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:Describe the structure of eukaryotic cellsCompare animal cells with plant cellsState the role of the plasma membraneSummarize the functions of the major cell organelles

By the end of this section, you will be able to:Describe the cytoskeletonCompare the roles of microfilaments, intermediate filaments, and microtubulesCompare and contrast cilia and flagellaSummarize the differences among the components of prokaryotic cells, animal cells, and plant cells

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:

"Migrasomes are newly discovered extracellular vesicles that can mediate communication between cells. These unique vesicles form exclusively at the rear of migrating cells with the help of a protein called TSPAN4. After they’re left behind, the migrasomes and their contents can be captured by nearby cells and affect the recipient cells’ behavior. They can also serve as “breadcrumb trails” that mark the paths of their migrating parent cells. Migrasomes participate in both health and disease. For example, they can dispose of damaged mitochondria to maintain healthy cells and they help establish left–right patterning in zebrafish embryos by releasing the protein CXCL12 to recruit dorsal forerunner cells (DFCs). However, migrasomes can also deliver molecules that promote tumor growth and metastasis and migrasomes released from platelets promote blood clotting after SARS-CoV-2 infection..."

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

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:

"Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer. One of the distinguishing features of HCC tumors is their dense network of blood vessels. This makes Angiopoetin-2, a protein that promotes vessel formation in tumors, an attractive target for fighting HCC. In a recent study, researchers discovered a novel route HCC tumors use to release Angiopoetin-2. Test-tube experiments revealed that tumor cells wrapped Angiopoetin-2 in tiny sacs called exosomes. and delivered them to cells derived from human umbilical cord, which boosted blood vessel formation. Gene editing allowed the team to knock out the gene controlling Angiopoetin-2, which, once delivered, significantly reduced the generation of new lifelines from healthy cells. The results point to a new way of disrupting tumor growth. and could lead to new therapies for cancer of the liver and other organs..."

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

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:

"Sepsis is a life-threatening overreaction of the immune system to infection. Sepsis causes damage to vascular endothelial cells, which play an important role in maintaining vascular function. Treatment strategies that restore vascular endothelial cell function after sepsis are desperately needed. Pericyte-derived microvesicles (PMVs) have had therapeutic effects in other disorders and may be useful in sepsis treatment. To evaluate the potential treatment utility of PMVs, researchers combined experiments in rats and cultured vascular endothelial cells. PMVs were able to protect lung tissue and improve pulmonary function of septic rats. PMVs were also protective of cellular function in the cell culture model. Through subsequent experiments, the researchers determined that PMV absorption was mediated by the cell-surface protein CD44. and that PMVs restored vascular function by delivering the signaling molecule CTGF and activating the ERK1/2- STAT3 pathway..."

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

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:

"Extracellular vesicles (EVs) are small membrane-bound structures released by cells into the surrounding environment. EVs carry various biomolecules including proteins, DNA, RNA, and lipids and play critical roles in intercellular communication, including influencing the behavior and function of recipient cells. EVs have great potential in the clinical environment as diagnostic markers, treatment delivery vehicles, or therapeutic targets. However, to best utilize them researchers need to understand the mechanisms influencing EVs. Significant progress has been made in understanding the factors that regulate communication between cells via EVs, but there is still much to learn about what regulates EV targeting and uptake by recipient cells. Also, little is currently known about cargo release and relocation within the recipient cell. This is due to the extremely small size of EVs and a lack of imaging technology to visualize them..."

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

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:

"Exosomes are extracellular vesicles that can be transferred from cancer cells to surrounding cells in the tumor microenvironment. Despite their tiny size, exosomes have a huge effect on cell-to-cell communication, facilitating tumor progression and contributing to metastasis. Their widespread effects have drawn the attention of scientists hoping to develop new cancer therapies. A recent study focused on a specific type of exosome cargo – microRNAs (miRNAs), which can act as nucleic acid messengers between cells. Certain miRNAs are known to be enriched in cancer cell exosomes, but how this enrichment occurs is unclear. Using a pancreatic cancer cell line, researchers identified RNA-binding proteins that could bind to a common cancer-associated miRNA, miR-1246. They found that the protein SRSF1 could bind strongly with miR-1246. Reducing SRSF1 expression decreased the enrichment of miRNAs in exosomes, while overexpressing SRSF1 enhanced the enrichment..."

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