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
define overharvesting and give an examples
humans removing more organisms than can be replaced by reproduction = unsustainable
eg, Atlantic cod
define introduction of foreign species to a habitat and give an example
non-native species are introduced to the habitat
eg, cane toad
define ecosystem
a unit containing the community of organisms and their environment, interacting together.
define habitat
an area where an organism lives
define population
all the members of the same species
define community
all populations of living organisms in a habitat
define biodiversity
number of different species that live in an area.
define bioaccumulation
build up of chemical in body (fat)
define biomagnification
concentration of chemical increases with each tropic level
define biodegradable
cannot break down
define biological control of pests
introduction of foreign species
define deforestation
mass clearing of forests
define aerobic respiration
chemical reaction in cells that use oxygen to break down nutrient molecules and to release energy
define anaerobic respiration
chemical reaction in cells that breaks down nutrient molecules to release energy without oxygen
define oxygen debt
the extra oxygen needed after exercise to break down lactic acid
define disaccharides, and eg
2 simple sugars, maltose sugar
define ventilation
-movement of air in and out of lungs by breathing movement
define gas exchange
-diffusion of oxygen and carbon dioxide in and out of an organism’s body
define polysaccharides, and eg
multiple sugar molecules bonded together, starch
define protein molecules
a long chain of amino acids
define a balance diet
a balanced diet include carbohydrates, lipids, protein, vitamins, minerals, fiber and water in the correct proportions to meet energy and specific dietary needs.
define micronutrients
nutrients need in small amounts
Define Basal Metabolic Rate (BMR)
energy consumed in 1 day by process required to stay alive
define macronutrients
nutrients needed in large amounts
define fibers
indigestible carbohydrates
define cellulose
-is an insoluble fiber in plant cells
define peristalsis
muscles contraction during digestion
define reducing sugars
maltose
define enzymes
protein that is involved in all metabolic reactions where they function as biological catalysts
define catalyst
a substance which increases rate of reaction without being used up in the reaction
define substrate
molecule which an enzyme acts on
define optimum temp
temp where enzyme activity is highest
define KE
-random movement energy by enzyme and substrate
-heat increases this
define successful collisions
-when enzyme and substrate bump into each other with sufficient energy for chemical reaction to take place
define denatured
-when enzyme’s active site changes shape permanently so that itis not complementary to substrate
-caused by high temp and extreme pH
define digestion
break down of food
define mechanical digestion
break down of food into smaller pieces without chemical change to the food molecules
define ingestion
taking of substances into the body
define chemical digestion
break down of large insoluble molecules into small soluble molecules
define absorption into bloodstream
movement of nutrients from the small intestine into the blood
define assimilation
uptake and use of nutrients by cells
define egestion
removal of undigested food from the body as faeces
define saliva
mixture of water, mucus and amylase
Define bolus
lump of food
define emulsification
-physical process that breaks down large fat droplets into small fat droplets to provide large surface area for fat digestion by lipase
define inheritance
transmission of genetic information from generation to generation
eg. eye colour, hair colour, height
define chromosome
-made of DNA which contains genetic info in the form of genes
eg.
-46 chromo. (23 pairs) in every nucleus - 23 from sperm, 23 from egg
-arranged in pairs
define gene
-a length of DNA that codes for a protein
-eg. brown eyed protein
define Allele
-an alternative version of a gene
-eg. brown eyed allele
define haploid nucleus
-nucleus containing a single set of chromo.
eg. gametes, pollen & ovaries
define diploid nucleus
-nucleus containing 2 sets of chromo.
eg. in all body cells (2n = 46 [in pairs])
define gametes
sex cells ( sperm & egg)
define zygote
-fertilized egg
define mitosis
-nuclear division giving rise to genetically identical cells
(diploid -> diploid)
define meiosis
reduction division in which the chromo. no. is halving from diploid to haploid resulting in genetically diff. cells
(need for sexual reproduction)
(haploid-> diploid -> haploid)
define genotype
genetic make up of an organism in terms of an allele present
(always in 2 symbols)
eg, BB, Bb, bb
define phenotype
observable features of an organism
(always in words)
eg, brown eyes, blue eyes, curly hair
define homozygous
having 2 identical alleles of a particular gene
eg, BB, bb
define heterozygous
having 2 alleles of a particular gene
eg, Bb
define pure bred
2 identical homozygous individuals breed tgt
eg, BB & BB, bb & bb
define not pure bred
2 heterozygous individuals will not pure breed
define dominant allele
allele that is expressed if it is in the genotype
(always first letter & capital)
define recessive allele
allele only expressed when there is no dominant allele in the gene
(always small letter)
define variation
differences btw individuals of the same species
define mutation & example
-a genetic change to the NA in a gene or chromo.
-cystic fibrosus, Albinism, hemophilia
define artificial selection
-choosing particular organisms with desired characteristics to breed tgt & continuing this process over many generations
define natural selection
process where individuals with advantageous features are more likely to survive, reproduce, and pass their alleles to the next gen.
