1 2<html> 3<head> 4<title>BioTopics Website - Main Index Front Page</title> 5<!-- Website Created on August 19, 2002 --> 6<meta http-equiv="Content-Type" content="text/html;charset=utf-8"/> 7<meta name="author" content="Richard Steane"/> 8<meta name="keywords" content=" Biology revision, GCSE Biology, dual award science, key stage 4 science, KS4, Edexcel, AQA, OCR, GCSE worksheets, AS Biology, A2 Biology, A level Biology, self supported study, study guides, teaching resources, tutorials, online courses, Biology, revision, Steane, BioTopics, Biological topics, howlers, humour, agaricologism, assessment, mouseover reveal, interactive text, animations, 3D molecules, biological chemicals, biochemicals, Jsmol"/> 9<meta name="description" content="An interactive web-based Biology resource including teaching/learning notes for GCSE and AS/A level Biology (Key Stage 3 4 + 5 of the UK National Curriculum) as well as interactive 3-D biological molecules"/> 10<meta name="viewport" content="width=device-width, initial-scale=1"> 11<link rel="toc" href="conten.html"/> 12<link rel="shortcut icon" href="favicon.ico" type="image/x-icon"> 13<link rel="canonical" href="https://www.biotopics.co.uk/index.html"/> 14<!-- Global site tag (gtag.js) - Google Analytics -->
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33<script language="JavaScript" type="text/javascript">var compliments=new Array("A really good website explaining everything you need to know in a way everyone can understand","I have been very impressed with your site and have used it to improve my own knowledge to update it in the lastf year while I was doing my PGCE","I have recently found your website - It is very useful and I shall be recommending it to my students - Just wanted to say thanks for your time","I have never come across such a creative, marvellously organized website. It is outstanding","Its really an excellent site for students as well as teachers information . So being as a human being and biology teacher I want to say u thanks for making such a wonderful resourceful site as guide line in general","Would be better if there is MC questions as well - but overall this is a VERY VERY useful site for revision","Thanks for this website: very useful indeed since there are not really many notes on the extension bit!","Having been a professor for many years...as well as a student for many years prior...I really appreciate the dedication and teaching savvy your site demonstrates. My field is ed tech....and I can only hope more professors move beyond their fears of technology and embrace the potential of multimedia instructional tools","I am not a specialist science teacher and have to learn before I teach - found this very useful for GCSE (p.s - also used for my daughters coursework - worked well) Thanks","I would like to thank you for the site that you created. I am a GCSE student and
33your site provides suberb information for revision and has been a valuable asset","This was the first time I had encountered your website and I was impressed to see how easy it was to find the information relevant to me. Thankyou","I was particularly attracted to your comprehensive but clear designs of cells and easy to understand explanations","So much relevant information. I wish I had found it sooner","I loved the website and spent a lot longer than I really thought on it as I became hooked with all the interesting information","My compliments on an excellent website! It is well designed and easy to follow. It is great to see an interactive site where one has to scroll over the spaces to get the answers","I am writing to you as I am currently studying a part time access course to university, with human biology as my first module. I am enjoying looking at the spinneret site","Thank you so much for taking the time to make the website interactive. The interactivity really aided in my comprehension of the material. There are very few resources of this type for Biology on the World Wide Web. Yours is exceptional!!","Your website is great","I am an A-level student student currently studying Biology, Chemistry and maths. I find your web site very helpful and interesting.Thank you!","I just wanted to tell you that your site has been truly useful for my daughter and for me to help her with her revision. You have done a wonderful job of making the subject not only interesting but extremely easy to understand.","I found this site extremley helpful, especially as I have only just started doing my degree and am struggling with some of the concepts. The question and answer sections are very helpful and I feel I understand each concept a little more than before. Thank you","I think this is a fantastic site for students trying to study for a test or just surfing around to learn something new. I hope that you continue developing this site, with more info, theory, examples, etc. Great job so far!","Thank you very much! The site is great! More mouse overs which give answers would be great. It's a wonderful method to test if I know what I'm doing...","I just want to thank you for taking the time to make this web page... The information will help me ever so much in getting the kids to understand the concepts....A concerned new teacher.","I am a student studying biology at as level, and I found this page very helpful, thank you very much.","I love your website. I was just looking for a diagram or description of a fructose molecule and accidentally stumbled on your pages, which are so clear and well organized","Your website has proven to be a great assistance to me as I prepare my twelth grade students to sit the GCSE biology exam","helpful site here","this site would certainly help clarify some basics concepts very effectively","extremely