Exam 😈 Flashcards

Question

what are the 3 stop codons

Answer 1

UAA, UAG or UGA

Answer 2

the part of the gene that gives the information for making proteins

Answer 3

parts of the gene that isn’t the coding region

Answer 4

exons and introns

Answer 5

upstream and downstream

Answer 6

the part that contain the instructions for the synthesis of the protein and are both transcribed and translated

Answer 7

parts in the coding region that are transcribed but are cut out during RNA processing and therefore are not translated

Answer 8

promoter operator leader

Answer 9

The promoter is where transcription factors and RNA polymerase binds to initiate transcription

Answer 10

It is a binding site for repressor proteins, which are proteins that prevents RNA polymerase binding to a promoter, and thus transcription cannot be initiated

Answer 11

TrpL (1), then three attenuator regions (2, 3, 4)

Answer 12

further regulation of transcription

Answer 13

group of linked structural genes with a common promoter and operator that is transcribed as a single unit

Answer 14

repression and attenuation

Answer 15

1. trp binds to the repressor protein causing a configurational change in its shape, allowing it to be active 2. This allows the repressor to bind at the operator 3. RNA polymerase is unable to bind to the promoter and transcription does not occur. Thus the operon is OFF

Answer 16

1. the repressor is unable to bind to the operator (as it is still in an inactive form) 2. RNA polymerase can bind to the promoter and start transcription of the structural genes; thus, the operon is ON

Answer 17

1. trpL can be quickly translated. When the ribosome translates this region quickly (to the leader peptide), it will quickly detach from the mRNA 2. This allows a hairpin loop to form between the mRNA produced in regions 1 and 2. 3. A terminator hairpin loop between the mRNA in regions 3 and 4 is also able to form. 4. the RNA polymerase detaches from the DNA, transcription is stopped

Answer 18

1. trpL is translated slowly 2. As the ribosome translates the gene, the ribosome pauses at the trp codon to wait for enough tryptophan to be available to produce the leader polypeptide 3. the ribosome stays attached to region 1, and therefore no hairpin loop can form between the mRNA in regions 1 and 2, but one will form between 2 and 3 4. this hairpin loop does not cause the RNA polymerase to detach and prevents the terminator hairpin of regions 3 and 4 forming 5. RNA polymerase continue remains attached to the trp operon, transcription and translation can occur

Answer 19

large molecules made up of amino acids

Answer 20

an amino group and a carboxyl group. The difference between amino acids are the R group

Answer 21

primary, secondary, tertiary, quaternary

Answer 22

linear sequence of amino acids, each protein has a different primary structure and therefore different functions

Answer 23

folded amino acid sequences depending on the R group

Answer 24

- Alpha helix - Beta-pleated sheet - Random coiling

Answer 25

secondary structure in proteins that appears as a tight twist

Answer 26

secondary structure in proteins that appears as folded sheets, with a change in direction of the polypeptide chain

Answer 27

secondary structure in proteins that does not fit in as either a alpha helix or beta-pleated sheet

Answer 28

total irregular 3D folding held together by ionic or hydrogen bonds forming a complex shape

Answer 29

A structure in which two or more polypeptide chains interact to form a protein

Answer 30

increase the rate of almost all the chemical reactions and to do this within the prevailing conditions of temperature and pH within cells

Answer 31

The complete array of proteins produced by a single cell or an organism in a particular environment.

Answer 32

translation (in cytosol ribosomes)

Answer 33

transporting some of the proteins to various sites within a cell

Answer 34

packages proteins into vesicles for export from the cell through exocytosis

Answer 35

move to the plasma membrane of the cell, where they fuse with it and discharge their protein contents to the exterior through exocytosis

Answer 36

the process in cells by which an enzyme makes a copy of DNA from RNA

Answer 37

when only specific genes or small sections of DNA are required to be synthesised, we use mRNA instead of DNA

Answer 38

1. mRNA is isolated from cytosol 2. Poly-A tail is added to the mRNA 3. a primer is added and binds to this tail, then the DNA lengthens from nucleotides being added 4. polymerase is added, catalysing the building of the complementary DNA strand 5. the double stranded DNA is produced

Answer 39

reverse transcriptase

Answer 40

cleave (cut) DNA at specific recognition sequences known as restriction sites, splitting DNA into smaller fragments

Answer 41

a particular order of nucleotides

Answer 42

blunt and sticky ends

Answer 43

at points directly opposite each other

Answer 44

the DNA fragments are joined directly together through the use of DNA ligase

Answer 45

cut one strand at one point but cut the second strand at a point that is not directly opposite, leaving over hanging ends.

Answer 46

The DNA ligase enzyme connects the single-stranded DNA together via the sugar-phosphate backbones

Answer 47

sugar–phosphate backbones

Answer 48

is a technique used to amplify a segment of DNA accurately and quickly

Answer 49

Taq polymerase, because it can withstand great heat needed for the breakdown of DNA (heat resistant)

Answer 50

1. Denaturing 2. Annealing 3. Extension

Answer 51

1. DNA is heated to 94 degrees 2. separation happens by raising the temperature of the PCR mixture, the hydrogen bonds between the complementary DNA strands break

Answer 52

around 94 for a minute

Answer 53

Short segments of single-stranded DNA, known as primers, are added, binding to the 3' ends (target DNa sequences) initiating DNA synthesis. These primers bind to their complementary sequences on the single-stranded template DNA

Answer 54

55 for 2 mins

Answer 55

The polymerase (Taq polymerase) uses the primers as a starting point and extending the primers, synthesising the new strands of DNA by adding nucleotides

Answer 56

72 for one minute

Answer 57

DNA polymerases synthesise DNA strands by adding (DNA) nucleotides (deoxyribose, ACTG) RNA polymerases synthesise RNA strands by adding (RNA) nucleotides (ribose, AUCG)

Answer 58

a technique for sorting a mixture of DNA fragments through an electric field on the basis of different fragment lengths

Answer 59

1.The DNA sample (fragments) is combined with DNA loading dye 2. it is then placed in a well at one end of a slab of aragose gel 3. This agarose gel is immersed in a buffer (salt) solution 4.The gel is then exposed to an electric field with the positive (+) pole (anode) at the far end and the negative (−) pole (cathode) at the starting origin. The DNA is attracted to the positive pole 5. Smaller fragments move through the agarose gel faster compared to larger fragments 6. fragments appear as bands on a gel which can be interpreted in various ways

Answer 60

the smaller fragments are able to better move and weave through the porous agarose gel compared to larger fragments

Answer 61

a technique for identifying DNA from different individuals based on variable regions known as short tandem repeats (STRs)

Answer 62

short tandem repeats, sequences of just two to seven base pairs are repeated over and over

Answer 63

The number of repeats of an STR marker can vary between people and each variation is a distinct allele, so people with the same amount of repeats will match with certain DNA that is found

Answer 64

a small, circular, double-stranded DNA molecule, separate from the cell’s chromosomal DNA that exist naturally in bacterial cells

Answer 65

plasmids that carry foreign DNA

Answer 66

1. DNA of the plasmid is cut using a specific cutting enzyme in order to create sticky ends 2. foreign DNA fragments are prepared using the same endonuclease so that the foreign DNA has sticky ends complementary to the cut plasmid (mostly done through reverse transcription) 3. foreign DNA fragments and the plasmids are mixed, and, in some cases, their ‘sticky ends’ pair by using weak hydrogen bonds. A recombinant plasmid has been created 4. The joining enzyme, ligase, is added and this makes the joins permanent through covalent bonding

