Biology 2 Keywords Flashcards Preview

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Flashcards in Biology 2 Keywords Deck (181):
1

Active Site

The site on an enzyme molecule that has a special shape that holds the substrate molecule during the reaction.

2

Active Transport

Movement of molecules into the cell using energy from respiration. It allows the cell to build up a high concentration of certain molecules inside the cell, against a concentration gradient. For example, the way the plant root cells take in mineral salts from the soil.

3

Adenine

It is a base (a chemical found in DNA) and pairs up with Thymine.

4

Adult Stem Cell

A stem cell found in differentiated tissue that can produce a few kinds of differentiated cell.

5

Aerobic Respiration

Respiration that needs oxygen.

6

Alimentary Canal

The muscular tube that runs from the mouth to the anus including the oesophagus, stomach, small intestine and large intestine.

7

Allele

Every gene comes in different types called alleles. So a gene for eye colour may come in a 'blue type' allele and a 'brown type' allele.

8

Amino Acid

A small molecule that is the building block of proteins.

9

Amylase

A carbohydrase enzyme which breaks down starch to simple sugars.

10

Anaerobic Respiration

Respiration that does not need oxygen.

11

Antibodies

Proteins that bind to the microorganisms that cause disease and destroy them.

12

Anus

Where undigested food is passed out of the body.

13

Aorta

A major artery leading away from the heart.

14

Arteries

Vessels that transport blood away from the heart.

15

Asexual Reproduction

The formation of a new individual without fertilisation, using the process of mitosis to create offspring identical to the parent organism.

16

Base

The two strands in a molecule of DNA (in the double helix structure) are linked together at regular intervals by chemicals called bases. The bases are adenine, cytosine, thymine and guanine.

17

(Complementary) Base Pair

The bases always pair up in the same way because of the complementary or matching shape of the molecules. Adenine (A) pairs up with thymine (T) and cytosine (C) pairs up with guanine (G).

18

Base Triplet

A group of three bases that codes for a particular amino acid.

19

Beta-carotene

Substance in the human diet from which the body makes vitamin A.

20

Bifidobacteria

Example of probiotic bacteria.

21

Bile

An alkaline substance made by the liver that helps in the digestion of fats.

22

Bile Duct

Tube that connects the gall bladder to the small intestine.

23

Biodiveristy

The variety of species present within a given area.

24

Blood Vessels

Tube that connects the blood as it flows around the body.

25

Bolus

A ball-shaped mass of chewed food.

26

Capillary

Tiny blood vessels with thin walls to allow diffusion of substances into and out of the blood.

27

Carbohydrases

Enzymes which catalyse the breakdown of carbohydrates.

28

Carbohydrate

Compound made up from carbon, hydrogen and oxygen, used for energy by organisms.

29

Cardiac Output

The volume of blood the heart can pump out in one minute, calculated using the equation, cardiac output + stroke volume x heart rate.

30

Catalyst

A substance that speeds up the rate of a reaction without being used up in the reaction.

31

Cell

The basic units of life in which many chemical reactions needed to sustain life (for example, growth) take place.

32

Cell Membrane

Thin layer which forms a semi-permeable barrier around the outer surface of the cytoplasm on the cell and controls the movement of substances into and out of the cell.

33

Cell Wall

Relatively rigid structure that surrounds plant and bacterial cells, which support the cell and help it keep its shape.

34

Cellulose

Cell walls are made of tough cellulose which supports the call and allow it to keep its shape.

35

Chlorophyll

Green substance in chloroplasts that absorbs energy from sunlight.

36

Chloroplasts

Organelle in plant cells that contains chlorophyll, and is where photosynthesis takes place.

37

Cholesterol

A fat which is made in the liver and carried around the body in the blood. High levels are associated with an increased risk of heart disease.

38

Chromosomal DNA

The DNA which makes up the chromosomes of a cell.

39

Chromosome

Thread-like structures found in the nucleus of the cell which carry the genetic information.

40

Circulatory System

Organ system involving the heart and blood vessels which oxygenates blood and moves it around the body.

41

Clone

An individual created by a form of asexual reproduction to produce offspring that is genetically identical to the parent.

42

Codon

Another name for a base triplet.

43

Concentration Gradient

A situation when a solute is in a gradually increasing concentration from one region to another.

