Question

There is an estimated 10-100 trillion bacteria and other microorganisms living in the human digestive system, forming a mutualistic relationship in which all species benefit. Recently, much research has been done on the role of these microorganisms in the development of disease, the brain, and behavior.

Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used.
The________ is a layer of cells lining the blood vessels within the brain, acting as a filter that controls the molecules that pass between the blood and the brain.
An organism's ________ is the collection of all the microorganisms (e.g. bacteria, phages, fungi) that live inside the digestive system of that individual.
A_______is a type of intercellular protein connection between animal cells that prevents leakage of materials through the space between the cells.
The transmembrane protein ________ is one of the component proteins of a tight junction.
________lack all microorganisms in their digestive systems, a state achieved by delivering them through cesarean section and raising them in sterile incubators.
_______ are raised under sterile conditions to limit their exposure disease-causing microorganisms.
tight junction
gut microbiota gap junction
germ-free mice pathogen-free mice
blood brain barrier adhesion plaque
occludin

Answer 1

- The blood brain barrier is a layer of cells lining the blood vessels within the brain, acting as a filter that controls the molecules that pass between the blood and the brain.

- An organism's gut microbiota is the collection of all the microorganisms (e.g. bacteria, phages, fungi) that live inside the digestive system of that individual.

- A gap junction is a type of intercellular protein connection between animal cells that prevents leakage of materials through the space between the cells.

- The transmembrane protein occludin is one of the component proteins of a tight junction.

- Germ-free mice lack all microorganisms in their digestive systems, a state achieved by delivering them through cesarean section and raising them in sterile incubators.

- Pathogen-free mice are raised under sterile conditions to limit their exposure disease-causing microorganisms.

Step-by-step explanation:

The blood-brain barrier is a layer of cells made up of endothelial cells that act to limit the passage of substances from the bloodstream in a more selective manner than endothelial cells of capillaries located in other parts of the body. Gut microbiota can be defined as all the microorganisms (i.e., bacteria) inhabiting the mammalian gastrointestinal tract, which helps to ferment non-digestible substrates (e.g., dietary fibers). A gap junction is a class of cell junction that is formed between cells contacting each other which allows small molecules (e.g., water, ions, metabolites, microRNA sequences, etc) to pass through this intercellular communication. In vertebrate animals, cell junctions can be divided into 1-gap junctions (communication between cells), 2-tight junctions (occludin junctions), and 3-adherens junctions, hemidesmosomes and desmosomes (anchor junctions). Tight Junctions are composed of multiple proteins including transmembrane proteins such as occludin, tricellulin, junctional adhesion molecule (JAM), and one member of the claudin protein family. Germfree animals are research animals that have no microorganisms living in or on them, which are housed in controlled/isolated conditions to prevent any type of contamination. Finally, pathogen-free animals are research animals that are guaranteed to be free of particular pathogenic (harmful) microorganisms.