Answer 67

needs to be transferred into a bacterial cell (bacterial transformation)

Answer 68

process in which bacterial cells take up segments of foreign DNA that become part of their genetic make-up

Answer 69

genes carried by plasmids for certain traits, often for antibiotic resistance

Answer 70

A marker inserted into a plasmid that will change colour based on if the DNA has been taken up by the bacteria, lacZ is an example

Answer 71

quaternary, meaning multiple peptide chains

Answer 72

reverse transcription, because don't have to splice out introns

Answer 73

1. cut with endonucleases 2. add insulin genes using ligase 3. transformations of bacteria with plasmids and expression of proteins 4. extract protein (insulin + B-galactosidase) from bacteria 5. purify both A and B and combine each to each other

Answer 74

by heat shock or electroporation

Answer 75

to increase the chance of bacteria to take up the recombinant plasmid as chances are low

Answer 76

Cells are briefly placed in an electric field that shocks them and appears to create holes in their plasma membranes, allowing the plasmid entry

Answer 77

an agent or vehicle used to transfer pathogens or genes between cells and organisms

Answer 78

The bacterial cells are suspended in an ice-cold salt solution and then transferred to 42 °C for less than one minute. This treatment appears to increase the fluidity of the plasma membranes of the bacterial cells and increases the chance of uptake of plasmids

Answer 79

the process which a gene of interest is located and cloned to produce multiple copies

Answer 80

DNA that is formed by combining DNA from different sources, often from different kinds of organisms

Answer 81

proteins that are expressed by recombinant DNA present in an organism

Answer 82

a tool for precise and targeted genome editing that uses specific RNA sequences to guide an endonuclease

Answer 83

a restriction enzyme, that will cut at the right positions based on the gRNA (guide) also known as sgRNA (synthetic/single guide RNA)

Answer 84

short, repeated segments of DNA, with each repeated segment being separated by a length of spacer DNA.

Answer 85

a region of non-coding DNA between genes

Answer 86

1. Targeting 2. binding 3. cleaving 4. DNA repair

Answer 87

Cas9 will locate and bind to a common sequence in the genome known as the PAM sequence

Answer 88

a sequence of bases (NGG, N is any nucleotide) that is in the genome

Answer 89

Cas9 unwinds the DNA, and if the DNA at that location matches with the 20 strands of gRNA then it will bind together with complimentary base pairing

Answer 90

Binding triggers Cas9 to change shape and gives the signal to cleave both strands of DNA upstream of PAM. This disables the viral DNA

Answer 91

the cell will try and repair the DNA, leading to mutation (error prone). Disabling the gene Or scientists will add another sequence or modify the specific sequence allowing for knocking out genes or replacing faulty ones with healthy ones

Answer 92

are organisms that has had their genome altered using genetic engineering technology

Answer 93

sub-group of GMOs, that contain genetic material from different species

Answer 94

- addition of gene segment - silencing of gene

Answer 95

- increased photosynthesis efficiency - greater crop yield - faster growth rates

Answer 96

reactions occurring in cells that lead to the formation of a product from a reactant.

Answer 97

a series of linked biomechanical reactions

Answer 98

- anabolic pathways - catabolic pathways

Answer 99

The total activity of the reactions of all biochemical pathways in a living organism

Answer 100

a compound on which an enzyme acts

Answer 101

anabolic pathways are energy-requiring or endergonic

Answer 102

These pathways turn simple molecules into more complex ones

Answer 103

These pathways break down complex molecules into more simple ones

Answer 104

Catabolic pathways are energy-releasing or exergonic

Answer 105

Photosynthesis, where glucose molecules are synthesised from carbon dioxide and water using radiant energy from the Sun

Answer 106

Aerobic cellular respiration, where glucose molecules are broken down into carbon dioxide and water molecules

Answer 107

factors that increase rate of reaction

Answer 108

yes, each different reaction will be catalysed by a specific enzyme

Answer 109

no, enzymes are all catalysts but not all catalysts are enzymes

Answer 110

minimum amount of energy required to initiate a chemical reaction

Answer 111

region of an enzyme that binds temporarily with the specific substrate of the enzyme

Answer 112

- Influence the stability of bonds in the reactants - Providing an alternative reaction pathway;

Answer 113

lower activation levels

Answer 114

1. the enzyme and substrate with join to form the E-S complex (when it binds to the active site) 2. the substrate forms weak bonds with particular amino acid residues (in the protein) at the active site.

Answer 115

an organic molecule that acts with an enzyme to alter the rate of a reaction

Answer 116

a non-protein molecule or ion that is essential for the normal functioning of some enzymes

Answer 117

no, coenzymes are cofactors but not all cofactors and coenzymes

Answer 118

cofactors that do not contain carbon and include metal ions such as magnesium or copper

Answer 119

small non-protein organic molecules that are essential for the function of particular enzymes

Answer 120

- prosthetic groups - coenzymes

Answer 121

cofactors that are tightly bound to an enzyme and are essential for it to function as a catalyst.

Answer 122

prosthetic groups are tightly bound to an enzyme, whereas, coenzymes are loosely bound

Answer 123

- NAD - NADP - FAD - ATP - CoA (coenzyme A)

Answer 124

- transfers of atoms or groups of atoms, such as hydrogens, phosphate groups and acetyl groups - energy transfers

Answer 125

they are high in energy and have a group that can be transferred. In simple they are electron donors

Answer 126

they have low energy, and accept groups. In simple they are electron acceptors

Answer 127

- temperature - pH - substrate concentration

Answer 128

there is more movement of particles, therefore more collisions possible with substrate and enzyme

Answer 129

As pH increases or decreases from optimum pH, the rate of reaction and the activity of an enzyme decreases.

Answer 130

the rate of reaction increases with increasing substrate concentration — but only up to a point. Beyond this, any further increase in substrate concentration produces no significant change in reaction rate (active sites are all occupied)

Answer 131

substances that prevent the normal action of an enzyme and therefore slow the rate of enzymes-controlled reactions

Answer 132

reversible inhibition irreversible inhibition

Answer 133

- competitive inhibition - non-competitive inhibition

Answer 134

inhibition in which a molecule binds to the active site of a molecule instead of the usual substrate

Answer 135

inhibition in which a molecule binds to the allosteric site of an enzyme causing a conformation change in the active site

Answer 136

inhibitor molecules prevent the formation of the E–S complexes (as active site is partially occupied)

Answer 137

as the binding of the inhibitor to the allosteric site changes the shape of the enzyme's active site the E-S complex cannot form

Answer 138

occurs when a specific molecule can form a strong covalent bond with an enzyme at its active site, so that the normal substrate is permanently blocked from accessing the active site

Answer 139

Heavy metals

Answer 140

- prevent waste, such as would occur if pathway products were made in excess of cell requirements - prevent the build-up in cells of products to potentially harmful levels - prevent depletion of substrates

Answer 141

- allosteric regulation - feedback regulation

Answer 142

control of the reaction rate of enzymes through conformational changes in enzymes. This occurs when a regulator molecule binds to the allosteric site

Answer 143

- allosteric inhibitors - allosteric activators

Answer 144

their binding produces a change of shape in the enzyme that stops enzyme activity; they act like an OFF switch

Answer 145

the shape change resulting from the binding produces an increase in enzyme activity; they act like an ON switch

Answer 146

the end product of a metabolic pathway acts as an inhibitor of the key enzyme that catalyses the first step in a pathway.