44

Cytoplasm

The liquid gel which makes up a lot of the body of a cell and is where many chemical reactions take place.

45

Cytosine

It is a base (a chemical found in DNA) and pairs up with guanine.

46

Daughter Cells

Cell produced from division of a parent cell.

47

Denature

To break down/change shape, as proteins denature with excess heat.

48

Deoxygenated

Without oxygen.

49

Differentiate

Specialise, develop into different kinds, as in cells that become nerve, muscle or bone cells.

50

Diffusion

The random movement and spreading of particles. When there is a concentration gradient, there is a net (overall) diffusion of particles from areas of high concentration to regions of lower concentration.

51

Digestion

The breakdown of large food insoluble molecules into small, soluble food molecules.

52

Digestive System

The system of organs which brings about digestion of the food in the body.

53

Diploid

A cell that has two sets of chromosomes. In humans, almost all cells except the sperm and egg cells are diploid.

54

Distribution

The places in which a certain organism can be found in an area.

55

DNA Replication

When the chromosomes are copied before cell division occurs.

56

Double Helix

The spiral structure of a DNA molecule, produced by two strands of joined by complementary base pairs.

57

Ecosystem

An area in which all the living organisms and all non-living physical features in the area form a stable relationship that needs no input from outside the area to remain stable.

58

Electron Microscope

Instrument which magnifies specimens using a beam of electrons.

59

Elongation

Getting longer.

60

Embryo

The ball of cells produced by cell division of the zygote. A very early stage in the development of a new individual.

61

Embryonic Stem Cell

A cell from an early stage of division of an embryo that can produce almost any kind of differentiated cell.

62

Emulsify

Turn into an emulsion, a mixture in which particles of one liquid are suspended in another liquid.

63

Enucleate

Remove the nucleus from a cell.

64

Environment

An organism's surroundings; made up of very different factors such as air, water, soil and other living organisms.

65

Enzyme

A protein molecule made by living cells that speeds up the rate of a reaction.

66

Evolution

The development of new species over time through a process of natural selection.

67

Excess Post-Exercise Oxygen Consumption (EPOC)

Period of time after exercise in which a greater than usual amount of oxygen is needed by the body for various processes, including the removal of lactic acid cell repair. This used to be known as oxygen debt.

68

Faeces

Undigested, waste material.

69

Fat

Chemicals that are used to store energy in organisms.

70

Fatty Acid

Part of the structure of a fat or oil.

71

Fertilise

When two gametes fuse.

72

Flagella

Whip-like protein bodies found on the outside of bacterial cells and other cells which beat back and forwards and can be used for movement.

73

Fossil Record

The collection of fossils identified from different periods of time that can be interpreted to form a hypothesis about the evolution of life on Earth.

74

Fossil

The preserved traces or remains of an organism which lived a very long time ago.

75

Functional Foods

Foods which are not eaten for nutritional value but which claim to make you healthier.

76

Gall Bladder

An organ that stores the bile made by the liver and releases it into the small intestine via the bile duct.

77

Gamete

Sex cell (sperm or egg cells), produced in the male or female reproductive organs by meiosis.

78

Gas Exchange

A process in the lungs in which oxygen diffuses from the lungs into the blood and carbon dioxide diffuses from the blood into the lungs.

79

Gene

A section of DNA which codes for a specific protein.

80

Genetic Code

The code produced by the sequence of bases in genetic material (e.g. DNA).

81

Genetic Engineering

The process of removing a gene from one organism and inserting it into the DNA in a cell from another organism.

82

Genetically Modified Organisms (GMOs)

An organism that has had a gene from another species introduced (e.g. inserting a gene for producing human insulin into a bacterium).

83

Genome

All of the genetic information (DNA) of an organism, as a list in order of every base.

84

Glucose

A simple sugar that is broken down in cells to release energy during respiration. It is also produced during photosynthesis.

85

Glycerol

Part of the structure of a fat or oil.

86

Golden Rice

Genetically engineered rice which produces beta-carotene in the rice grains turning them a golden yellow colour.

87

Growth

Increase in size, length and mass, as well as increase in cell number.

88

Guanine

It is a base (a chemical found in DNA) and pairs up with cytosine.

89

Habitat

The place where an organism usually lives.

90

Haemoglobin

The red iron-containing pigment found in red blood cells.

