Biology Keywords Flashcards
1
Q
Diffusion
A
The spreading out of the particles of any substance in a solution, or particles in a gas, resulting in a net movement of particles from an area of higher concentration to an area of lower concentration down a concentration gradient
2
Q
Hybridomas
A
Cells created during the production of monoclonal antibodies by the fusion of an antibody-specific lymphocyte and a tumour cell
3
Q
Resolving power
A
A measure of the ability to distinguish between two separate points that are very close together
4
Q
Coronary arteries
A
The blood vessels that supply oxygenated blood to the heart muscle
5
Q
Nucleotide
A
A molecule made up of a sugar, a phosphate group, and one of four different bases. They are key units in the structure of DNA and RNA
6
Q
Phototropism
A
The response of a plant to light, controlled by auxin
7
Q
Ciliary muscles
A
Muscles that contract and relax to change the shape of the lens of the eye
8
Q
Phenotype
A
The physical appearance biochemistry of an individual for a particular characteristic (e.g. blue eyes)
9
Q
Primary consumer
A
Animals that eat producers
10
Q
Mitosis
A
Part of the cell cycle where one set of new chromosomes is pulled to each end of the cell forming two identical nuclei during cell division
11
Q
Range
A
The maximum and minimum values for the independent or dependent variables - important in ensuring that any patterns are detected
12
Q
Mean average
A
The arithmetical average of a series of numbers (add together all valid results and divide by the number of results)
13
Q
Genotype
A
The genetic makeup of an individual for a particular characteristic, for example hair or eye colour (the allele combination e.g. BB, or Bb)
14
Q
Proteins
A
Molecules made of long chains of amino acids folded into specific shapes. They are used for building the cells and tissues of the body and to form substances such as enzymes
15
Q
Distribution
A
Where particular types of organisms are found within an environment
16
Q
STD / STI (Sexually transmitted disease / infection)
A
Transmitted from an infected person to an uninfected person by unprotected sexual contact / exchange of bodily fluids
17
Q
Culture medium
A
A liquid or gel used to support the growth of microorganisms or other cultures, often containing specific nutrients.
18
Q
Hyperopia
A
Long sightedness, where the rays of light from distant objects can be focused clearly on the retina but the rays of light from close objects are not focused and the objects appear blurred
19
Q
Contraception
A
Methods of preventing pregnancy which usually involve preventing the sperm and egg from meeting
20
Q
Preclinical testing
A
Is carried out on a potential new medicine in a laboratory using cells, tissues, and live animals to determine the drug’s potential
21
Q
Adult Stem cells
A
Partially differentiated stem cells that are found in adults that can form a limited number of cell types
22
Q
Coordination centres
A
Areas of the central nervous system that receive and process information from receptors
23
Q
Cerebral cortex
A
Region of the brain associated with consciousness, memory, and language
24
Q
Turgor
A
The pressure inside a plant cell exerted by the cell contents pressing on the cell wall
25
Myopia
Short sightedness, where the rays of light from close objects are brought into focus on the retina but distant objects appear blurred as the light is focused in front of the retina
26
Translocation
The movement of sugars from the leaves to the rest of the plant through the phloem
27
Catalyst
A substance that speeds up the rate of another reaction but is not used up or changed itself. The catalyst provides an alternative pathway for the reaction, which requires a lower activation energy
28
Anaerobic respiration
An exothermic reaction in which glucose is broken down without using oxygen to release a small amount of energy for the cell. In animals lactic acid is produced as a waste product. In plants and microorganisms ethanol and carbon dioxide are produced.
29
Quadrat
A piece of equipment used to measure the abundance and distribution of organisms in the field
30
Arteries
Blood vessels that carry blood away from the heart. They usually carry oxygenated blood (except the Pulmonary artery) and have a pulse
31
Sexual reproduction
Involves the joining (fusion) of male and female gametes producing genetic variation in the offspring
32
Extinction
The permanent loss of all living members of a species from an area or from the world
33
Gravitropism
The response of a plant to gravity
34
Metabolism
All of the reactions taking place in a cell or the body of an organism
35
Veins
Blood vessels that carry blood towards the heart. They usually carry deoxygenated blood and have valves to prevent the backflow of blood
36
FSH (follicle stimulating hormone)
A hormone which causes the eggs to mature in the ovary
37
Oestrogen
Female sex hormone that controls the development of secondary sexual characteristics in girls at puberty, and the build-up and maintenance of the uterus lining during the menstrual cycle
38
Receptors
Cells that detect stimuli - changes in the internal or external environment.