Answer 147

the process by which plants use the radiant energy of sunlight trapped by chlorophyll to build carbohydrates (glucose) from carbon dioxide and water.

Answer 148

- light-dependent stage - light-independent stage

Answer 149

6 carbon dioxide + 6 water = glucose + 6 oxygen (gas)

Answer 150

to transform sunlight energy that is captured by chlorophyll into the chemical energy of loaded coenzymes

Answer 151

to assemble simple inorganic carbon dioxide molecules into more complex organic glucose molecules

Answer 152

Calvin cycle

Answer 153

chloroplasts, in the chlorophyll pigment inside (in the cytosol of plants)

Answer 154

capture the radiant energy of sunlight, bringing it into cells as the starting point of photosynthesis

Answer 155

thylakoids grana stroma

Answer 156

flattened membranous sacs in chloroplasts that contain chlorophyll

Answer 157

stacks of thylakoids are known as grana, where a singular stack is a granum

Answer 158

fluid inside the chloroplasts, containing the enzymes that are involved in calvin cycle

Answer 159

involved in the capture of sunlight and the transformation of its energy to the chemical energy of loaded coenzymes, NADPH and ATP.

Answer 160

thylakoid (within the grana)

Answer 161

- water - ADP + Pi - NADP+

Answer 162

- oxygen - ATP - NADPH

Answer 163

the energy caught by the chlorophylls make the electrons have high energy (excited) and the splitting of water molecules gives H+ ions (protons). This then allows NADPH to form as well as ATP

Answer 164

a supply of high-energy loaded ATP molecules a supply of high-energy loaded NADPH coenzymes that can act as donors of hydrogen ions and electrons

Answer 165

water + 18ADP + NADP into 6O2 + 18ATP + NADPH

Answer 166

inorganic carbon dioxide molecules (CO2) are built into energy-rich reduced organic molecules, such as glucose (C6H12O6).

Answer 167

the stroma

Answer 168

Rubisco, and the NADPH (donate H and e-) and ATP (energy source) from the previous stage

Answer 169

- ATP - NADPH - CO2

Answer 170

- ADP + Pi - NADP+ - Glucose

Answer 171

inorganic carbon is converted in organic CO2 thru carbon fixation NADPH donate hydrogens and electrons as molecules are reduced to higher energy levels ATP supplies energy for anabolic steps

Answer 172

they are categorised into how they fix carbon into glucose

Answer 173

These plants carry out the original Calvin Cycle, using Rubisco, and are prone to photorespiration

Answer 174

moist and cool conditions

Answer 175

use the Rubisco enzyme to fix inorganic carbon dioxide from the air and it enters the Calvin cycle joined to a carrier molecule (RuBP)

Answer 176

in the stroma of the leaf mesophyll cells

Answer 177

a process in which plants take up oxygen rather than carbon dioxide in the light, resulting in photosynthesis being less efficient. (Rubisco takes up O2 instead of CO2)

Answer 178

the critical enzyme in C3 plants that brings carbon dioxide from the air into the Calvin cycle where the glucose is made

Answer 179

rubisco binds oxygen rather than carbon dioxide

Answer 180

the active site can readily accommodate the oxygen molecules as well as the carbon dioxide molecules, so the two different molecules are in competition for the active site of Rubisco.

Answer 181

- temperature increases - conditions dry out

Answer 182

the ability of the Rubisco enzyme to distinguish between carbon dioxide and oxygen decreases and, as a result, Rubisco will increasingly bind oxygen.

Answer 183

C3 plants close their stomata to prevent water loss. This closure blocks the entry of carbon dioxide needed as input to the Calvin cycle and limits the exit of oxygen produced creating a high oxygen low CO2 environment inside the mesophyll cells

Answer 184

carry out an adapted Calvin cycle, in which carbon fixation and glucose production occur in different cells

Answer 185

These cells will thrive in warm and tropical regions

Answer 186

- bundle sheath cells have chloroplasts - mesophyll cells that are arranged in a close association around the bundle sheath cells

Answer 187

leaf mesophyll cells and bundle sheath cells

Answer 188

Carbon dioxide is converted into malic acid, in the mesophyll cells PEP carboxylase catalyses the binding of carbon dioxide to an acceptor molecule (malic acid) (this is called carbon fixation)

Answer 189

PEP carboxylase

Answer 190

Calvin cycle (glucose production) occurs in the bundle sheath cells produce a steady supply of carbon dioxide from the breakdown of malic acid that raises the carbon dioxide concentration in their leaves. This allows the RuBisco in the bundle sheath cells to bind only to CO2

Answer 191

two stages of the Calvin cycle occurring at different times

Answer 192

thrive in hot and arid environments, that are exposed to droughts

Answer 193

at night (stomata are open)

Answer 194

in the day (when the stomata are closed)

Answer 195

mesophyll cells

Answer 196

PEP carboxylase

Answer 197

it is stored in vacuoles waiting for the stomata to close (day time)

Answer 198

- carbon dioxide levels in leaves are high - oxygen levels are low (as happens when water is freely available) - when temperatures are moderate.

Answer 199

- cacti - pineapples

Answer 200

- wheat - rice - potato

Answer 201

- maize/corn - sugar cane

Answer 202

- the amount of light reaching their leaves - the temperature of the environment - the availability of water - the concentration of carbon dioxide

Answer 203

any environmental condition that restricts the rate of biochemical reactions in an organism.

Answer 204

increases as light intensity increases, until it reaches a maximal point.

Answer 205

the point where further increases in light intensity have no effect and the rate of photosynthesis stays constant

Answer 206

more chlorophylls are energised

Answer 207

rate of photosynthesis declines and then stops because closed stomata prevent the uptake of carbon dioxide needed for the Calvin cycle

Answer 208

the rate of photosynthesis will also decline and stop because the lack of oxygen for cellular respiration in root cells stops water uptake

Answer 209

As the ambient temperature is increased, the rate of photosynthesis also increases due to an increase in collisions between the reactants and the enzymes involved in photosynthesis. Eventually, as the heat passes a certain threshold, the enzymes start to denature, in which the tertiary structure of an enzyme is lost. This causes the rate to again decrease.

Answer 210

the rate of photosynthesis will increase until it levels off due to limiting factors

Answer 211

no, because CO2 is not apart of the reaction

Answer 212

the process of converting chemical energy into a useable form by cells, typically ATP.

Answer 213

- aerobic - anaerobic

Answer 214

glucose + oxygen → carbon dioxide + water + ATP

Answer 215

30-32, 36-38 in optimal conditions

Answer 216

1. glycolysis 2. Krebs cycle 3. electron transport chain

Answer 217

glucose is broken down into pyruvate

Answer 218

makes a supply of energy-rich loaded coenzymes

Answer 219

transfers energy from electrons supplied by loaded coenzymes to make ATP.

