1.1 introduction to cells vocab Flashcards
Objective lens
The part of the microscope that gathers light from the specimen and focuses it to produce a real image.
Coarse focus dial
This is used to initially focus a light microscope on a specimen.
Scale bar
A means of visually indicating the magnification of an image.
Magnification
The ratio of image size to actual size.
Cell theory
The theory that states that all organisms are composed of cells, cells are the smallest unit of life, and that all cells come from pre-existing cells.
Somatic cells
Any cell of a living organism other than the reproductive cells [ie body cells, not sperm or egg]
System
A level of organization that emerges due to the interaction of elements.
Tissue
A group of cells with a common function and structure.
Surface area to volume ratio
A variable that decreases as cells grow, so that it sets a limit to the size of cells.
Homeostasis
The maintenance of a constant internal environment by regulating internal cell conditions.
Metabolism
The web of all the enzyme catalysed reactions in a cell or organism.
Response
A reaction by the living organism to changes in the external environment.
Growth
An increase in physical size because of increasing in cell size or number of cells.
Paramecium
A genus of single-celled ciliated organisms.
Chlamydomonas
A unicellular algae that lives in soil and freshwater habitats. It is not a plant as its cell wall is not made of cellulose.
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.
Emergent property
A property of a system that emerges from the interaction of the elements of the system.
Differentiation
This involves the expression of some genes and not others in a cell’s genome.
Gene expression
The synthesis of a functional gene product, often protein, but also rRNA, tRNA, or snRNA.
Leukemia
Cancer of the blood or bone marrow, resulting in abnormally high levels of poorly-functioning white blood cells.
Stargardt’s disease
A genetic 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.
ESC
An abbreviation for Embryonic Stem Cells.
Specially created embryos
Embryos which are deliberated created by mixing sperm and egg and allowing the resulting zygote to develop for a few days. All the resulting cells are embryonic stem cells.
Cord blood stem cells
Stem cells obtained [and then frozen] from the umbilical cord of a new-born baby for later use in life for any blood diseases.
Genome
The complete set of genes, chromosomes or genetic material present in a cell or organism.
Totipotent
Stem cells that can differentiate into any type of cell.
Pluripotent
Stem cells that can differentiate into many types of cell.
Multipotent
Stem cells that can differentiate into a few closely-related types of cells.
Unipotent
Stem cells that can regenerate but can only differentiate into their associated cell type eg liver stem cells can only make liver cells.
