DP Biology Vocabulary - 1.1 Introduction to cells

Cell theory

theory that states that all organisms are composed of cells, and that all cells come from pre-existing cells.

Centi-

metric prefix 1/100th or 1 × 10-2.

Coarse focus dial

used to initially focus a light microscope on a specimen.

Differentiation

the alteration of a cell's morphology and physiology through changes in gene expression.

Emergent property

a property of a system that emerges from the interaction of the elements of the system.

Gene expression

the synthesis of a functional gene product, often protein, but also rRNA, tRNA, or snRNA.

Growth

an increase in physical size.

Homeostasis

the process in which an organism regulates activities within cells and their bodies to keep conditions stable.

Magnification

ratio of image size to actual size.

Metabolism

the sum of all of the chemical reactions that occur within an organism or within a cell.

Micro-

metric prefix 1 × 10-6.

Milli-

metric prefix 1 × 10-3.

Nano-

metric prefix 1 × 10-9.

Objective lens

the part of the microscope that gathers light from the specimen and focuses it to produce a real image.

Paramecium

genus of single-celled ciliated organisms.

Reductionism

an approach to science that holds that a complex system can be best understood as the sum of its parts, and that variables can be studied in isolation.

Response

in behavioural science, the behaviour that is the consequence of a stimulus.

Scale bar

a means of visually indicating the magnification of an image.

Stargardt's disease

a degenerative eye disease that has been the target of stem cell research.

Stem cell

a relatively undifferentiated cell that can give rise to other types of cells and retains the ability to divide.

Surface area to volume ratio

a variable that decreases as cells grow, so that it sets a limit to the size of cells.

System

a level of organization that emerges due to the interaction of elements.

Tissue

a group of cells with a common function and structure.