Answer 220

glucose, 2x (ADP + Pi) and 2x (NAD+)

Answer 221

2x (pyruvate), 2x ATP, 2x (NADH) and two hydrogen ions (protons)

Answer 222

mitochondria

Answer 223

the matrix

Answer 224

gel like solution within their inner membrane

Answer 225

the cristae

Answer 226

It folds in the inner membrane of the mitochondria, it holds enzyme

Answer 227

pyruvate oxidation

Answer 228

pyruvate loses a C and an H atom, forming a 2C acetyl group that is delivered to the Krebs cycle by coenzyme A.

Answer 229

FAD+ and NAD+

Answer 230

2 x (acetyl CoA (acetyl groups)), 6 x (NAD+), 2 x (FAD) and 2 x (ADP + Pi)

Answer 231

4 x (CO2), 6 x (NADH), 2 x (FADH2) and 2 x (ATP)

Answer 232

Electrons are transferred along enzyme complexes The first input of high-energy electrons to the ETC comes from loaded NADH coenzymes. FADH2 also donates its high-energy electrons to an acceptor, but further down the chain. Oxygen accepts electrons and hydrogen ions, forming water

Answer 233

As electrons transfer from one enzyme complex to the next, the energy released is ultimately used to power the production of ATP from ADP and Pi.

Answer 234

- 6 (oxygen) - 26-28 (ADP + Pi) - 10 (NADH) - 2 (FADH2)

Answer 235

electron transport chain

Answer 236

processes that occur without the presence of oxygen, producing a net of 2 ATP molecules

Answer 237

occurs in human skeletal muscle cells when the supply of oxygen to the cells by aerobic cellular respiration cannot keep up with their demand for ATP.

Answer 238

the cytosol

Answer 239

much faster, this is why it is able to produce enough ATP

Answer 240

- alcohol (ethanol) fermentation - lactic acid fermentation

Answer 241

glycolysis short add on stage

Answer 242

pyruvate, ADP and NADH is turned into ATP, lactic acid and NAD+

Answer 243

alcohol and carbon dioxide is created, NAH+ is regenerated for glycolysis again

Answer 244

animals use lactic acid yeast uses alcohol

Answer 245

- temperature - oxygen concentration - glucose concentration

Answer 246

an increase in glucose concentrations leads to an increase in the rate of cellular respiration. This rate eventually levels off from rate-limiting factors

Answer 247

the organic material from plants and animals; it is a renewable source of energy.

Answer 248

Biofuels are any fuel source derived from biomass.

Answer 249

1. deconstruction of biomass to increase surface area 2. hydrolysis (breaking down) of biomass by enzymes 3. yeast fermentation to produce ethanol 4. purification and dehydration to remove debris and water

Answer 250

- increase photosynthetic efficiency - crop yield - crop quality

Answer 251

could improve the Rubisco, by knocking out parts of genes that result in rubisco binding to O2

Answer 252

molecules or parts of a molecule that stimulate immune response through the adaptive immune response.

Answer 253

proteins produced by plasma cells in response to antigens and which react specifically with the antigen that induced their formation

Answer 254

They are another term for antibodies

Answer 255

an innate reaction by the immune response to foreign particles or injury resulting in redness and swelling

Answer 256

T cells that are activated by cytokines to bind to antigen–MHC-I complexes on infected host cells and kill infected body cells

Answer 257

self or non-self

Answer 258

those that are not foreign and are thus usually tolerated by the immune system

Answer 259

Non-self antigens can be identified as invaders and can be attacked by the immune system.

Answer 260

the cell surface receptors that tell them if they are self or non-self (MHC)

Answer 261

receptor proteins on the surface of cells that identify the cells as ‘self’

Answer 262

all nucleated cells

Answer 263

provide a site for binding of antigens to occur, that allows cells to be recognised as ‘self’ so they will not be attacked

Answer 264

- mainly on specific white blood cells, including antigen-presenting cells (macrophages and dendritic cells) - and helper T cells.

Answer 265

the antigen presenting cells present antigens on their surface on these MHC-II markers, which bind to helper T cells to help activate the adaptive immune response.

Answer 266

A pathogen or infectious agent is a biological agent that causes disease or illness to its host

Answer 267

- cellular - and non-cellular

Answer 268

- bacteria - parasites - fungi - protozoa

Answer 269

single-celled eukaryotic cells

Answer 270

They are singular chromosome and double stranded DNA, prokaryotic cells

Answer 271

any disease-causing agent made up of cells that can reproduce independently without relying on the host machinery

Answer 272

can be both eukaryotes or prokaryotes

Answer 273

damage particular tissues of their host organism and cause disease

Answer 274

- viruses - prions

Answer 275

non-cellular pathogens that use the host cell in order to replicate their genetic material

Answer 276

virions (viral particle)

Answer 277

the extracellular form of a virus that can transfer between hosts

Answer 278

infectious particles made of protein that lack nucleic acids (folded proteins)

Answer 279

- genetic material, either DNA or RNA, organised as a single molecule or as several molecules - a protein shell, known as a capsid, that surrounds the genetic material.

Answer 280

destruction of cells by rupturing the membrane of the cell

Answer 281

The mode of release of viral particles from an infected cell may be by budding or by cell lysis.

Answer 282

triggers normal proteins in the brain to fold into an abnormal structure

Answer 283

the time period between infection and the first appearance of the symptoms of a disease

Answer 284

an antigen that elicits an allergic response

Answer 285

cells from both the innate and adaptive system

Answer 286

the type of immunity that is present from birth, is fast acting but not long lasting, and produces non-specific (generic) responses against classes of pathogens

Answer 287

an immune response that is specific to a particular antigen and develops through contact with an antigen

Answer 288

ability of the adaptive immune response to remember antigens after primary exposure

Answer 289

- cell-mediated immunity - humoral immunity

Answer 290

immune response that is mediated by immune cells

Answer 291

immune response mediated by soluble molecules in the blood, lymph and interstitial fluid that disable pathogens

Answer 292

white blood cells

Answer 293

class of white blood cells found in all tissues including blood, lymph nodes and spleen, and which play a role in specific immunity

Answer 294

white blood cells that recognise antigens or pathogens and produce a large number of antibodies specific to an antigen

Answer 295

white blood cells that mature in the thymus and participate in the adaptive immune response

Answer 296

B cells and T cells are activated and adaptive immune responses occur

Answer 297

a physical, chemical and microbiological barriers to prevent pathogens from gaining entry to the body

Answer 298

the actions of immune cells and soluble proteins mounting a rapid but non-specific attack against pathogens that gain entry to the body.

