QUESTIONS AND ANSWERS GRADED A+
✔✔Endotoxins - ✔✔are present inside the cell or can be the lipopolysaccharide
components of the outer membrane of some bacteria (Gram-negative). Importantly,
these toxins are only released upon the death of the bacterial cell when the cell wall
begins to decompose. An example of this phenomena is observed with the Salmonella
bacterial species that are responsible for food poisoning in humans.
✔✔decomposers - ✔✔break down dead and dying organisms and release vital
elements such as carbon, nitrogen, and phosphorous into the environment
✔✔symbiotic relationship - ✔✔a long-term relationship between two organisms in which
one or both organisms benefit from the paired interaction. may be mutualistic,
communalistic, or parasitic
✔✔Mutualism - ✔✔refers to a relationship where there is a mutual benefit to both
organisms. An example would be E. coli in the intestinal tract of humans. The non-
pathogenic E. coli competes with other bacteria and helps keep pathogenic bacteria
from inciting an infection. In return, the E. coli obtains adequate nutrients while living
within the host.
✔✔Commensalism - ✔✔occurs when only one of the symbionts benefits while the other
is unharmed or unaffected. An example of this relationship would be the bacteria that
live on the surface of our skin. The bacteria benefit by metabolizing oils and dead skin
cells, and the human really does not receive a benefit but also is not harmed through
the colonization of these bacteria.
✔✔Parasitism - ✔✔occurs when the symbiont harms the host while exploiting a benefit.
An example would be a pathogenic bacterium that colonizes its host and results in
damage to host tissues. Streptococcus A, or "Strep Throat" is an example of parasitism.
✔✔Eukaryotes can be divided into four main kingdoms - ✔✔(1) Fungi, (2) Protista, (3)
Plantae, and (4) Animalia.
✔✔Eukaryote Kingdoms: Fungi - ✔✔may be unicellular or multicellular and include
organisms such as yeasts, molds, rusts, mildews, and mushrooms.
✔✔heterotrophic - ✔✔they cannot manufacture their own food and must, therefore, take
in organic molecules to use as an energy source.
✔✔Hyphae - ✔✔After fertilization, fungi grow as thin, threadlike structures. consist of
tubular cell walls which surround the plasma membrane and cytoplasm of individual
fungal cells.
, ✔✔septa - ✔✔large pores that allow for the flow of cellular organelles such as
ribosomes, nuclei, and mitochondria from cell to cell.
✔✔haustoria - ✔✔which allows fungi to extract nutrients from plants.
✔✔mycotic infections - ✔✔Some pathogenic species can cause parasitic infections.
may be superficial such as Tinea pedis, "Athletes' Foot" or Tinea corporis "ring worm".
These types of infections are usually uncomplicated and easy to treat with antifungal
medications.
✔✔deep mycotic infections - ✔✔may be subcutaneous or systemic. Such infections are
serious threats to those with compromised immune systems, such as people suffering
from HIV or those undergoing intensive chemotherapy treatments
✔✔Histoplasmosis - ✔✔caused by inhalation of Histoplasma spores often found in bird
and bat droppings and results in Acute Respiratory Distress Syndrome (ARDS)
damaging delicate lung tissue and preventing proper oxygenation of blood.
✔✔Candidiasis - ✔✔can indeed be a superficial infection, but disseminated disease
may occur if a species, Candida albicans, gains access to the bloodstream and adheres
to internal body organs and tissues.
✔✔Eukaryotic Kingdoms: Protista - ✔✔exhibit a wide range of inter-kingdom variability.
For instance, while they are mostly unicellular, a small subset is classified as
multicellular.
✔✔Binary fission - ✔✔the process of reproduction where the parent body is seemingly
pinched into two halves, resulting in two daughter organisms each with its own nuclei.
✔✔contractile vacuole - ✔✔which is used to pump excess water from the cell
✔✔Plasmodium - ✔✔obligate parasites of vertebrates with a complex life cycle.
✔✔four species of Plasmodium that are responsible for causing Malaria infection in
humans - ✔✔P. falciparum, P. malariae, P. ovale and P. vivax.
✔✔Eukaryotic Kingdoms: Plantae - ✔✔Organisms of this kingdom are multicellular,
autotrophs which may be vascular or avascular. In addition to the presence or absence
of vascular tissue, plants may also be classified by the presence and absence of seeds.
✔✔Vascular plants - ✔✔have cells joined into tube like structures that allow for the
transport of water and nutrients throughout the plant body. Examples of vascular plants
are angiosperms (flowering plants), conifers, and ferns.