39
Carbon cycle
The cycling of carbon through the living and non-living world
40
Cell membrane
The lipid membrane around the contents of a cell that controls what moves in and out of the cell
41
Biomass
The amount of biological material in an organism
42
Plasmolysis
The state of plant cells when so much water is lost from the cell by osmosis that the vacuole and cytoplasm shrink and the cell membrane pulls away from the cell wall
43
Glycogen
Carbohydrate store in animals (typically in the muscles and liver)
44
Embryonic stem cells
Stem cells from an early embryo that can differentiate to form any specialised cells of the body
45
Competition
The process by which living organisms compete with each other for limited resources such as food, light, or reproductive partners
46
Central nervous system (CNS)
The part of the nervous system where information is processed. It is made up of the brain and spinal cord
47
Species
The smallest group of clearly identified organisms in Linnaeus's classification system, often described as a group of organisms that can breed together and produce fertile offspring
48
Motor neurones
Carry impulses from the central nervous system to the effector organs
49
Vasodilation
The dilation or opening up of the blood vessels
50
Cloning
The production of identical offspring by asexual reproduction
51
Communicable disease
Disease caused by pathogens that can be passed from one organism to another (infectious diseases)
52
Ionising radiation
Radiation (particle or electromagnetic) which can cause ionisation of molecules in cells that it passes through. This can lead to cell death, mutation and/or cancer
53
Alveoli
Tiny air sacs in the lungs that increase the surface area for gaseous exchange
54
Stem cells
Undifferentiated cells with the potential to form a wide variety of different cell types
55
Endocrine system
The glands that produce the hormones that control many aspects of the development and metabolism of the body, and the hormones they produce.
56
Exothermic reaction
A reaction that transfers energy to the surroundings
57
Domain
The highest level of classification. There are three domains - Archaea, Bacteria, and Eukaryota
58
Dialysis
The process of cleansing the blood through a dialysis machine when the kidneys fail
59
Capillaries
The smallest blood vessels. They run between individual cells and have a wall that is only one cell thick to allow movement of substance to and from the blood
60
Median average
The middle value in an ordered list of numbers
61
Plasma
The clear yellow-liquid part of the blood that carries dissolved substances and blood cells around the body
62
Fatty acids
Part of the structure of a lipid molecule
63
Insulin
A hormone involved in the control of blood sugar levels (converts free glucose in the blood into glycogen)
64
Pathogens
Microorganisms that cause disease (bacteria, viruses, protists, fungi)
65
Pituitary gland
Endocrine 'master gland' found in the brain that secretes a number of different hormones into the blood in response to different conditions to control other endocrine glands in the body
66
Transect
A measured line or area along which ecological measurements are made
67
Mode average
The number which occurs most often in a set of data
68
Casual mechanism
Something that explains how one factor influences another
69
Red blood cells (erythrocytes)
Biconcave cells without a nucleus that contain the protein haemoglobin and carry oxygen around the body in the blood
70
Tissue culture
A modern way of cloning plants that allows thousands of new plants to be created from one piece of plant tissue
71
Extremophile
An organism that can survive and reproduce in extreme conditions
72
Heterozygote
Individual with different alleles for a characteristic (e.g. Bb)
73
Digestive system
The organ system where food is digested and absorbed
74
Cytoplasm
The water-based gel in which the organelles of all living cells are suspended and most of the chemical reactions of life take place
75
Penicillium
The mould from which the antibiotic penicillin is extracted
76
Tropism
The responses of plant roots and shoots to environmental stimuli such as light or gravity
77
Gibberellins
Plant hormones that are important in initiating seed germination
78
Bile
A substance that neutralises stomach acid to give a higher pH for the enzymes from the pancreas and small intestine to work well. It is not an enzyme. Also emulsifies lipids to aid digestion
79
Active transport
The movement of substances from a lower concentration to an area of higher concentration against the concentration gradient. Requires energy from respiration
80
Nerve
A bundle of hundreds or even thousands of neurones
81
Dominant allele
The phenotype will be apparent in the offspring even if only one of the alleles is inherited (shown with an upper case letter)
82
Effectors
Areas (usually muscles or glands) that bring about responses in the body
83
Zygote
The single new cell formed by the fusion of gametes in sexual reproduction (the fertilised egg)
84
Biodiversity
A measure of the variety of all the different species of organisms in a given environment
85
Vena cava
The large vein that brings deoxygenated blood from the body into the right atrium of the heart
86
Haemoglobin
The red iron containing pigment that carries oxygen around the body in the red blood cells (forms oxyhaemoglobin when bound to oxygen)
87
Non-communicable diseases
Diseases which are not infectious and cannot be passed from one organism to another. Usually inherited or caused by lifestyle.