Answer 299

the recognition of specific antigens by lymphocytes

Answer 300

innate immunity

Answer 301

adaptive immunity

Answer 302

innate barriers that act to prevent the entry of pathogens into the body

Answer 303

- physical barriers - chemical barriers - microbiological (microbiota) barriers

Answer 304

stomata (close to prevent pathogen entry)

Answer 305

intact skin

Answer 306

a innate barriers that use enzymes to kill pathogens and prevent invasion into a host

Answer 307

sweat (with lysozyme)

Answer 308

caffeine (Toxic to fungi and insects)

Answer 309

innate barriers involving normal flora in the body

Answer 310

by an enzyme called lysozyme that kills the pathogens

Answer 311

when pathogens have entered the body (cut in skin)

Answer 312

bulk movement of solid material into cells where the cell engulfs a particle to form a phagosome

Answer 313

- soluble proteins - inflammation - immune cells

Answer 314

- natural killer cells (NK cells), - mast cells, - eosinophils - macrophages - neutrophils - dendritic cells

Answer 315

white blood cells leukocytes

Answer 316

- neutrophils - dendritic cells - macrophages

Answer 317

in the bloodstream

Answer 318

a type of white blood cell that has small granules inside their cytoplasm

Answer 319

eosinophils, neutrophils

Answer 320

- dendritic cells - macrophages

Answer 321

- pathogen recognised by pattern recognition receptor - pathogen engulfed by phagosome - Lysosomes fuse with the phagosome - pathogen is destroyed by toxic chemicals and lysosome - material is discharged by exocytosis

Answer 322

some antigens or sub-units from the digested pathogen on the MHC-ll markers (activating adaptive immune system)

Answer 323

protein receptors present on phagocytic cells of the innate immune system that enable these cells to recognise and bind to pathogens, with recognition being at a generic leve

Answer 324

they identify eliminate and engulf pathogens by phagocytosis and clear dead cells and debris. Also antigen presenting (can activate adaptive immune response)

Answer 325

Neutrophils are abundant immune cells that are usually the first to the site of an infection, engulfing and destroying pathogens.

Answer 326

Dendritic cells are professional antigen-presenting cells, engulfing pathogens and presenting their antigens to T cells to activate the adaptive immune response.

Answer 327

assist in defending against larger parasitic agents that are too large to be engulfed by phagocytosis. They contain granules with toxic chemicals and histamine

Answer 328

lymphocytes that kill virus-infected cells through apoptosis

Answer 329

There granules contain granzymes and perforin. The perforin makes holes in the cells plasma membrane allowing the granzymes to enter. This enzymes induces apoptosis

Answer 330

the process by which immune cells release various chemicals (such as histamine and antimicrobials) stored within secretory vesicles known as granules

Answer 331

they are vital in the inflammatory response. As well as releasing histamines that increase vascular permeability, they also release cytokines that attract other immune cells to help destroy the pathogen. (out of granules) (also contain heparin)

Answer 332

a substance involved in inflammation and allergic reactions that causes blood vessels to dilate and become more permeable to immune cells

Answer 333

the immune cells attacking the pathogen

Answer 334

complement proteins and cytokines

Answer 335

proteins that assist other innate immune cells and can destroy bacterial cells by lysis

Answer 336

signalling molecules of the immune system

Answer 337

interferons, proteins secreted by some cells, in response to a virus infection, that helps uninfected cells resist infection by that virus

Answer 338

dissolved in blood plasma

Answer 339

- opsonising pathogens - recruiting immune cells involved in an inflammatory response (chemotaxis) - destroying bacterial pathogens by lysis

Answer 340

the coating of the surface of pathogen cells by complement proteins, making the pathogens more susceptible to phagocytosis

Answer 341

phagocytes have receptors for complement proteins on their plasma membranes, and these bind to the opsonised microbes. Allowing for direct binding to the pathogen

Answer 342

movement of a cell or organism in response to a chemical substance

Answer 343

one of the defence mechanisms resulting from activation of complement proteins that destroys pathogen cells by osmotic shock

Answer 344

Small complement peptides that diffuse from the pathogen surface act as chemical signals, attracting immune cells involved in the inflammatory response

Answer 345

The activation of a complement protein occurs when the protein is cut (cleaved) into two fragments — a larger activated protein and a smaller peptide fragment. This sequence of reactions starts a cascade that can neither be stopped nor reversed. Or C3 makes direct contact with molecules on the surface of a pathogen

Answer 346

Once a body cell is infected with viruses, the cell secretes interferons. That cell is doomed, but the interferons that it secretes into its surroundings act as warning signals to nearby cells so that they can prepare in advance for a possible virus infection

Answer 347

The MAC inserts into the plasma membrane of the pathogen and produces a pore that allows fluid to enter, causing the pathogen cell to swell and burst — explosive death by osmotic shock

Answer 348

- redness - pain - heat - swelling - pus

Answer 349

- vascular stage - cellular stage - resolution stage

Answer 350

- chemical signals (such as histamine) are released to attract phagocytes - dilation and increased leakiness of capillary (vasodilation)

Answer 351

- phagocytes consume bacteria and cell debris - phagocytes migrate to area

Answer 352

- platelets move out of the capillary to seal wound - an abscess forms, containing pus, with dead phagocytes and cell debris

Answer 353

- production and maturation of immune cells - the removal of excess fluids from body tissues - absorption and transportation of fatty acids to the digestive system - allowing for the process of antigen recognition by T and B lymphocytes

Answer 354

- lymph - lymphatic vessels - primary lymphoid organs - secondary lymphoid organs

Answer 355

bone marrow and thymus

Answer 356

lymph nodes and spleen

Answer 357

- source of pluripotent stem cells (where immune cells originate) - and site of maturation of B cells

Answer 358

is the fluid in the lymphatic system that gets squeezed out of blood vessels

Answer 359

site where T cells mature after being released from the bone marrow

Answer 360

- filters the blood passing through it, clearing the blood of bacteria and viruses as well as worn-out red blood cells - contains T cells and B cells that detect and respond to infectious agents in the blood - contains other immune cells

Answer 361

Lymph nodes are the sites in which antigen recognition occurs

Answer 362

This is where antigen-presenting cells display their antigens to their specific T and B lymphocytes, leading to expansion of the appropriate lymphocytes for adaptive immunity

Answer 363

These can initiate either the humoral adaptive immune system (through stimulating the clonal selection and clonal expansion of B cells) or the cell-mediated immune system (through stimulating the clonal selection and expansion of cytotoxic T cells).

Answer 364

1. pathogen is engulfed by APCs 2. pathogen is degraded into fragments (my fusion with lysosome) 3. some of the fragments are presented on MHC-II markers 4. They present these fragments to helper T cells by moving to the lymph nodes (antigen presentation) 5. Helper T cell binds to the antigen (via receptors) and activates the helper cell 6. Helper T cells release cytokines (interleukins) that activate B or T cells

Answer 365

lymph nodes

Answer 366

- activate cytotoxic T cells - activate B cells into becoming antibody-producing plasma cells - activate macrophages to remove - antibody-coated pathogens by phagocytosis

Answer 367

- specificity - Immunological memory

Answer 368

the ability to recognise and respond to specific antigens

Answer 369

- T cells and B cells - antibodies, also known as immunoglobulins - lymph nodes, organs where B cells and T cells meet foreign antigens and are activated

Answer 370

- B plasma cells - B memory cells

Answer 371

Involves the actions of antibodies that identify and bind to extracellular pathogens, to toxins and to other extracellular foreign antigens. Antibodies are products of special B plasma cells.

Answer 372

bone marrow

Answer 373

involves various actions of T cells. Cytotoxic T cells eliminate body cells that are infected by pathogens or have abnormal or missing self markers. They eliminate intracellular pathogens.

