all bio defs

1st trophic level

first feeding stage in a food chain. Organism is known as producer.

2nd trophic level

second feeding stage in a food chain. Organism is known as primary consumer.

3rd trophic level

third feeding stage in a food chain. Organism is known as secondary consumer.

Abiotic factors

non-living factors that affect population size of a plant or animal in an ecosystem e.g. soil pH.

Active site

the location/part of the enzyme that reacts with the substrate.

Active transport

molecules move from an area of low concentration to an area of high concentration through a selectively permeable membrane, requiring energy or movement of molecules against a concentration gradient.

Active immunity

when the living organism produces the antibodies itself.

Active

a process that requires energy.

Adhesion

attraction of water molecules to the walls of the xylem vessels.

Aerobic respiration

the release of energy from food in the presence of oxygen.

Alleles

alternative forms of a gene e.g. Bb.

Amino acid

single protein subunit.

Anabolic reaction (anabolism)

small molecules are converted into large molecules and energy is required e.g.; photosynthesis.

Anaerobic respiration

the release of energy from food in the absence of oxygen.

Antagonistic muscle pairs

two muscles that work together but in opposite direction as muscles can only contract.

Antibiotic resistance

bacteria do not die in the presence of an antibiotic due to misuse or overuse of antibiotics.

Antibiotics

artificial antibodies produced by microorganisms used to treat infections by killing other microorganisms.

Antibody

a protein produced by B cells in response to an antigen being detected by helper T cells. Antibody is specific to antigen.

Antigen

a foreign particle that should not be found in a living organism e.g. dust, pollen, micro organisms. Will stimulate the production of antibodies.

Aquatic factors

water factors that affect population size of a plant or animal in an ecosystem.

Asexual reproduction

production of offspring where one parent (cell) involved.

Asepsis

free from all harmful microorganisms.

Assimilation

transfer of food from one location to another e.g.; blood to cells, transfer of protein from plants to animals in the nitrogen cycle.

ATP

adenosine (adenine (nitrogen) and ribose (sugar)) triphosphate. High energy molecule. Made from adenosine diphosphate (ADP) and phosphate (p). energy stored in 3rd phosphate bond.

Autoimmune disorder

human defence system attacks its own self (healthy tissue in human body).

Autotroph

a living organism that can make its own food.

Balanced diet

correct amount from each level in the food pyramid.

Binary fission

asexual reproduction in bacteria.

Bi-nuclear cell

cell containing two nuclei e.g. pollen grain has a generative nuclei and a tube nuclei.

Biochemical reaction

chemical reactions that takes place in a living organism.

Biodiversity

Variety of life in an ecosystem.

Bioprocessing

an industry that is involved in making products using living micro organisms and/or enzymes.

Bioreactor

a vessel/container in which a biochemical reaction involving microorganisms occurs.

Biosphere

part of planet where life is found.

Biotic factors

living factors that affect population size of a plant or animal in an ecosystem.

Blood pressure

force require to stop blood flowing in an artery; average = 120/80 mmHg. Measured in the upper left arm.

Breathing

physical act of taking in oxygen from the air and releasing carbon dioxide. Known as external respiration.

Budding

asexual reproduction in yeast (fungi).

Cancer

a cell loses control of the rate of mitosis.

Cardiac muscle

involuntary muscle that never fatigues.

Carnivore

flesh eating animal.

Catabolic reaction (catabolism)

large molecules are converted into small molecules and energy is released e.g.; respiration.

Cell continuity

living cells arise from other pre-existing living cells of the same type due to cell division.

Chemical digestion

use of chemicals such as enzymes and acid to break down food.

Chemosynthetic

a living organism ability to make its own food in the presence of chemicals e.g.; rhizobium.

Climate

long term weather.

Coding DNA

contains genes which instruction for the production of a protein.

Cohesion

attraction of water molecules to each other.

Combustion

burning of fossil fuels in the presence of oxygen.

Community

group of animals or plants sharing resources in an ecosystem.

Competition

struggle between organisms for a resource in limited supply.

Conservation

wise management of organisms to maintain biodiversity and prevent extinction of a species.

Contest competition

struggle between organism for a resource in limited supply and only one wins the resource e.g. a fox and a badger fighting over a rabbit and only one will get the rabbit.

