KEY TERMS - cells Flashcards
define control
control (experimental)
A yardstick against which experimental treatments are compared. A control should differ from a treatment in only onevariable, so any difference between the two can be attributed to that variable.
define replicate
In statistics, replication is repetition of an experiment or observation in the same or similar conditions. Replication is important because it adds information about the reliability of the conclusions or estimates to be drawn from the data.
define cell wall
cell wall
An external non-living, rigid structure enclosing the cell membrane of algal, plant, fungal and most prokaryotic cells. The primary constituent is cellulose (algae, plants and some fungi), chitin (some fungi) or polysaccharides (prokaryotes)
define cell membrane
the membrane surrounding the cytoplasm of a cell
define nucleus
An organelle enclosed within its own double membrane and containing the chromosomes.
define chromosomes
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
define ribosomes
ribosome
Cell organelles that translate the DNA code into a linear sequence of amino acids, which collectively form proteins. Free ribosomes occur in the cytoplasm of prokaryotic or eukaryotic cells, bound ribosomes are on the endoplasmic reticulum in eukaryotic cells.
define golgi complex
The Golgi apparatus is responsible for transporting, modifying, and packaging proteins and lipids into vesicles for delivery to targeted destinations. It is located in the cytoplasm
define lysosomes
lysosomes
Organelles arising from the rough endoplasmic reticulum and the Golgi apparatus, and containing enzymes that break down food particles and recycle damaged organelles. They also play a role in controlled cell death.
define mitochondria
Organelle that converts the chemical energy of organic molecules such as sugars into the chemical energy of the molecule ATP (adenosine triphosphate) that then powers work within the cell.
define vacuoles
a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid.
define centrioles
each of a pair of minute cylindrical organelles near the nucleus in animal cells, involved in the development of spindle fibres in cell division
define cilia
a short microscopic hairlike vibrating structure found in large numbers on the surface of certain cells, either causing currents in the surrounding fluid, or, in some protozoans and other small organisms, providing propulsion.
define flagella
a slender threadlike structure, especially a microscopic appendage that enables many protozoa, bacteria, spermatozoa, etc. to swim
define chloroplast
a plastid in green plant cells which contains chlorophyll and in which photosynthesis takes place
define mitosis
Cell division in eukaryotic cells where one cell gives rise to two daughter cells, each with the same chromosome number as the parent.
define meiosis
Meiosis
Cell division in eukaryotic cells where one cell gives rise to four haploid daughter cells, each with half the number of chromosomes of the parent.
define diffusion
diffusion
Passive movement of dissolved molecules or ions from a region of high concentration to a region of low concentration.
define osmosis
osmosis
Diffusion of water across a differentially-permeable membrane, which takes place from a region of greater water potential to one of lesser water potential
define photosynthesis
photosynthesis
The process in autotrophs by which solar energy is trapped in the chloroplasts and converted to chemical energy in the form of the bonds in ATP (adenosine triphosphate) molecules.
define respiration
Respiration is defined as a metabolic process wherein, the living cells of an organism obtains energy (in the form of ATP) by taking in oxygen and liberating carbon dioxide from the oxidation of complex organic substances.