Answer 374

1. After the helper T cell activates the interleukins they naive B cells are activated 2. The B cells undergo clonal expansion to produce clones of B cells 3. These clones differentiate into plamsa B cells or memory B cells 4. plasma B cells secrete antibodies to the antigen, memory B cells remain in the lymphoid tissue 5. then PIANO occurs via antibodies

Answer 375

B and T cells that haven't been activated

Answer 376

they bind to soluble antigens, making them insoluble, causing them to precipitate out of the solution, creating a solid (more visible)

Answer 377

when the correct (specific) naive B or T cell binds to the antigen

Answer 378

when the naive B or T cell differentiates

Answer 379

light and heavy chains (light short, heavy long)

Answer 380

- variable region (ends that bind to antigens) - constant region (most of the antibody)

Answer 381

PIANO precipitation inflammation agglutination neutralisation opsonisation

Answer 382

they bind to the surface antigens on pathogens to form antigen–antibody complexes, causing them to clump together (more visible)

Answer 383

they release histamine, triggering inflammation

Answer 384

they bind to surface antigens on pathogens and form a coating that neutralises pathogens by blocking their receptors so that the pathogens cannot attach to healthy body cells and infect them

Answer 385

they bind to the surface antigens on pathogens to form antigen–antibody complexes and tag the pathogen for destruction. This activates phagocytes and complement proteins

Answer 386

a specific response in which cytotoxic T cells destroy virus-infected cells using perforin and granzyme B

Answer 387

the MHC-I marker

Answer 388

1. After the helper T cells release interleukins it will activate naive T cells 2. They then undergo clonal expansion to produce these T cell clones 3. These clones differetiate into cytotoxic T cells and memory T cells 4. The cytotoxic T cells release perforin and granzyme B, destroying the infected cell via it intiating apoptosis

Answer 389

1. release perforin, making a hole in the cell 2. secrete granules (granzyme B) enter the cell and initiate apoptosis

Answer 390

- actively (active immunity) - passively (passive immunity)

Answer 391

antibodies are produced by a person’s own adaptive immune system

Answer 392

occurs naturally, without deliberate intervention

Answer 393

- naturally - artificially

Answer 394

is induced through a deliberate intervention

Answer 395

a type of immunity in which the body produces antibodies in response to a normal infection by a pathogen

Answer 396

the deliberate and artificial introduction of a disabled pathogen or its toxin to the body (vaccination)

Answer 397

antibodies are acquired by a person from an external source

Answer 398

a form of immunity in which an individual receives antibodies from a natural source, such as through breastfeeding

Answer 399

the injection of antibodies, providing immediate response, (antivenom)

Answer 400

a condition in a living animal or plant body that impairs the normal functioning of an organ, part, structure or system

Answer 401

- non-infectious - infectious

Answer 402

a disease caused by a newly identified or previously unknown agent

Answer 403

reappearance of a known disease after a significant decline in incidence

Answer 404

a situation when, over a relatively short time, many people worldwide contract a specific disease as it spreads from a region of origin

Answer 405

the widespread occurrence of an infectious disease in a community or in a restricted geographic area at a particular time

Answer 406

the host or the pathgoen

Answer 407

- direct transmission - indirect transmission

Answer 408

mechanism of transmission of pathogenic agents that involves direct person-to-person contact, such as by kissing or sexual contact

Answer 409

mechanism of transmission of pathogenic agents that does not involve direct person-to-person contact, such as by airborne droplets or by ingestion of contaminated food

Answer 410

a person with an infectious disease showing no symptoms but able to infect others

Answer 411

the basic reproduction number that identifies the expected number of individuals a person with a certain disease will infect

Answer 412

- prevention - vaccination - medication - surveillance - modification of environment - infection control standards

Answer 413

spraying chemicals to eliminate breeding of the pathogens

Answer 414

washing hands

Answer 415

a class of antimicrobial drug used in the treatment and prevention of bacterial infections that act either by killing pathogenic bacteria or by inhibiting their growth

Answer 416

mandated programs that set a schedule in which vaccinations against specific diseases should be administered

Answer 417

indirect protection, at the population level, against an infectious disease; the protection is created by the presence in the population of a high proportion of individuals who are vaccinated against the particular disease

Answer 418

- ELISA - microscope

Answer 419

a technique known as enzyme linked immunosorbent assay, which can detect specific antigens or antibodies

Answer 420

specifically designed antibodies used in the treatment of some diseases such as cancer and autoimmune disease

Answer 421

- a mouse is injected with antigens, allowing for their B cells to produce and antibody which is withdrawn (from spleen) - then they are fused with collected tumor cells in suspension - they make hybrid cells (hybridomas) - these cells are isolated to grow separately - they then grow many of these mAbs

Answer 422

- treat cancer - treat autoimmune disease

Answer 423

- naked - conjugated

Answer 424

mAbs that dont have any molecules attached

Answer 425

mAbs that have other molecules attached

Answer 426

- stop growth of blood vessels - signal immune attack - block growth factors - deliver anticancer or radioisotopes to the cancer cells

Answer 427

- block signalling to prevent growth by inhibiting blood vessels (bind to growth factor) - they block signals for cell division (cant replicate cancer cells) - they can bind to tumor cells to signal attack from immune system

Answer 428

they bring the anticancer and radioisotopes to the cancer cells (kill the cells)

Answer 429

a disease where antibodies attack self cells

Answer 430

alter the course of an autoimmune disease by directing the antibodies against major histocompatibility antigens to prevent them triggering an autoimmune response

Answer 431

members of one species living in one region at a particular time

Answer 432

sum total of genetic information present in a population

Answer 433

The total set of this genetic information in an individual

Answer 434

the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Answer 435

the amount of genetic variation there is within a population’s gene pool

Answer 436

the proportion of a specific allele in a population

Answer 437

1. times the # of organisms by 2 (for 2 alleles) to gain total number of alleles in the pool 2. write the number of alleles for each type (10 of a, 6 of A) 3. divide each # of alleles by the total alleles in the pool for the allele frequency of that allele.

Answer 438

- changes in environmental selection pressures leading to natural selection - genetic drift - gene flow

Answer 439

external agents which influence the ability of an individual to survive in their environment

Answer 440

- physical agents - chemical agents - biological agents

Answer 441

climate change

Answer 442

pollutants in soil or water

Answer 443

a process in which organisms better adapted for an environment are more likely to pass on their genes to the next generation

Answer 444

the ability to survive and pass genetic material on to the next generation

Answer 445

relative higher genetic fitness of a phenotype compared with other phenotypes controlled by the same gene

Answer 446

1. There is variation within the population’s gene pool. 2. struggle for all individuals in the gene pool to survive. Environmental selection pressures act upon the population 3. Individuals that are better adapted to their environment are more likely to survive and reproduce, passing their alleles on to the next generation 4. The alleles that allow for survival will be inherited by subsequent generations and they can increase in frequency in the gene pool over time

Answer 447

random changes, unpredictable in direction, in allele frequencies from one generation to the next owing to the action of chance events

Answer 448

- bottleneck effect - founder effect

Answer 449

chance effects on allele frequencies in a population as a result of a major reduction in population size

Answer 450

chance effects on allele frequencies in a population that is formed from a small unrepresentative sample of a larger population

Answer 451

- immigration - emigration

Answer 452

the movement of individuals and their alleles out of a population, and thus out of a gene pool

Answer 453

- a natural disaster - a new disease to which the population has not previously been exposed - human activity, such as destruction of habitat or large scale poaching.

