An Si–O–Si linkage. hydrolysis produces silanol groups; their condensation can regenerate an Si–O–Si linkage.

Analytical ultracentrifugation observes concentration profiles during rotation, rather than only recovering a separated pellet. Sector-shaped sample cells rotate past optical detectors. Absorbance scans measure attenuation at selected radii. A Rayleigh interferometer compares a sample sector with a solvent reference, converting concentration-dependent refractive-index changes into fringe shifts. Repeating scans follows a sedimentation boundary or the approach to a stationary distribution.^[ref]

For a dilute solute of buoyant mass $m_b$ and translational friction $f_h$, radial force balance gives $s=m_b/f_h$, where $s$ is the sedimentation coefficient. Diffusion supplies $D=k_{B}T/f_h$. A velocity experiment resolves boundary motion and broadening; a sedimentation equilibrium experiment instead measures $d\ln c/d(r^2)=m_b{\omega }^2/(2k_{B}T)$. This follows from the Boltzmann distribution in centrifugal potential $-m_b{\omega }^2{r}^2/2$. The two approaches separate frictional size information from buoyant mass information; shape, hydration and solvent properties must be specified to infer a unique geometric dimension.

A discrete dynamical system with an ant moving on a colored square lattice. In its standard two-color form, the ant turns right on white, left on black, flips the current cell's color, and advances one cell. From an all-white board it eventually exhibits a repeating pattern that translates across the lattice.

Rule 90 is the binary one-dimensional cellular automaton whose update replaces each cell by the exclusive or of its two neighbors.

Plant genetics studies inherited variation and its transmission in plants. Alleles, chromosomes, meiosis and fertilization connect molecular differences to offspring genotypes and phenotypes. Self-fertilization, outcrossing and asexual reproduction produce different patterns of relatedness and genetic mixing.

A practical example is plant breeding: crossing two lines combines parental alleles, but genetic linkage can keep an unwanted variant close to a desired one. Distinguishing the causal variant from neighbouring markers is therefore essential when interpreting an inherited association.

A crop is a plant cultivated for a useful product, such as grain, fruit, fibre or oil. The term can denote the cultivated species, a particular planting or its harvested yield. A crop's useful performance depends on both inherited traits and the environment in which it is grown.

Improved photosynthesis need not produce the same yield benefit in every field: the limiting factor may instead be water, nutrients or reproductive development. Experiments that accelerated recovery from photoprotection in tobacco measured productivity under fluctuating light, connecting a leaf mechanism to a whole-plant outcome.^[ref]

Plant immunity is the set of recognition and response mechanisms by which plants restrict harmful interactions with other organisms. Surface pattern recognition receptors detect characteristic molecular patterns; intracellular nucleotide-binding leucine-rich repeat receptors can detect pathogen-associated activity. These routes interact rather than forming independent, universally sufficient barriers.

An integrated decoy illustrates how recognition can exploit an attacker's own activity: an immune receptor incorporates a structure resembling a target, so modification of that structure can trigger defence. The RRS1-RPS4 receptor pair is an experimentally studied example.^[ref]

Study of the functions of plants, including photosynthesis, transport, growth and signal transduction.

Production of useful molecules using photosynthesis to supply fixed carbon, energy or reducing power. Engineering a Cytochrome P450 at a photosynthetic membrane illustrates how an introduced biosynthetic reaction can draw on light-driven electron transfer.^[ref]

A compositionally enriched biomolecular assembly. Calling an assembly a condensate does not alone establish equilibrium liquid–liquid phase separation or a particular biological function.

In affinity purification-mass spectrometry, a bait protein is isolated with associated material, and mass spectrometry identifies candidate partners. Enrichment relative to matched controls supports association; it does not alone establish a direct protein-protein interaction or the number of copies per assembly.

co-immunoprecipitation captures a protein using an antibody and tests which other components remain associated. Reciprocal capture, input abundance and negative controls help interpret the result; coprecipitation need not imply direct contact.

proximity labeling uses a localized reactive system to mark nearby molecules before extraction. The recovered label integrates access, distance, labeling rate and residence time; proximity alone does not demonstrate a direct protein-protein interaction.

TurboID is an engineered promiscuous biotin ligase used for proximity labeling. A fusion can label nearby proteins during a short pulse, while localization-matched and no-added-biotin controls help distinguish the intended neighbourhood from background.^[ref]

single-particle tracking estimates successive positions of individual labeled objects. Displacements can constrain diffusion, confinement or directed movement, provided localization error, missed detections and label effects are accounted for.

colocalization is spatial coincidence of measured distributions within the resolution of an imaging method. Shared pixels can suggest a common compartment without demonstrating direct molecular contact.

double electron-electron resonance is a pulsed electron paramagnetic resonance method that uses spin–spin coupling to constrain distances between labels. Label conformation, distance distributions and background correction affect the structural interpretation.

radiation damage is a radiation-induced change in a specimen. In biological electron microscopy, accumulated exposure can alter chemical groups and remove high-resolution information, so recording more electrons has competing signal and damage effects.