Biology Unit 1 Definitions

Front 1

Adaptation

Back 1

Special feature that makes an organism particularly well suited to the environment where it lives.

Front 2

Adult Cell Cloning

Back 2

Process in which the nucleus of an adult cell of one animal is fused with an empty egg from another animal. The embryo which results is placed inside the uterus of a third animal to develop.

Front 3

Antibiotic

Back 3

Drug that destroys bacteria inside the body without damaging human cells.

Front 4

Asexual Reproduction

Back 4

Reproduction that involves only one individual with no fusing of gametes to produce the offspring. The offspring are identical to the parent.

Front 5

Auxin

Back 5

A plant hormone that controls the responses of plants to light (phototropism) and to gravity (gravitropism).

Front 6

Bacteria

Back 6

Single-celled microorganisms that can reproduce very rapidly. Many bacteria are useful, for example, gut bacteria, but some cause disease.

Front 7

Biomass

Back 7

Biological material from living or recently living organisms.

Front 8

Carbon Cycle

Back 8

The cycling of carbon through the living and non-living world.

Front 9

Carnivore

Back 9

Animal that eats other animals.

Front 10

Central Nervous System (CNS)

Back 10

The central nervous system is made up of the brain and spinal cord where information is processed.

Front 11

Charles Darwin

Back 11

The Victorian scientist who developed the theory of evolution by a process of natural selection

Front 12

Chromosome

Back 12

Thread-like structure carrying the genetic information found in the nucleus of a cell.

Front 13

Clone

Back 13

Offspring produced by asexual reproduction that is identical to the parent organism.

Front 14

Combustion

Back 14

The process of burning.

Front 15

Competition

Back 15

The process by which living organisms compete with each other for limited resources such as food, light or reproductive partners

Front 16

Compost Heap

Back 16

A site where garden rubbish and kitchen waste are decomposed by microorganisms.

Front 17

Contraceptive Pill

Back 17

A pill containing female sex hormones which is used to prevent conception.

Front 18

Culture Medium

Back 18

A substance containing the nutrients needed for microorganisms to grow

Front 19

Decomposer/ Detritus Feeder

Back 19

Microorganism that breaks down waste products and dead bodies.

Front 20

Denature

Back 20

Change the shape of an enzyme so that it can no longer speed up a reaction.

Front 21

Depression

Back 21

A mental illness that involves feelings of great sadness that interfere with everyday life

Front 22

Double-Blind Trial

Back 22

A drug trial in which neither the patient nor the doctor knows if the patient is reiving the new drug or a placebo.

Front 23

Drug

Back 23

A chemical which causes changes in the body. Medical drugs cure disease or relieve symptoms. Recreational drugs alter the state of your mind and/or body.

Front 24

Effector organ

Back 24

Muscle and gland that responds to impulses from the nervous system.

Front 25

Enzyme

Back 25

Protein molecule that acts as a biological catalyst.

Front 26

Epidemic

Back 26

When more cases of an infectious disease are recorded than would normally be expected.

Front 27

Evolution

Back 27

The process of slow change in living organisms over long periods of time as those best adapted to survive breed successfully.

Front 28

Evolutionary Relationship

Back 28

Model of the evolutionary relationships between different organisms, often based on DNA evidence, which suggest how long ago the evolved away from each other and how closely related they are in evolutionary terms.

Front 29

Evolutionary Tree

Back 29

Model of the evolutionary relationships between different organisms based on their appearance, and increasingly, on DNA evidence.

Front 30

Extremophile

Back 30

Organism which lives in environments that are very extreme, for example, very high or very low temperatures, high salt levels or high pressures.

Front 31

FSH

Back 31

Follicle stimulating hormone, a female hormone that stimulates the eggs to mature in the ovaries, and the ovaries to produce hormones, including oestrogen.

Front 32

Gamete

Back 32

Sex cell that has half the chromosome number of ordinary cells.

Front 33

Gene

Back 33

A short section of DNA carrying genetic information.

Front 34

Genetic Engineering/ modification

Back 34

A technique for changing the genetic information of a cell.

Front 35

Gravitropism

Back 35

Response of a plant to the force of gravity controlled by auxin.

Front 36

Herbivore

Back 36

Animal that feeds on plants.

Front 37

Immune System

Back 37

The body system which recognises and destroys foreign cells or proteins such as invading pathogens

Front 38

Immunisation

Back 38

Giving a vaccine that allows immunity to develop without exposure to the disease itself.

Front 39

Impulse

Back 39

Electrical signal carried along the neurons.

Front 40

Indicator Species

Back 40

Lichens or insects that are particularly sensitive to pollution and so can be used to indicate changes in the environmental pollution levels.

Front 41

Infectious Disease

Back 41

Disease which can be passed from one individual to another.

Front 42

Inheritance of Acquired Characteristics

Back 42

Jean-Baptiste Lamarck’s theory of how evolution took place.

Front 43

Inherited

Back 43

Passed on from parents to their offspring through genes.

Front 44

Internal Environment

Back 44

The conditions inside the body.

Front 45

Jean-Baptiste Lamarck

Back 45

French biologist who developed a theory of evolution based on inheritance of acquired characteristics.

Front 46

Kidney

Back 46

Organ which filters the blood and removes urea, excess salts and water.

Front 47

Kingdom

Back 47

The highest group in the classification system, for example, animals, plants.

Front 48

Malnourished

Back 48

The condition when the body does not get a balanced diet.

Front 49

Mass

Back 49

The quantity of matter in an object; a measure of the difficulty of changing the motion of an object (in kilograms, kg)

Front 50

Menstrual Cycle

Back 50

The reproductive cycle in women controlled by hormones.

