Which of the following is NOT considered a microorganism?

Mitochondria

What are the 5 main functions an organism must have in order to be considered a “living organism"?

Order, reproduction, energy, sensitivity, regulation

What functions are viruses missing that consider them to be a “non-living organism?”

Reproduction and energy

How do viruses fit into the domain of life

they dont

Antonie van Leeuwenhoek was the first to build the microscope, with a resolution 0.2 μm, in 1676. What kinds of organisms can you see with a 0.2 μm resolution?

Bacteria, 10-6 m (micrometer) & Viruses, 10-9 m (nanometers)

If you are in a lab looking at bacterial cells under a microscope with an ocular lens of 10x and with a 40X objective lens, what is the total magnification of the microscope field?

400x

In order to see bacterial cells underneath a microscope, scientists may have to prep samples with dye in order to see cell morphology and internal structures. However, some organisms already contain molecules that help us see them. What are some examples of these molecules?

Sulfur Photosynthetic pigments Fluorescent proteins

During times of nutrient deprivation, cells are found to get smaller in response to this. Why would cells want to decrease their cell size in a nutrient deficient state opposed to increasing their cell size?

volume increases faster

You are a student in the lab accessing your gram stain results from a soil sample that you collected from the campus pond. Upon looking into the microscope you see many purple clustered circular cells. What can you conclude from these results?

It is a gram positive cocci, which means it has a thick peptidoglycan layer

Gram negative bacteria are surrounded by two layers of _________, between which lies the cell wall. Fill in the blank

membrane

Many different organisms will produce a cell wall made out of various types of molecules in certain configurations. Based on the different types of cell walls we talked about in class, which type has the strongest structure in terms of rigidity and preventing cell lysis?

Peptidoglycan found in bacteria

Peptidoglycan is made of two different sugars—N-acetylglucosamine (G) and N-acetylmuramic acid (M), and has four different amino acid attachments. One chain (sugar backbone G-M-G-M) is connected via _______ and cross-links to another chain via _______.

Glycosidic bonds, peptide bonds

What components of bacterial cells differ from eukaryotic cells?

Circular DNA supercoiled in the nucleoid. External structures like flagellum and pili. Additional DNA from plasmids.

What components of eukaryotic cells differ from bacterial cells?

Organelles and intracellular membrane-bound compartments with specific functions. Linear DNA in the nucleus enclosed in a membrane Intracellular trafficking systems for proteins, nutrients, solutes, ect

Instead of having intracellular transport mechanisms, bacterial cells are able to move nutrients, molecules, ect. via ________?

diffusion

Bacteria have circular chromosomes that are compacted via supercoiling and Eukaryotes have linear chromosomes that are compacted via histone proteins.

true

Plasmids are “extrachromosomal” meaning that they contain extra DNA that bacteria can incorporate into their chromosomes to gain functions. What are some examples of functions bacteria can gain from plasmids?

Antibiotic resistance genes Genes for special metabolisms Virulence factors

When a bacterial cell is passing a plasmid over to another bacterial cell this process is done via _________?

Conjugation

In the central dogma of genetic information flow DNA is __________ to RNA and then __________ to protein

Transcribed, translated

The enzyme RNA polymerase is responsible for making a RNA transcript while using DNA a “blueprint”. Where in the DNA does RNA polymerase dock onto to start this process?

Promoter

What genetic components are found in eukaryotic cells but not in bacterial cells?

Introns and exons

Bacteria are able to encode for multiple genes in one mRNA polycistronic transcript. What is the area in the DNA called where this transcript is transcribed from?

Operon

In Bacteria and Eukarya, transcription and translation are a simultaneous process that happens in the cytoplasm

false

Quorum sensing is a mechanism that allows bacteria to sense how many bacteria are around them. Why would this be important for many bacterial species?

To form biofilms To exchange genetic material To activate certain genes

During times of nutrient exhaustion, bacteria may have an operon, or cluster of genes, that they can express to process alternative nutrients. This operon is expressed only in the presence of the alternative nutrients

false

Some species have to activate specific activator proteins or sensor kinases that trigger transcription of specific genes. Many species are only able to achieve this

In certain cell densities

What are the steps in order that are involved in biofilm formation?

Attachment, colonization, development, active dispersal

During attachment and colonization, what genes are NOT upregulated/downregulated in biofilm forming bacteria

Genes to produce polysaccharides are downregulated

Why are biofilms beneficial for many bacterial species

Receive a constant flow of nutrients Can exchange genetic material in close proximity to one another. Allows for a greater opportunity for opportunistic pathogens to thrive

While biofilm formation can be beneficial for the bacterial organisms, it can be extremely problematic in human settings such as hospitals. What is NOT a reason why biofilms may be problematic in a hospital setting?

Many different bacteria can be recruited in the biofilm which makes co-infections more common

During times of extreme stress, some bacteria are able to adapt by differentiating into a new cell type known as endospores with often completely different characteristics. This is a non-reversible process that is considered a survival mode for many bacterial species

false

Heterocysts are

special differentiated cells in some cyanobacteria filaments

The chemical reaction that turns N2 gas into ammonia is oxygen sensitive. What are some ways that heterocysts combat this in oxygen producing cyanobacteria?

They lack photosystem II that produces O2 gas.
They have a thickened cell wall to prevent the diffusion of O2 gas.

example of anabolism

Protein synthesis from amino acid polymerization

What kind of organisms will you most likely not find in soils

Coccolithophores

Planting legumes that have root nodule-forming bacteria can save farmers from purchasing fertilizers because the bacteria

are able to fix nitrogen in the root nodules of legumes

Decomposition in the soil is initiated by microorganisms that are

excreting exoenzymes for the hydrolysis of macromolecules.

The main primary producers in the surface ocean of tropical and subtropical latitudes are

cyanobacteria

Microbial mats in the surface sediments around deep sea hydrothermal vent systems are mainly composed of

lithoautotrophic Bacteria