whorl. / (wɜːl) / noun. botany a radial arrangement of three or more petals, stamens, leaves, etc, around a stem. zoology a single turn in a spiral shell.
Carnegie stages are a system used by embryologists to describe the apparent maturity of embryos. An embryo is assigned a Carnegie stage (numbered from 1 to 23) based on its external features. This staging system is not dependent on the chronological age nor the size of the embryo.
The two-domain system defines classification of all known cellular life forms into two domains: Bacteria and Archaea. It overrides the domain Eukaryota recognised in the three-domain classification as one of the main domains.
synthetic language, any language in which syntactic relations within sentences are expressed by inflection (the change in the form of a word that indicates distinctions of tense, person, gender, number, mood, voice, and case) or by agglutination (word formation by means of morpheme, or word unit, clustering).
The spine apparatus corresponds to smooth endoplasmic reticulum (Spacek and Harris, 1997) which forms a widespread network in dendrites and spines (Cooney et al., 2002) and might play a role in the regulation of calcium movements and/or local protein synthesis.
Solid-phase reversible immobilization, or SPRI, is a method of purifying nucleic acids from solution. It uses silica- or carboxyl-coated paramagnetic beads, which reversibly bind to nucleic acids in the presence of polyethylene glycol and a salt.
Somatic DNA mutation analysis requires tumour tissue to source DNA which should be extracted from a relatively pure population of tumour cells and without significant necrosis or inflammation. Surgical resection specimens are generally straightforward since tumour-rich regions are more easily located.
In humans, visible secondary sex characteristics include enlarged breasts and widened hips of females, facial hair and Adam’s apples on males, and pubic hair on both.
Kew is governed by a board of trustees which comprises a chairman and eleven members. Ten members and the chairman are appointed by the Secretary of State for Environment, Food and Rural Affairs. Her Majesty the Queen appoints her own trustee on the recommendation of the Secretary of State.
Sex allocation is defined as the distribution of an organism’s resources to male versus female function (Warner, 1988).