A sex chromosome whose non-recombining regions provide a predominantly paternal human genealogy. That genealogy does not trace all ancestors of an individual.

A chromosome-number state differing by individual chromosomes from an exact whole-set complement. It is distinct from a uniform change in the number of complete chromosome sets.

Examination of chromosome number and morphology. Resolution is insufficient for many small sequence changes, so a normal karyotype does not establish an unchanged genome.

A locus prone to abnormal gaps, undercondensation or breakage under specified cellular conditions. A cytological gap is not by itself proof of a DNA double-strand break.

Sequencing recovered DNA to map chromatin associated with a protein or modification. antibody specificity, fragment resolution and normalization constrain interpretation.

Production and regulation of functional RNAs and proteins from the chloroplast genome. The location of the regulated process and the genomic origin of its regulator are different properties.

Allyl chloroformate is $\mathrm{ClC}(\mathrm{O})\mathrm{OC}{\mathrm{H}}_2\mathrm{CH}=\mathrm{C}{\mathrm{H}}_2$. oxygen acylation of an enolate makes an allyl enol carbonate.

The peroxy-linked chlorine oxide $\mathrm{ClOOCl}$, often written $\mathrm{C}{\mathrm{l}}_2{\mathrm{O}}_2$ in a chlorine monoxide dimer cycle. Thermal return to two chlorine monoxide radicals competes with a photolytic pathway that ultimately yields two chlorine atoms. The formula alone should not be taken as specifying every possible dichlorine-dioxide isomer.

For dimer photodissociation frequency $J$ and competing thermal dissociation frequency $k_d[M]$, the successful branch fraction is $f=J/(J+k_d[M])$. With steady dimer abundance and rapid subsequent recycling, ozone destruction is $2f{k}_a[M][\mathrm{ClO}{]}^2$. The factor two counts ozone molecules consumed per productive dimer event.

The chlorine peroxide structure formed by association of two ClO radicals with collisional stabilization. Its low-temperature stability and photodissociation provide a route for catalytic ozone destruction. In a laboratory flow system, changing among three ClO precursors and examining infrared spectra helped distinguish the predominant ClOOCl product from an alternative ClOClO isomer. Product assignment and ultraviolet absorption support the proposed intermediate, but do not alone measure an entire atmospheric cycle's ozone-loss rate.^[ref]

Growth limited principally by transport of reactants to a surface, rather than their surface reaction rate.

Growth limited principally by surface reaction kinetics. Uniform substrate temperature and controlled reactant concentrations help obtain uniform thickness.

Deposition in which a plasma activates gaseous precursors, permitting film growth at reduced substrate temperature. Plasma damage, composition and surface chemistry still need control.

Cyclic film deposition using separated, ideally self-limiting surface reactions. Precursor saturation and purge steps help control conformality and thickness.

A chemical vapor deposition route in which catalyst particles form or travel in the gas stream rather than remaining on a macroscopic support. For carbon nanotubes, particle nucleation, tube growth and aggregation can occur in one flowing reactor. Product withdrawal becomes possible when the growing network is sufficiently connected.

Dependence of nuclear shielding and resonance frequency on molecular orientation relative to the magnetic field. Its modulation contributes to nuclear-spin relaxation.

The chemical-shift position around which a first-order multiplet is split. A labelled outer line is not generally the resonance centre.

Nuclei with the same resonance frequency in the specified environment. Equivalent chemical shifts do not automatically imply magnetic equivalence when couplings to other nuclei differ.

Collision theory estimates a gas-phase reaction rate by combining encounter frequency with energetic and geometrical requirements for reaction. For distinct hard spheres with contact separation $R$, the collision cross section is $\pi R^2$, and the mean relative speed is $\sqrt{8kT/(\pi \mu )}$. A reactive barrier and orientation restrictions reduce the fraction of collisions that react.