88
Adaptations
Special features that make an organism particularly well suited to the environment where it lives
89
Tissue
A group of specialised cells with a similar structure and function
90
Glucagon
A hormone involved in the control of blood sugar levels (converts stored glycogen into glucose)
91
Palisade mesophyll
The upper layer of the mesophyll tissue in plant leaves made up of closely packed cells that contain many chloroplasts for photosynthesis
92
Sperm
The male sex cells or gametes that carry the genetic material from the male parent
93
Type 2 diabetes
A disorder where the body cells no longer respond to the insulin produced by the pancreas
94
Ovulation
The release of a mature egg (ovum) from the ovary
95
Photosynthesis
The process by which plants synthesise food using carbon dioxide, water, and light
96
Platelets (thrombocytes)
Fragments of cells in the blood that play a vital role in the clotting mechanism of the blood
97
Guard cells
Surround the stomata in the leaves of plants and control their opening and closing
98
Genetic engineering
The process by which scientists can manipulate and change the genotype of an organism
99
Epidermal
The name given to cells that make up the epidermis or outer layer of an organism
100
Speciation
The process by which two species evolve from a single original species by natural selection
101
Carbohydrases
Enzymes that speed up the breakdown of carbohydrates into simple sugars
102
Abundance
An indication of how common or rare a particular type of organism is in a given environment
103
Mitochondria
The organelle responsible for carrying out aerobic cellular respiration in a cell
104
Chlorophyll
The green pigment contained in the chloroplasts
105
Osmosis
The diffusion of water through a partially permeable membrane from a dilute solution (which has a high concentration of water) to a concentrated solution (with a low concentration of water) down a concentration gradient
106
Glycerol
Part of the structure of a lipid molecule
107
Inoculate
Introducing microorganisms to a culture medium, or introducing modified microorganisms into an individual to protect them against disease
108
Alleles
Different versions of the same gene, sometimes referred to as variants
109
Eukaryotic cells
Cells that have membrane bound organelles e.g. a nucleus
110
Urea
The waste product formed by the breakdown of excess amino acids in the liver
111
Trophic level
Feeding levels in an ecosystem
112
Mutation
A change in the genetic material of an organism
113
Decomposers
Microorganisms that break down waste products and dead bodies
114
Pulmonary artery
The large blood vessel that takes deoxygenated blood from the right ventricle of the heart to the lungs
115
Double circulatory system
The circulation of blood from the heart to the lungs is separate from the circulation of blood from the heart to the rest of the body
116
Phloem
The living transport tissue in plants that carries dissolved food (sugars) from the leaves to the rest of the plant
117
Organ
An aggregation (collection ) of different tissues working together to carry out specific functions
118
Amylase
An enzyme that speeds up the digestion of starch into glucose
119
Placebo
A medicine that does not contain the active drug being tested, used in clinical trials of new medicines
120
Active site
The area on an enzyme where the substrate attach
121
Incident energy
Light from the Sun arriving at the surface of the Earth
122
Stent
A metal mesh placed in a blocked or partially blocked artery. They are used to open up the blood vessel by the inflation of a tiny balloon
123
Lactic acid
The end product of anaerobic respiration in animal cells
124
Vaccine
Dead, inactive, or recombinant pathogenic material used in vaccination to develop immunity to a disease in a healthy person
125
Producers
Organisms such as plants and algae that can make food using processes such as photosynthesis or chemosynthesis
126
Algae
Simple aquatic organisms (protista) that make their own food by photosynthesis
127
Thermoregulatory centre
The area of the brain that is sensitive to the temperature of the blood
128
Glucose
A simple sugar - C6H12O6
129
Ventricles
Chambers at the base of the heart that contract to force blood out of the heart to the lungs or body
130
Evolutionary trees
Models used to explain the evolutionary links between groups of organisms
131
Auxin
A plant hormone that controls the responses of plants to light (Phototropism) and gravity (Gravitropism)
132
Hypotonic
(Osmosis) A solution that is less concentrated / more dilute than the cell contents
133
Cell cycle
The process of cell division in a body cell, ending in the production of two identical daughter cells. Comprised of interphase (growth 1, synthesis, growth 2), and mitosis
134
Bases (DNA)
Nitrogenous compounds that make up part of the structure of DNA and RNA. They are represented by the letters A, T, C, G, and U.