Answer 454

the movement of individuals and their genetic material between populations

Answer 455

the movement of individuals and their alleles into a population, and thus into a gene pool

Answer 456

increases it

Answer 457

decreases it

Answer 458

decreases it

Answer 459

decreases it

Answer 460

decreases it

Answer 461

increases it

Answer 462

a permanent alteration in the DNA sequence of a gene that leads to the formation of new alleles

Answer 463

chemical or physical agent that can cause mutation in DNA

Answer 464

- radiation (x-rays) - chemicals (benzene) - pathogenic (bacteria)

Answer 465

it is first necessary that the mutation occur in the germline of an organism so that it may be passed to the next generation.

Answer 466

- advantageous - neutral - disadvantageous

Answer 467

a mutation that affects a single nucleotide

Answer 468

- conservative - non-conservative

Answer 469

- substitution (silent, nonsense, missense) - frameshift (insertion, deletion)

Answer 470

- insertion - deletion

Answer 471

- silent - nonsense - missense

Answer 472

a type of missense mutation in which the substituted amino acid is very different in properties to the initial amino acid

Answer 473

because DNA is degenerate

Answer 474

a type of mutation in which a single base change does not change the amino acid and final protein expressed

Answer 475

a type of mutation in which a single base change leads to a STOP signal being received, resulting in a truncated protein

Answer 476

a type of mutation in which a single base change leads to the change in the amino acid translated in the protein chain

Answer 477

a type of missense mutation in which the substituted amino acid is similar in properties to the initial amino acid

Answer 478

type of mutation in which, as a result of insertion or deletion of a base, all codons from that point are affected

Answer 479

A nucleotide deletion also causes a frameshift with all bases from the point of the deletion being moved back by one position to compensate for the deletion

Answer 480

An insertion mutation occurs when one nucleotide base is added to a DNA strand

Answer 481

part of the chromosome will join to another one

Answer 482

the entire genome is replicated (so instead of 2 of each chromosomes there may be 3 of every chromosome).

Answer 483

- deletion of part of a chromosome - duplication or gain of part of a chromosome - translocation between non-homologous chromosomes - inversion (when a segment of a chromosome rotates through 180 degrees)

Answer 484

- limit the population's ability to adapt to changing environmental conditions, - can make them vulnerable to becoming susceptible to disease and even to becoming extinct

Answer 485

the process by which humans breed animals or plants in such a way to increase the proportion of chosen phenotypic traits

Answer 486

the loss or gain of a single chromosome

Answer 487

- bacterial resistance - antigenic drift (viruses) - antigenic shift (viruses)

Answer 488

antibiotics, because of the selection pressure of the antibiotics being present

Answer 489

1. There is variation within the population’s gene pool. 2. Humans select individuals with a desirable trait. 3. These individuals breed and pass their alleles on to the next generation. 4. The alleles that lead to the desired phenotype will be inherited by subsequent generations and they can increase in frequency in the gene pool over time.

Answer 490

a process of mating that is not random, but uses parents chosen by the breeder on the basis of particular phenotypic characteristics that they display

Answer 491

can favour features that are disadvantageous for survival and reproduction and would be selected against in the wild (causing difficulty to survive)

Answer 492

- poor hygiene (more bacteria present) - not finishing antibiotic course - over-prescribing of antibiotics

Answer 493

Diseases which could once be treated with a dose of antibiotics can now be life-threatening to individuals with an antibiotic-resistant strain of infection because the bacteria can continue to reproduce in the body.

Answer 494

Antigenic shift occurs when two or more strains of a virus combine to form a new strain of the virus with antigens from each of the original strains.

Answer 495

Antigenic drift is when a point mutation alters a virus’s nucleic material, resulting in small changes to its antigens.

Answer 496

there will be a partial immune response (because of the memory B cells, creating antibodies)

Answer 497

Organism has no memory of pathogen so time will be required for adaptive response (illness is given)

Answer 498

because of antigenic shift and drift occurring changing the genetic material, so the vaccine needs to be changed regularly to combat this

Answer 499

- physical - trace - biosignatures

Answer 500

the remains of all or part of the structures of organisms, such as bones, teeth or leaves

Answer 501

- mineralised fossils - fossils impressions - preserved organism

Answer 502

a physical fossil formed when the organic matter has disappeared but the organism has left an impression of its structure

Answer 503

a physical fossil formed when the organic material of the structure is replaced by minerals

Answer 504

a physical fossil formed when an organism is completely preserved in a substance such as amber, ice or tar

Answer 505

chemical or physical traces that can be inferred to have resulted from the action of life forms

Answer 506

preserved evidence of the activities of organisms, such as footprints, tooth marks, tracks, burrows and coprolite

Answer 507

corrosion pits in rocks caused by chemosynthetic microbes

Answer 508

1. the remains are rapidly buried in sediments after death 2. continued deposits of sediments bury it more and more deeply 3. Over time the rock is eroded, uplifted through the movement of tectonic plates or excavated by palaeontologists so that the fossil is exposed

Answer 509

process of preserving parts of organisms that lived in the geological past

Answer 510

- very cold environment - low oxygen environments

Answer 511

the principle that fossilised fauna and flora in sedimentary rock strata are arranged vertically in a specific order

Answer 512

fossils of geologically short-lived species that are widely distributed but are found in a restricted depth of rock strata

Answer 513

to define a period of geological time

Answer 514

the fossilised remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group

Answer 515

- absolute dating - relative dating

Answer 516

- use of index fossils - use of stratigraphic method (or faunal succession)

Answer 517

radiometric dating technique

Answer 518

the method of obtaining the relative age of an object by its position within a given sequence of rock strata

Answer 519

a technique for obtaining an absolute age that depends on the known rate of decay of a radioactive parent isotope to a stable daughter product

Answer 520

the different forms of an element which differ in the number of neutrons

Answer 521

1. The radioactive isotopes, which can be called ‘parents’, spontaneously decay or break down over time to form stable ‘daughter’ products. 2. The rate of the decay is specific for each radioactive isotope. This is usually measured in terms of half-life, the time taken for half the original radioactive isotope to decay.

Answer 522

carbon-dating

Answer 523

process of formation of new species

Answer 524

the time taken for an amount of radioactive isotope to decay to half of its initial amount

Answer 525

barriers that prevent a fertile offspring developing after mating

Answer 526

- pre-zygotic isolation - post-zygotic isolation

Answer 527

barriers that prevent an organism from finding and securing a mate

Answer 528

- geographic isolation - temporal isolation (active at night or day)

Answer 529

- variation - isolation - selection - genetic divergence

Answer 530

- incompatibility of gametes - sterility of hybrid (hybrid produced is sterile)

Answer 531

when two or more populations accumulate genetic changes, leading them to eventually be reproductively isolated

Answer 532

differences exhibited among members of a population owing to the action of genes

Answer 533

the process in which a variant is more advantageous under certain selective pressures, enhancing its chance of survival and reproduction

Answer 534

1. variation appears in population 2. breeding in population becomes isolated 3. different characteristics emerge (from genetic drift, mutation or environmental pressure) to gain genetic divergence 4. the environment changes and the organisms that are best suited survive 5. survivors reproduce these traits to offspring 6. the frequency of these genes rise 7. the isolated population becomes quite different (new population)

Answer 535

- allopatric - sympatric

Answer 536

speciation that occurs between two populations that are geographically isolated

Answer 537

speciation that occurs between two populations that have no geographical barrier between them