Continuity of life

organisms arise from other organisms of the same type due to cell division.

Contraception

prevention of pregnancy by preventing fertilisation or implantation.

Contractile muscle

muscle/tissue that has the ability to shorten.

Control

for comparison with the experimental results.

Cotyledon

seed leaf that has the role of food storage.

Cross pollination

transfer of pollen from the male part of one plant (stamen) to the female part of another plant (carpel) of the same species.

Cytosol

cytoplasm without cell organelles.

Deamination

excess amino acids are converted to urea in the liver.

Decomposition

break down of dead organic matter. Performed by decomposers; (aka decomposing micro-organisms). Different decomposers break down different types of organic matter. Some micro-organisms break down protein while others break down carbohydrates.

Denaturation

an enzyme that has lost its 3D, folded, globular shape at the active site location and no longer is able to carry out its function; caused due to heating to a temperature above 60oC or exposure to extreme of pH away from optimum.

Denitrification

conversion of nitrates to atmospheric nitrogen (nitrogen gas). Performed by denitrifying bacteria.

Dermal tissue

type of tissue that provides protection.

Diastole

relaxation of the muscle walls of the heart.

Dicotyledon

two seed leaves.

Diffusion

movement of molecules from an area of high molecule concentration to an area of low molecule concentration across a selectively permeable membrane e.g.; gaseous exchange at the alveoli.

Digestion

breaking down of food into smaller parts primarily its subunits so that it can be transferred into the blood and cells faster and easier; achieved by physical and chemical means.

Dihybrid linked cross

a cross that involves the analysis of two traits being passed from one generation to the next that are located on the same set of chromosome.

Dihybrid non-linked cross

a cross the involves the analysis of passing down two traits that are located on different chromosomes.

Diploid

2 sets of chromosomes or chromosomes that appear in pairs.

Disaccharide

two sugar units joined together e.g. maltose.

Dispersal

Scattering/moving a seed from one location to another to avoid competition with parent plant or other plants.

DNA Profiling

Breaking DNA up into bands or fragments based on size for comparison purposes.

DNA replication

Making an exact copy of DNA.

DNA

Deoxyribo (deoxyribose- 6C sugar) Nucleic Acid.

Dominant

Trait which is most likely to be expressed in the next generation.

Dormancy

Period of low metabolism in a seed when conditions for growth are unfavorable which allows an embryo in the seed to mature and survive unfavorable conditions.

Double fertilisation

One haploid generative nuclei joins with haploid egg to form a diploid zygote. One haploid generative nuclei joins with 2 haploid polar nuclei to form a triploid endosperm.

Double-blind testing

Neither the tester nor the patient knows who is getting the real/active drug and who is getting the placebo. Helps to reduce bias.

Ecology

Study of the relationship between living organisms and their environment.

Ecosystem

A group of plants and animals sharing resources and interacting with their environment.

Ectoparasite

Lives on the surface of the host tissue/host cell.

Ectotherm

An animal that cannot maintain its own internal body temperature. Body temperature is influenced by its surroundings.

Edaphic factors

Soil factors that affect population size of a plant or animal in an ecosystem.

Egestion

Removal of undigested food waste from the human body.

Ejaculation

Release of semen (sperm and seminal fluid) at the cervix of female reproductive system.

Embryo

Develops from the zygote when it undergoes mitosis.

Endocrine gland

Ductless glands and secretes/produces hormones.

Endoparasite

Lives inside the host tissue/host cell.

Endospermic Seed

A seed that has an endosperm; may also have a cotyledon.

Endospore

A hard protective coat/shell formed within the structure of a bacterial cell when conditions for growth are unfavorable.

Endotherm

An animal that has the ability to maintain a constant internal body temperature and most of their heat is obtained from metabolism.

Enzyme

Biological catalyst made of protein that speeds up or slows down the rate of reaction without the enzyme being used up or change.

Ethics

A person's morals which influences their actions.

Eukaryote

A living organism that has a nucleus and membrane enclosed cell organelles e.g.; fungi.

Eutrophication

Removal of oxygen from water.

Excretion

Removal of waste products of metabolism from a living organism.

Exine

Outer protective layer of a pollen grain.