Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to:Explain the processes of digestion and absorptionCompare and contrast different types of digestive systemsExplain the specialized functions of the organs involved in processing food in the bodyDescribe the ways in which organs work together to digest food and absorb nutrients

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Past research has already tied our gut microbiome to many diseases. However, most research to date has focused on the large intestine, as collecting stool samples is less invasive than sampling the small intestine. Recently, researchers used standard-of-care endoscopies as an opportunity to collect samples from the first section of the small intestine, the duodenum. Using quantitative sequencing, they evaluated the patients' microbial loads. They found preliminary evidence of microbes traveling from the mouth to the small intestine, as 89% of the microbial taxa found in duodenum samples were also present in saliva samples from the same patient. Within the duodenum, the researchers identified a collection of bacterial taxa that, when present, often dominated the microbial population. These ‘disruptor taxa’ appeared to replace the strict anaerobes common in the duodenum and were more prevalent in individuals with the serious GI disorder small intestinal bacterial overgrowth (SIBO)..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

The duodenum is the proximal part of the small intestine and extends from the pylorus of the stomach to the jejunum. It has descending and ascending portions and both portions have digestive and absorptive functions.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Cost of feed is a major expense in chicken production, and that cost has been increasing due to overlap with human food and biofuel production. Therefore, improving feed efficiency can help reduce costs in chicken production systems. Both host genetics and gut microbiota can influence phenotypic traits like feed efficiency. New research explored this relationship in meat-type chickens by examining the host genetics as well as the microbiota from four intestinal regions and feces. Host relatedness showed little correlation to microbial community, but specific host genetic markers were associated with a small number of gut microbes. The greatest effect on feed efficiency, measured by residual feed intake (RFI), was host genetics. Out of the microbiota examined, only the cecum had a significant effect on the observed variance in RFI. Researchers also identified six bacterial groups associated with significant differences in feed efficiency..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.