135
Stomata
Openings/pores in the leaves of plants, particularly on the underside and opened and closed by guard cells, allowing gases to enter and leave the leaf
136
Clinical trials
The testing of potential new drugs on human volunteers
137
Community
A group of interdependent living organisms in an ecosystem
138
Sample size
The size of a sample in an investigation
139
White blood cells
Blood cells involved in the immune system of the body. They engulf pathogens and produce antibodies and antitoxins
140
Malignant tumours
Invade neighbouring tissues and spread to different parts of the body in the blood where they form secondary tumours. They are also known as cancers
141
Permanent vacuole
A permanent space in the cytoplasm of a cell filled with cell sap
142
Neurones
Basic cells of the nervous system that carry minute electrical impulses around the body
143
Virus
Pathogens that are much smaller than bacteria and can only reproduce inside living cells of other organisms
144
Interdependence
The network of relationships between different organisms within a community, for example each species depends on other species for food, shelter, pollination, seed dispersal, etc.
145
Homeostasis
The general name for the processes which keep the internal conditions of a cell or organism constant (and optimum for function)
146
Polydactyly
A dominant inherited disorder that results in babies born with extra fingers and/or toes
147
Reflex arcs
Bring about a reflex action. They involve the sense organ, sensory neurone, relay neurone and motor neurone
148
Denatured
The breakdown of the molecular structure of a protein so it no longer functions (the changing of the shape of a protein preventing its proper function)
149
Carbohydrates
Molecules that contain only carbon, hydrogen, and oxygen. They provide the energy for the metabolism and are found in foods such as rice, potatoes, and bread
150
Therapeutic cloning
A process where an embryo is produced that is genetically identical to the patient so the cells can then be used in medical treatments
151
Aorta
The artery that leaves the heart from the left ventricle and carries oxygenated blood to the body
152
Aphids
Insects that penetrate the plant phloem and feed on the dissolved nutrients. They act as plant pathogens and are also vectors that carry pathogens to healthy plant tissue
153
Hormones
Chemicals produced in one area of the body of an organism that have an effect on the functioning of another area of the body. In animals hormones are produced in glands.
154
Homozygote
Individual with two identical alleles for a characteristic (e.g. BB or bb)
155
Suspensory ligaments
The ligaments that connect the lens of the eye to the ciliary muscles
156
Sensory neurone
Neurone that carries impulses from the sensory organs/receptors to the central nervous system
157
Isotonic
(Osmosis) A solution that is the same concentration as the cell contents
158
Reflexes
Rapid automatic responses of the nervous system that do not involve conscious thought
159
Lipase
Enzymes that speed up the breakdown of lipids into fatty acids and glycerol
160
Bacteria
Single-celled prokaryotic organisms
161
Statins
Drugs used to lower blood cholesterol levels and improve the balance of HDLs to LDLs in the blood
162
Ribosomes
The organelle responsible for protein synthesis in a cell
163
Xylem
The non-living transport tissue in plants that transports water from the roots to the leaves and shoots
164
Atria
The upper chambers of the heart
165
Cerebellum
Region of the brain concerned with coordinating muscular activity and balance
166
Selective reabsorption
The process in the kidney where the materials needed in the body such as glucose, some mineral ions, and water are reabsorbed back into the blood from the filtrate
167
Secondary consumer
Animals that eat the primary consumers
168
Oxygen debt
The extra oxygen that must be taken into the body after exercise has stopped to complete the aerobic respiration of lactic acid
169
Vasoconstriction
The constriction or narrowing of the blood vessels
170
Cell wall
The rigid structure around plant and algal cells. It is made of cellulose and strengthens/supports the cell
171
Tumour
A mass of abnormally growing cells that forms when the cells do not respond to the normal mechanisms that control growth and when control of the cell cycle is lost
172
Pulmonary vein
The large blood vessel that carries oxygenated blood from the lungs back to the left atrium of the heart
173
Selective breeding
Human lead natural selection. Where humans actively choose organisms to reproduce based on desired characteristics
174
Amino acids
Molecules made up of carbon, hydrogen, oxygen, and nitrogen that are the building blocks of proteins
175
Simple sugars
Small carbohydrate units, for example glucose
176
Organ system
A group of organs that work together to carry out specific functions and form organisms
177
Hypertonic
(Osmosis) A solution that is more concentrated than the cell contents
178
Differentiate
The process where cells become specialised for a particular function
179
Asexual reproduction
Reproduction involving only one individual. The offspring is identical to the parent. There is no fusion of gametes or mixing of genetic information
180
Binary fission
Reproduction by simple cell division, e.g. when bacteria divide
181
Cellulose
The complex carbohydrate that makes up plant and algal cell walls and gives them strength.
