Cross section (geometry) of Earth at right. Cross-sections are often used in anatomy to illustrate the inner structure of an organ, as shown at left. A cross-section of a tree trunk, as shown at left, reveals growth rings that can be used to find the age of the tree and the temporal properties of its environment. Cross section (geometry) In geometry and science, a cross section is the non-empty intersection of a solid body in three-dimensional space with a plane, or the analog in higher-dimensional spaces. Cutting an object into slices creates many parallel cross sections. The boundary of a cross section in
Plant–fungus horizontal gene transfer ancient, they have been difficult to detect and remain relatively unknown. Plant–fungus interactions could play a part in a multi-horizontal gene transfer pathway among many other organisms. Fungus–plant-mediated horizontal gene transfer can occur via phagotrophic mechanisms (mediated by phagotrophic eukaryotes) and nonphagotropic mechanisms. Nonphagotrophic mechanisms have been seen in the transmission of transposable elements, plastid-derived endosymbiotic gene transfer, prokaryote-derived gene transfer, "Agrobacterium tumefaciens"-mediated DNA transfer, cross-species hybridization events, and gene transfer between mitochondrial genes. Horizontal gene transfer could bypass eukaryotic barrier features like linear chromatin-based chromosomes, intron–exon gene structures, and the nuclear envelope. Horizontal gene transfer occurs between microorganisms sharing