91

Haploid

Having one set of chromosomes, as in gametes.

92

Herbicide

Chemical which kills plants, usually used on weeds.

93

Human Genome Project (HGP)

A project to sequence (order) all of the base pairs of the human genome involving scientists from many different countries working together.

94

Hydrogen Bond

Base pairs are joined together by weak hydrogen bonds.

95

Implant

In reproduction, placing an embryo into the uterus of a female animal to develop.

96

Lactic Acid

The waste product of anaerobic respiration in animal cells.

97

Lactobacillus

Example of probiotic bacteria.

98

Large Intestine

Organ that absorbs water from digested material.

99

Left Atrium

One of the four chambers of the heart that receives blood from the pulmonary vein.

100

Left Ventricle

One of the four chambers of the heart that receives blood from the left atrium and pumps it into the aorta.

101

Light Microscope

Instrument which magnifies specimens using light and lenses.

102

Limiting Factor

A single factor that when in short supply can limit the rate of a process such as photosynthesis.

103

Lipase

Enzyme which digests fats to fatty acids and glycerol.

104

Liver

Organ that has a range of functions including secretion of bile.

105

Lock-and-Key Hypothesis

An idea that describes the relationship of a substrate and then active site of an enzyme to help explain how enzymes work.

106

Meiosis

Division of parent cell that produces genetically different haploid cells.

107

Messenger RNA (mRNA)

The molecule formed during DNA transcription that carries the code from the chromosome to a ribosome.

108

Mitochondrion (plural mitochondria)

The site of cellular respiration where glucose is broken down using oxygen to release energy, which is needed for reactions in the cell.

109

Mitosis

Division of a parent cell that produces two genetically identical diploid cells.

110

Mutation

A change in the base sequence of DNA (often as a result of exposure to radiation).

111

Nucleus

In chemistry, the positively charged centre of an atom. In physics, the central part of an atom, containing protons and neutrons.

112

Oesophagus

Muscular tube between the mouth and stomach.

113

Oligosaccharides

A type of carbohydrate which is a common prebiotic.

114

Organ

A group of different tissues working together to carry out a particular function.

115

Organ System

A group of organs working together to carry out a particular function in the body.

116

Organelles

Tiny structures that carry out specific jobs, for example, nucleus and mitochondria.

117

Osmosis

The diffusion of water from a region of high concentration of water molecules to a region of lower concentration of water molecules, through a partially permeable membrane.

118

Oxygenated

With oxygen.

119

Pancreas

Organ that makes digestive enzymes and secretes them into the first part of the small intestine.

120

Parent Cell

The cell that divides to produce daughter cells.

121

Partially Permeable Membrane

A thin sheet of material that will allow certain small molecules to diffuse through it (e.g. water) but not other larger ones.

122

Pentadactyl

Five fingered

123

Pepsin

An example of a protease enzyme found in the stomach.

124

Percentile

The value of a variable below which a certain percentage of observations fall. For example the 20th percentile of an ordered set of data indicates that 20% of the data points are the same or lower than this value.

125

Peristalsis

The waves of muscular contraction that move food along the alimentary canal.

126

Phloem

Living tissue that transports sugars around a plant.

127

Photosynthesis

A series of enzyme-catalysed reactions carried out in the green parts of plants. Carbon dioxide and water combine to form glucose. This process requires light energy from sunlight.

128

Pitfall Trap

A trap used to catch small animals that move on the ground. The animals are unable to escape.

129

Plant Stanol Esters

Oily substances found in plants that appear to lower blood cholesterol levels in people.

130

Plasma

The liquid component of the blood that carries all the suspended cells and dissolved substances.

131

Plasmid DNA

A circle of extra DNA found only in bacteria cells.

132

Platelets

Cell fragments that are important in the clotting mechanism of the blood.

133

Polypeptide

A chain of amino acids that will form part of a protein.

134

Pond Net

A net used to collect aquatic organisms from ponds, rivers and streams.

135

Pooter

A simple device used to collect small invertebrates.

136

Population Size

The numbers of individuals of a species in an area.

137

Prebiotics

Substances which cannot be digested by human digestive enzymes but which act as food for probiotic bacteria in the intestine.

138

Probiotics

Foods containing live bacteria that produce lactic acid in the gut and may improve the health of your digestive system.