Front 51

Metabolic Rate

Back 51

The rate at which the reacts of your body take place, particularly cellular respiration.

Front 52

Microorganism

Back 52

Bacteria, viruses and other organisms that can only be seen by using a microscope.

Front 53

Motor Neuron

Back 53

Neuron that carries impulses from the central nervous system to the effector organs.

Front 54

MRSA

Back 54

Methicillin-resistant Staphylococcus aureus. An antibiotic-resistant bacterium.

Front 55

Mutation

Back 55

A change in the genetic material of an organism.

Front 56

Natural Classification System

Back 56

Classification system based on the similarities between different living organisms.

Front 57

Natural Selection

Back 57

The process by which evolution takes place. Organisms produce more offspring than the environment can support so only those which are most suited to their environment - the ‘fittest’ – will survive to breed and pass on their useful characteristics.

Front 58

Nerve

Back 58

Bundle of hundreds or even thousands of neurons.

Front 59

Neuron

Back 59

Basic cell of the nervous system which carries minute electrical impulses around the body.

Front 60

Obese

Back 60

Very overweight, with a BMI of over 30.

Front 61

Oestrogen

Back 61

Female sex hormone which stimulates the lining of the womb to build up in preparation for a pregnancy.

Front 62

Oral Contraceptive

Back 62

Hormone contraceptive that is taken by mouth.

Front 63

Organic Waste

Back 63

Waste material from living organisms, for example, garden waste.

Front 64

Ovary

Back 64

Female sex organ which contains the eggs and produces sex hormones during the menstrual cycle.

Front 65

Overweight

Back 65

A person is overweight if their body carries excess fat and their BMI is between 25 and 30.

Front 66

Ovipositor

Back 66

A pointed tube found in many female insects which is used to lay eggs.

Front 67

Ovulation

Back 67

The release of a mature egg from the ovary in the middle of the menstrual cycle.

Front 68

Pancreas

Back 68

An organ that produces the hormone insulin and many digestive enzymes.

Front 69

Pandemic

Back 69

When more cases of a disease are recorded then normal in a number of different countries.

Front 70

Pathogen

Back 70

Microorganism which causes disease.

Front 71

Phototropism

Back 71

The response of a plant to light, controlled by auxin.

Front 72

Pituitary Gland

Back 72

Small gland in the brain which produces a range of hormones controlling body functions.

Front 73

Placebo

Back 73

A substance used in clinical trials which does not contain any drug at all.

Front 74

Progesterone

Back 74

Female sex hormone used in the contraceptive pill.

Front 75

Pyramid of Biomass

Back 75

A model of the mass of biological material in the organisms at each level of a food chain.

Front 76

Receptor

Back 76

Special sensory cell that detects changes in the environment.

Front 77

Reflex

Back 77

Rapid automatic response of the nervous system that does not involve conscious thought.

Front 78

Reflex Arc

Back 78

The sense organ, sensory neuron, relay neuron, motor neuron and effector organ which bring about a reflex action.

Front 79

Secreting

Back 79

Releasing chemicals such as hormones or enzymes.

Front 80

Sense Organ

Back 80

Collection of special cells known as receptors which respond to changes in the surroundings (for example, eye, ear).

Front 81

Sensory Neuron

Back 81

Neuron which carries impulses from the sensory organs to the central nervous system.

Front 82

Sewage Treatment Plant

Back 82

A site where human waste is broken down using physical, chemical, and biological processes to produce environmentally safe treated wastewater

Front 83

Sexual Reproduction

Back 83

Reproduction that involves the joining (fusing) of male and female gametes, producing genetic variety in the offspring.

Front 84

Solar (Light) Energy

Back 84

Energy from the sun or other light source.

Front 85

Species

Back 85

A group of organisms with many features in common which can breed successfully to produce offspring.

Front 86

Statin

Back 86

Drug which lowers the blood cholesterol levels and improves the balance of HDLs to LDL.

Front 87

Steroid

Back 87

Drug that is used illegally by some athletes to build muscles and improve performance.

Front 88

Stimuli

Back 88

A change in the environment that is detected by sensory receptors.

Front 89

Stomata

Back 89

Openings in the leaves of plants (particularly the underside) which allow gases to enter and leave the leaf. They are opened and closed by the guard cells.

Front 90

Synapse

Back 90

The gap between neurons where the transmission of information is chemical rather than electrical.

Front 91

Territory

Back 91

An area where an animal live and feeds, which it may mark out or defend against other animals.

Front 92

Thalidomide

Back 92

A drug that caused deformities in the foetus when given to pregnant women to prevent morning sickness.

Front 93

Tissue Culture

Back 93

Using small groups of cells from a plant to make new plants.

Front 94

Urea

Back 94

The chemical produced by the breakdown of amino acids in the liver which is removed by the kidneys.

Front 95

Urine

Back 95

The liquid produced by the kidneys containing the metabolic waste product urea along with excess water and salts from the body.

Front 96

Vaccination

Back 96

Introducing small quantities of dead or inactive pathogens into the body to stimulate the white blood cells to produce antibodies that destroy the pathogens. This makes the person immune to the future infection.

Front 97

Vaccine

Back 97

The dead or inactive pathogen used in vaccination.

Front 98

Viruses

Back 98

Microorganism which takes over body cells and reproduces rapidly, causing disease.

Front 99

White Blood Cell

Back 99

Blood cell which is involved in the immune system of the body, engulfing bacteria, making antibodies and making antitoxins

Front 100

Withdrawal Symptom

Back 100

The symptom experiences by a drug addict when they do not get the drug to which they are addicted