definitions Flashcards
define Movement
an action done by an organism causing a change in position or place
Define Reproduction
process that makes more of the same kind of organism
define Sensitivity
the ability to detect and respond to changes in the internal and external environment
define Growth
permanent increase in size and dry mass
define Respiration
a chemical process where nutrients molecules are broken down and release energy for metabolism
define Excretion
removal of waste products for metabolism and substances in excess of requirement
note: needs to enter cells
Define Nutrition
taking in of materials for energy, growth and development
Define heterotrophic
organisms that eat other organisms
eg, animals
define generation time
time taken for each cell to divide into 2
define autotrophic
organisms that self feed
eg, plants
state the 3 cell theory
- all organisms are made up of 1 or more cells
- the cell is the basic organizational (smallest unit of life) unit of life
- all cells come from pre-existing cells
define cell
basic fundamental and structural unit in a living organism
define tissue
a group of cells of similar structure working together to perform the same functions
define organ
made form different tissues working together to perform specific functions
define organ system
group of organs with their related functions working together to perform bodily functions
define organism
a complex living thing made up of interacting organ systems
define diffusion
movement of particles from a region of higher concentration to the region of lower concentration down the concentration gradient as a result of their random movement
define concentration gradient
difference in region of higher concentration and a region of lower concentration
define osmosis
net movement of water molecules from a region of higher water potential to a region of lower water potential down a concentration gradient through a partially permeable cell membrane
define solute
substance dissolved in a solvent
define solvent
substance that a solute dissolves in
define solution
solute + solvent
define concentrated solution
high solute concentrated
define diluted solution
low solute concentration
define partially permeable cell membrane
a cell membrane that allows some substances through but not others
define net movement
total movement
define equilibrium
no net movement
define isotonic, hypertonic, hypotonic
-isotonic - equal solute concentration = equal water potential
- hypertonic - higher solute concentration - lower water potential
- hypotonic - lower solute concentration - higher water potential
define plasmolysis
cytoplasm and cell membrane rips away from the cell wall
define haemolysis
cell membrane bursts
define crenation
cell membrane shrinks
define passive
does not require cells energy from respiration
define active transport
movement of particles through a cell membrane from a region of lower concentration to the region of higher concentration up a concentration gradient using energy from respiration
define the sun
Sun is the principal source of energy input into biological systems
define food chains
shows transfer of energy from 1 organism to the next beginning with a producer
define trophic level
the position of an organism in a food chain/ web
define food webs
a network of interconnected food chains
define producer
an organism that make sit own organic nutrients usually using energy from the sunlight through photosynthesis (1 trophic level)
define consumer
an organism that gets it energy by feeding on other organisms
define predator
an organism at the top of the food chain/web and are not killed by other organisms
define herbivore
an animal that gets its energy only from plants
define carnivore
an animal that gets its energy by eating other organisms
define primary consumer
organism that feeds on a producer
define secondary consumer
organism that feeds on a primary consumer
define tertiary consumer
organism that feeds on a secondary consumer
define quaternary consumer
organism that feeds on a tertiary consumer
define decomposers
an organism that gets its energy from dead or waste organic material
define hydrolysis reaction
chemical break down of a compound due to reaction with water