Probiotics MCB6424 Exam 3 Questions with Complete Solutions (Latest 2025) microbiota vs microbiome - Correct Answers ✅microbiota - organisms microbiome - organisms + genes + genome The gut microbiota contains more than __ cells more than __ species - Correct Answers ✅200 trillion cells >1000 species The microbiome contains __x the cells in the human body The gut microbiome is __x larger than the human genome - Correct Answers ✅10x cells 150x genome Who came up with the official definition of microbiota? - Correct Answers ✅Lederberg and McCray, 2001 Microbiota definition - Correct Answers ✅"Ecological community of commensal, symbiotic, and pathogenic microorganisms within a body space or other environment" True/False the microbiome is generally non-pathogenic and beneficial to the host - Correct Answers ✅true Transient microbiota - Correct Answers ✅microbes that are present for various periods and then disappear 1 / 3
Probiotics MCB6424 Exam 3 Questions with Complete Solutions (Latest 2025) Although these types of organisms may colonize a host and reproduce briefly, the defenses of the body do not allow them to become permanent.
- types of Symbiosis - Correct Answers ✅mutualism,
commensalism, parasitism Commensalism - Correct Answers ✅one organism benefits
the other and the other is unaffected (ex: mycobacteria in the
ear)
mutualism - Correct Answers ✅both organisms benefit (ex:
- coli in the colon, synthesizes vit K)
parasitism - Correct Answers ✅one benefits at the expense
of the other (ex: disease causing bacteria)
___ plays a fundamental role in immune maturation - complete absence of bacteria in the gut results in ___ and low levels of ____ - Correct Answers ✅mutualism results in gut-associated mesenteric lymph tissue low levels IgA 2 / 3
Probiotics MCB6424 Exam 3 Questions with Complete Solutions (Latest 2025) Specific functions of the microbiota - Correct Answers ✅seal body spaces, mitigate intestinal pathogens, maintain tissue homeostasis, facilitate fermentation of dietary fiber (pectin, etc), critical energy yield, metabolic end products and therapeutic drug processing, signaling among cells and organ systems (butyrate - energy for gut epithelial cells; acetate and propionate - lipogenesis and methods to study the microbiota - Correct Answers ✅16S rRNA gene sequencing-based surveys and shotgun metagenomic approach 16S rRNA gene sequencing-based surveys - Correct Answers ✅Gene contains highly conserved regions and variable regions amplify 16S rRNA genes using primers directed at conserved regions but flanking variable regions align gene sequences, resolve phylogenetic relationships at different depths Most 16S rRNA sequences come from previously ____ - Correct Answers ✅undescribed microbes Operational Taxonomic Units - Correct Answers ✅a definition used to classify groups of closely related individuals Sequences are clustered according to their similarity to one another
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