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:Discuss how fertilization occursExplain how the embryo forms from the zygoteDiscuss the role of cleavage and gastrulation in animal development

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:

"Trophoblast cell invasion is tightly controlled during pregnancy, but aberrant invasion is associated with placental diseases such as preeclampsia. The protein EGF is known to exert a proinvasive effect on trophoblast cells through its receptor, EGFR, but the mechanism remains unclear. To learn more, researchers recently conducted in vitro studies on a human trophoblast cell line treated with EGF. They found that EGF reduced the expression and secretion of KISS1, a gene encoding the tumor metastasis-suppressing protein kisspeptin by activating the EGFR-mediated PI3K/AKT signaling pathway. EGF also downregulated ID3 expression, an effect that was required for EGF-mediated KISS1 suppression. Functional assays confirmed that EGF-induced KISS1 downregulation stimulated human trophoblast cell invasion and analyses of clinical samples revealed that patients with preeclampsia (PE) had reduced serum EGF levels and increased serum and placental KISS1 levels..."

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:

"Recurrent pregnancy loss – two or more losses before 24 weeks of pregnancy – affects 1-2% of pregnant women. Although some factors have been identified, in most cases the cause is unclear. Researchers are focusing on the critical balance between immune cells and the developing embryo at the maternal-fetal interface. Decidual natural killer (dNK) cells, immune cells in the uterus, must use inflammation to promote the formation of the placenta’s blood supply while also maintaining immune tolerance to prevent damaging the embryo. This delicate balance requires another cell type – trophoblasts, embryonic cells that develop into the placenta. Recently, researchers examining trophoblast-dNK crosstalk found that one important pathway was affected in patients experiencing recurrent pregnancy loss. Autophagy regulates degradation of damaged cells, clearing the way for healthy cells to form tissue..."

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