick layer of peptidoglycan, allowing the microbe to retain the colored stain.
True or false: Confocal microscopes reconstruct 3-D images by illuminating a "slice" or plane of the organism.
True! Confocal microscopes use fluorochromes to emit light. One plane of the specimen is illuminated with a blue light that passes through the opposite side. Confocal microscopes are used with computers that scan and stack images to create a 3-D representation.
Bacteria are prokaryotic, meaning they lack a ____.
Nucleus! Prokaryotes lack membrane bound organelles.
True or false: Yeasts are multicellular.
False. Yeasts are unicellular organisms. An example of multicellular fungi are mushrooms.
True or false: Protozoa are multicellular eukaryotic microbes.
False! Protozoa are unicellular. They are eukaryotic. An example of a protozoa is an amoeba.
True or false: Staining emphasizes structures.
True! The contrast between the colorless microbes and dark background make it easier to look at under a microscope.
The electron microscope uses a beam of ____ instead of light to see tiny organisms, viruses, and organelles.
Electrons! This microscope has better resolution due to the use of electrons. Electrons have shorter wavelengths than visible light, making them better at seeing structures too small to be seen with light microscopes.
True or false: Some bacteria can produce their own food through photosynthesis.
True! Bacteria account for 30% of oxygen on Earth.
Do fungi reproduce sexually, asexually, or both?
Fungi reproduce both sexually and asexually (binary fission, budding).
True or false: Protozoa can be found in moist habitats, such as marine water and the soil. Some protozoa are parasitic, meaning they derive their nutrients from living hosts.
True! Protozoa can be photosynthetic, meaning they need sunlight, water, and CO2 to survive. They can also feed off living organisms. An example of a parasitic protozoa is Giardia.
True or false: Bacteria are slightly positively charged.
False! Bacteria are slightly negatively charged. Because the surface is negatively charged, the cell surface will repel staining. The glass will stain, but the cells do not. Bacteria shows up as clear spots against a dark background.
The transmission electron microscope does not capture light generated. Instead it captures what?
(Hint: Look at the name of the microscope.)
The TEM captures electrons bouncing off the organisms. Atoms on the surface of the organism eject electrons.
Bacteria are able to swim using an organelle called ____.
Flagella. These are corkscrew-like appendages that push and pull bacteria like propellers.
Fungal cell walls are composed of ____.
Chitin. Chitin is an essential part of the cell wall and septa structure.
Protozoa move by using ________.
Pseudopods (false feet), flagella, cilia. Any of these appendages are used for locomotion.
Name the steps to complete a gram stain.
Heat fix the smear
Crystal violet (primary stain)
Iodine (mordant)
Alcohol (decolorizer)
Safranin (secondary stain)
Explain the difference between resolution and magnification.
Resolution is the ability to distinguish fine detail and structure (distinguishing two objects from each other). Magnification is the ability to make small objects seem larger.