182
Partially permeable membrane
A membrane that allows only certain substances to pass through
183
Meiosis
Two stage process of cell division that produces four non-identical daughter cells (gametes) with reduced chromosomal numbers compared to regular cells.
184
Lipids
Include fats and oils and are found in foods such as butter, olive oil, and crisps. They are made of carbon, hydrogen and oxygen
185
Aerobic respiration
An exothermic reaction in which glucose is broken down using oxygen to produce carbon dioxide and water and release energy for the cells (occurs in the mitochondria)
186
Endothermic reaction
A reaction that requires a transfer of energy from the surroundings to the reactants
187
Adrenaline
The hormone that prepares the body for flight or fight
188
Testosterone
The main male sex hormone that controls the male secondary sexual characteristics at puberty and the production of sperm
189
Quantitative sampling
Recording the number of organisms rather than just the type
190
Recessive
A phenotype that will only show up in the offspring if both of the alleles coding for that characteristic are inherited (shown using a lower case letter)
191
Carcinogens
Agents that cause cancer or significantly increase the risk of developing cancer
192
Benign tumours
Growths of abnormal cells that are contained in one area, usually within a membrane, and do not invade other tissues
193
Chloroplasts
The organelles in which photosynthesis takes place
194
Chlorosis
The yellowing seen on the leaves of plants when they cannot make chlorophyll due to lack of magnesium ions
195
Stimuli
Changes in the external or internal environment that can be detected by receptors
196
Medulla
The region of the brain concerned with unconscious activities such as controlling the heart rate and breathing rate
197
Type 1 diabetes
A disorder where the pancreas fails to produce sufficient insulin
198
Nucleus
Organelle found in many living (eukaryotic) cells containing the genetic information surrounded by the nuclear membrane
199
Ovaries
Female gonads that produce eggs and sex hormones
200
Correlation
An apparent link or relationship between two factors
201
Proteases
Enzymes that speed up the breakdown of proteins into amino acids
202
Cancer
The common name for a malignant tumour, formed as a result of changes in cells that lead to uncontrolled growth and division
203
Prokaryotic cells
Cells which have a cytoplasm surrounded by a cell membrane, and a cell wall that does not contain cellulose. The genetic material is a DNA loop that is free in the cytoplasm and not enclosed by a nucleus. Sometimes there are one or more small rings of DNA called plasmids
204
Spongy mesophyll
The lower layer of mesophyll tissue in plant leaves that contains some chloroplasts and many large air spaces to give a big surface area for the exchange of gases
205
Transpiration
The loss of water vapour from the leaves of plants through the stomata when they are opened to allow gas exchange for photosynthesis. It involves evaporation from the surface of the cells and diffusion through the stomata
206
Limiting factors
Factors which restrict / limit the rate of a reaction, for example light intensity in photosynthesis
207
Sex chromosomes
Carry the information that determines the sex of an individual (X and Y in humans)
208
Agar gel
Solid culture medium used to grow bacteria and fungi
209
ADH
Helps control the water balance of the body and affects the amount and concentration of urine produced by the kidney
210
Cystic fibrosis
An inherited disorder affecting the cell membrane. Typically affects the lungs, digestive, and reproductive system and is inherited through a recessive allele
211
Natural selection
The process by which evolution takes place. Organisms produce more offspring than the environment can support. Only those that are most suited to their environment will survive to breed and pass on their useful characteristics to their offspring.
212
Carriers
Individuals who are heterozygous for a recessive allele linked to a genetic disorder. Carriers have one healthy allele so they are not affected themselves but they can pass on the affected allele to their offspring
213
Ventilation
Movement of air or water into and out of the gas exchange organ, for example lungs or gills
214
Classification
The organisation of living organisms into groups according to their similarities
215
Punnett square diagram
A way of modelling a genetic cross and predicting the outcome using probability
216
Archaea
One of the three domains, containing primitive forms of bacteria that can live in many of the extreme environments of the world
217
Enzymes
Biological catalysts, usually proteins