139

Protease

Enzyme which digests protein to amino acids.

140

Protein Synthesis

The building up of a protein molecule by joining together amino acids.

141

Protein

A polymer made up of amino acids, containing carbon, hydrogen, oxygen and nitrogen. Genes carry the instructions for making proteins.

142

Pulmonary Artery

Arteries that carry deoxygenated blood from the right ventricle to the lungs.

143

Pulmonary Vein

Veins that carry oxygenated blood from the lungs to the left atrium.

144

Quadrat

A square frame of known area, such as 1m2, which is placed on the ground to get a sample of the organisms living in a small area.

145

Random Sampling

A method of sampling where the locations are selected randomly.

146

Red Blood Cells

Biconcave discs containing haemoglobin that give the blood its red colour and carry oxygen around the body to the tissues.

147

Representative Sample

A sample that has approximately the same characteristics as those of the whole study area.

148

Respiration

A series of reactions occurring in all living cells in which glucose is broken down to release energy.

149

Ribosome

Small structures in the cytoplasm of a cell where mRNA is translated into an amino acid chain.

150

Right Atrium

One of the four chambers of the heart that receives blood from the vena cava.

151

Right Ventricle

One of the four chambers of the heart that receives blood from the right atrium and pumps it into the pulmonary artery.

152

Root Hair Cell

Cells found near the tip of roots that have thin extensions (that look a bit like hairs). Water enters root hair cells by osmosis. The long thin extension gives a large surface area.

153

Saliva

Lubricates food and makes it easier to swallow, also contains amylase which begins digestion of carbohydrate.

154

Sampling

Looking at a small portion of an area or population.

155

Septum

A thin membrane that separates the two sides of the heart.

156

Sexual Reproduction

The formation of a new individual from the fertilisation of a female gamete (egg cell) by a male gamete (sperm cell). This individual is genetically different from its parent.

157

Small Intestine

Organ where digestion is completed and nutrients are absorbed.

158

Specific

Only one, as in an enzyme only catalyses the reaction of one kind of substrate.

159

Starch

A carbohydrate, made by joining together thousands of glucose molecules.

160

Stem Cell

An unspecialised cell that can divide to produce more stem cells or different kinds of specialised cell.

161

Stomata (singular stoma)

A tiny pore in the lower surface of a leaf, which when open, allows gases to diffuse into and out of the leaf.

162

Stomach

Organ that makes acid and some enzymes.

163

Stroke Volume

The volume of blood the heart can pump out with each beat.

164

Substrate

The substance that is changed by an enzyme in a chemical reaction.

165

Sugars

A group of compounds formed from carbon, hydrogen and oxygen.

166

Surface Area to Volume Ratio

The total amount of surface area of an object divided by its volume. The surface area to volume ratio of a small object or organism is larger than that of a large object of a given shape, for example a cube. The surface area to volume ratio of a wide and thin structure, or a wrinkled structure, is greater than that of a spheroidal one.

167

Surrogate Mother

A female who is not related to the embryo that is implanted in her uterus to develop.

168

Sweep Net

A net used to collect insects from long grass or the canopy of a tree, by "sweeping" it through the grass or leaves.

169

Systematic Sampling

A method of sampling where the samples are selected from the population at regular or systematic intervals, (e.g. a sample every metre or every fifth person).

170

Thymine

It is a base ( a chemical found in DNA) and pairs up with adenine.

171

Tissue

A group of specialised cells that all carry out the same function.

172

Transcription

When a strand of mRNA is produced by complementary pairing of bases with one strand of DNA in the nucleus.

173

Uterus

Womb

174

Vacuole

Membrane-bound space in the cytoplasm filled with cell sap, a store of water and nutrients. It helps to support the plant by keeping the cells rigid.

175

Valves

Flaps of tissue in the heart that stop the blood flowing backwards.

176

Veins

Vessels that transport blood back to the heart.

177

Vena Cava

A major vein leading to the heart.

178

Villi

Fingerlike folds of the lining of the small intestine which greatly increases the surface area for the absorption/diffusion of digested food products into the blood.

179

White Blood Cells

Several different types of cells that are all part of the body's defence system against disease.

180

Xylem

Tissue made of dead hollow cells that transports water and dissolved minerals from the roots to other parts of the plant.

181

Zygote

A fertilised egg cell.