PHUMA key terms

Idea central o asunto del que trata un texto, que se puede enunciar en una frase y se distingue de los temas secundarios que lo acompañan.

Postura o afirmación principal que el autor defiende en un texto argumentativo; suele aparecer en la introducción o el cierre y el resto del texto la sostiene.

Reformulación breve y fiel del contenido de un texto, con las ideas esenciales y sin opiniones ni detalles accesorios, respetando el orden lógico del original.

Propiedad textual por la que las ideas se organizan en torno a un tema con una progresión lógica, sin contradicciones ni saltos que rompan el sentido global.

Conjunto de mecanismos lingüísticos (conectores, pronombres, elipsis, repeticiones léxicas) que enlazan las oraciones y párrafos de un texto para que se lean como una unidad.

Palabra o locución que señala la relación lógica entre segmentos del texto: adición, contraste, causa, consecuencia, orden o ejemplificación, entre otras.

Unidad lingüística que guía la interpretación del discurso y organiza la conversación o el texto escrito, como 'en primer lugar', 'sin embargo' o 'por cierto'.

Reescritura de un enunciado o texto con otras palabras, conservando su significado esencial; puede ser explicativa, cuando aclara el contenido, o mecánica.

A symbol representing a quantity whose permitted values must follow the stated domain and the units of the problem rather than an unstated assumption.

The allowed inputs or values for a mathematical statement, including any restrictions from the context, a denominator, an even root or a count.

A claim that two expressions have equal values, whose solutions must make the original relation true and satisfy the declared restrictions.

A comparison describing values above or below a boundary, with inclusion or exclusion of the boundary indicated by the relation used.

A rule or relation assigning each permitted input exactly one output, distinguished from a general relation that may assign multiple outputs to one input.

The change in the vertical variable divided by the change in the horizontal variable between appropriate points on a nonvertical line.

A point where a graph meets a specified coordinate axis, whose interpretation depends on the variable definitions and whether that point belongs to the model domain.

A multiplicative component of an expression or integer, distinguished from a term separated by addition when deciding whether cancellation is valid.

Water chemical potential expressed relative to a defined pure-water reference, often in pressure units. Pure water at reference conditions is assigned zero; positive pressure can raise potential, and water moves toward lower potential.

The net movement of water across a partially permeable membrane from a region of higher water potential to one of lower water potential. It is passive and driven by the water potential gradient.

The component of water potential caused by dissolved solutes, always negative or zero. More concentrated solutions have more negative solute potentials and so attract water.

Shrinking of the protoplast away from the plant cell wall when a cell loses water in a hypertonic solution. It occurs because the protoplast contracts while the rigid wall stays in place.

Passive movement through membrane channels or carriers down an electrochemical gradient. The transport step does not directly hydrolyze ATP, although other processes may use energy to establish the gradient.

Energy-coupled movement against an electrochemical gradient. Primary transport can use ATP directly; secondary transport uses a gradient established by another energy-dependent process.

The description of membranes as a phospholipid bilayer with proteins and other molecules embedded in or attached to it, able to move laterally. It explains selective permeability and membrane flexibility.

The first stage of mitosis, when chromosomes condense, the nuclear envelope breaks down and spindle fibres begin to form. Each chromosome is already duplicated into two sister chromatids.