Answer 538

1. physical barrier separates the population (geographically isolated), and no gene flow occurs (begin to mutate differently) 2. different environmental selection pressures appear (different phenotypes being selected by natural selection or genetic drift) 3. over time they become new species and reproductively isolated

Answer 539

Galapagos finches

Answer 540

Howea palms trees

Answer 541

1. population isolated by pre-zygotic isolation barrier (other than geographic isolation, such as temporal or behavioural isolation) and some gene flow occurs 2. Over many generations, genetic divergence occurs. Eventually the isolated populations respond differently to environmental selection pressures 3. change significantly over time. become reproductively isolated and new species

Answer 542

the inability of species to breed and produce fertile offspring

Answer 543

The trees where different in when they flowered Also in the soil they grew in (one prefered volcanic soil)

Answer 544

- structural morphology - molecular homology - biogeography - developmental biology

Answer 545

the process of comparing similarities in body structures to infer relatedness

Answer 546

the process involved in comparing similarities in molecular structures to infer relatedness, with a particular focus on DNA and amino acid sequences

Answer 547

the process of comparing embryos of different species to infer relatedness

Answer 548

geographical distribution of species

Answer 549

structures of organisms that have evolved from a common ancestor to have possible differences in form and function but retain similarities in structure

Answer 550

non-functional structures that are remnants of functional structures in ancestral species

Answer 551

- goosebumps - tailbone

Answer 552

gene or proteins derived from a shared ancestor in which the primary function is conserved

Answer 553

- cytochrome c - haemoglobin

Answer 554

less related, as they have had more mutations to their amino acid sequences

Answer 555

1. direct comparison of DNA base sequences 2. comparison of whole genomes

Answer 556

the comparison of DNA or genes between different species to identify evolutionary relationships

Answer 557

a branching diagram showing inferred evolutionary relationships between life forms based on their observed physical and genetic similarities and differences

Answer 558

the common ancestor of all taxa on a phylogenetic tree (starting point)

Answer 559

- sister taxa - root - branches - nodes - tips

Answer 560

two groups with a common ancestor that is not shared with another taxa

Answer 561

shows an ancestor of two or more descendants on a phylogenetic tree (where the species split)

Answer 562

a section of the phylogenetic tree which indicates a speciation event (coming off the node)

Answer 563

- warm blooded - milk-producing mammary glands - three bones in the middle ear - a lower jaw made of a single bone - fur or hair over their body surface

Answer 564

the terminal point of a phylogenetic tree, representing a particular species

Answer 565

1. kingdom 2. phylum 3. class 4. order 5. family 6. genus 7. species

Answer 566

a group of mammals with opposable thumbs, flat nails and binocular vision

Answer 567

- old world monkeys - new world monkeys - prosimians (lemurs) - apes

Answer 568

- opposable thumbs - flat nails - binocular vision - large brain related to body size

Answer 569

a superfamily of primates that lack a prehensile tail, including apes and humans

Answer 570

- shoulder joints that permit arms to be rotated - distinctive molar teeth in the lower jaw with five cusps - larger and more complex brains - no tail

Answer 571

modern human species and our extinct close relatives that could walk with a bipedal locomotion

Answer 572

a form of locomotion involving routine movement on two feet

Answer 573

- position of the hole (foramen magnum) in the base of the skull - arrangement of the femur and tibia - shape of the pelvis - shape of the spine - size of the heel bone and subsequent heel arch

Answer 574

the angle formed between the femur and the vertical

Answer 575

the centre of the cranium (skull)

Answer 576

a hole at the base of the skull in which the vertebral column attaches

Answer 577

yes between 8 and 11 degrees

Answer 578

more S shaped, compared to C

Answer 579

- Australopithecus - Paranthropus - Homo - Ardipithecus

Answer 580

- increase in the size of the cranium, including the height and the width of the skull, indicating that brain size also was increasing - an increase in the length of feet with more developed arches - an increase in leg length (a larger leg : arm ratio)

Answer 581

- length of the legs (increase) - angle of the legs (bipedal position) - shape of the pelvis (long and narrow) - shape of the foot (flat foot, with curved toes)

Answer 582

DNA located on the mitochondria in cells that is usually inherited maternally

Answer 583

- mtDNA is only inherited by mother, genome is both parents - mtDNA has fewer bases - mtDNA has faster mutation rate

Answer 584

- constant rate of mutation - high copy number per cell

Answer 585

breeding between two species

Answer 586

- more bases (more info) - from both parents so can see if interbreeding occured - introns are there so can reveal more inherited mutations

Answer 587

a region of DNA in the D-loop of mtDNA that varies between individuals

Answer 588

- consequences-based - duties or rules-based - virtues-based

Answer 589

this approach places important on the consideration of the consequences of an action, with the aim to get the most positive outcomes and least negative ones

Answer 590

places importance on the idea that people have duty to act in a particular way (follow the rules)

Answer 591

consideration is given to the virtue or moral character of the person carrying out the action (did they try to do the right thing)

Answer 592

- integrity - non-maleficence - justice - beneficence - respect

Answer 593

commitment for searching for knowledge and understanding that they have to share all their results

Answer 594

moral obligation to ensure that there is fair consideration of all competing claims; no unfair burden on specific group

Answer 595

maximising benefits and minimising risks

Answer 596

involves avoiding the causations of harm

Answer 597

consideration that all living things have intrinsic value (need to consider everything, animals, plants, etc.)

Answer 598

the variable that is changed or manipulated by an investigator

Answer 599

the variable that is influenced by the independent variable and is measured by an investigator

Answer 600

variables that are kept constant across different experimental groups

Answer 601

a statement outlining the purpose of an investigation, linking the dependent and independent variables

Answer 602

a tentative, testable and falsifiable statement for an observed phenomenon that acts as a prediction for the investigation

Answer 603

not fixed or certain, may be changed with new information

Answer 604

able to be proven false using evidence

Answer 605

able to be supported or proven false through the use of observations and investigation

Answer 606

a group that is not affected by the independent variable and is used as a baseline for comparison

Answer 607

how close multiple measurements of the same investigation are to each other

Answer 608

how close an experimental measurement is to a known value

Answer 609

direct or firsthand evidence obtained from investigations or observations

Answer 610

comments on or summaries and interpretations of primary data

Answer 611

data that has labels or categories rather that numberical quantities; also known as categorical data

Answer 612

- nominal - ordinal

Answer 613

a type of qualitative data that has no logical sequence

Answer 614

a type of qualitative data that can be ordered or ranked

Answer 615

numerical data that examines the quantity of something (e.g. length or time); also known as numerical data

Answer 616

- continuous - discrete

Answer 617

a type of quantitative data that can take on any continuous value

Answer 618

a type of quantitative data that can only take on set values

Answer 619

how close the results of successive measurements are to each other in the exact same conditions

Answer 620

how close results are when the same variable is being measured but under different conditions

Answer 621

the consistency of a measurement across multiple trials

Answer 622

credibility of the research results from experiments or from observation; a measure of how accurately and precisely results measure what they are intending to measure through fair testing

Answer 623

- personal - random - systematic

Answer 624

human errors or mistakes that can affect results but should not be included in analysis

Answer 625

chance variations in measurements

Answer 626

errors, usually due to equipment or system errors, that affect the accuracy of a measurement and cannot be improved by repeating an experiment.