useful website for biology. very helpful for tests and exams","many thanks for your website: the howlers were absolutely brilliant. I have not laughed so much in ages","This is the best site I've had the pleasure of coming across for biological information delivered in extremely clear concise and to-the-point accuracy."," The untold hours of research and information-gathering that have obviously gone into your site, not to mention the excellent (and intriguing) mouse-overs and animation are much appreciated.","Thank you again for access to this very excellent site!","i would just like to say that your website is really good, its really helped me do my work. thankyou","i am teaching students and i find your website very useful especially the diagrams","may i take time to say how much this website has helped my son","the best interactive online notes for GCSE biology on the web","This is a great site. It's simple and easily understood by students of intermediate knowledge in the Bioprocess fields.","Contains some of the most common, but essentail topics that a student would need to recall/enchance their knowledge learn in the theory lesson. Though further animations can be included, this is overall bravo.","an excellent source of pertinent biology resources.","Thank you for putting in into a simple language for me to understand. Antibodies now make sence to me ","As a teacher of Biology I find your website informative and extremely useful - it is incredibly precise and manages to get exactly the right balance of detail and ease of access","This is a good website to go on to find out info on enzymes","What an excellent website. Love the use of color, the way you scroll to see the answer, photos, etc. DId a really great job. Far and above all others.","All most all the information are very accurate and important and the way you have design your web page is very attractive","This is so informative! It makes my reserach work become easier than ever. I used this 4 my presentation/reporting in school","Your information is vital to us young and willing to learn b
33iologists","A very informative site for teachers teaching I.G.C.S.E.curriculum","Thanks for the comprehensiveness","I find this an excellent website and has everything you need for GCSE and A level Biology as I am studying an Access Course I find it very useful","your notes are laid out in perfect order. I have found it so much easier to revise efficiently!","The entire sylabus is covered in the detail i need. The information provided is excellent","This is exactly what i needed as i have missed over 3 months of school","This infomation is great, well written, and easy to understand.","The site is excellent","my class is using your website as an adiitional place to learn more abot biology as well as having a great time","we hope you continue to improve your fabulous site","Great site. I intend to refer my .. clients to it.","thank you this information has helped me with my course work","This website is kind of ddepenndable . Thannks .","I think this websites is usefull to me and i think i can get a wonderful grade if i continue to use this website as a reference.","It is really difficult to find something that will actually help me with my work, and this did! thanks again","Just discovered this site, it looks very usefull! Thanks.","this site ... has helped me to do a lot of my previous home works","nice website, thanks for making us do loads of work in class. it was fun and es[pecially fun for em beacause i love science!!","this helped us with my daughters homework - thankyou!","This website has really helped me with my coursework. Thanks a lot. It's easy to use and appealing. Very good job!","These notes are fantastic and so appreciated! They are helping me through my Biology GCSE.","thanks so much...this is an awesome page to study for my tests. KEEP DOING WHAT U DO","Very good topics covered - worth browsing - easy to understand and well presented. 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The rollover mouse thing is simple but ingenious and these web pages really help me revise for Bio GCSE.","i would like to say a very big thank u as u guys helped me so much in my IGCSE biology and i'm happy to tell u that i managed A* because of u!!!!"," I absolutely love this site. It is very interesting and informative and as a nursing student it has really helped me. I will definitely pass this page on to my colleagues.","Keep up the good work and dont close this site. EVER","I have enjoyed your notes on various topics. They have good basic knowledge on science topics"," i liked all your information. i got an A+.so thanks for all your help.","Thank you very much for assembling this information!!","It's especially helpful to be able to rotate the molecules for a better look at the structure. 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33ing the jmol versions to jsmol","Thanks so much for your work on updating the 3D structures of molecules page to JSMol and HTML5. I use your pages in my non-science majors courses, and it is very helpful!","Thank you so much for creating this website and putting in so much effort! It is excellent, even as a website it is easy to see the passion you have for your subject. Oct26 ");var complimentsCt=compliments.length;{{randomNum=Math.floor((Math.random()*complimentsCt));var statement=compliments[randomNum];}}</script>
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34<script language="JavaScript" type="text/javascript">var howlerpics=new Array("Female mammals have memory glands.","Eggs pass down the oval duct.","Lobotomy - the study of plants.","Biomass - the mass of an organism excluding the bone.","The small bones in the ear are called icicles.","The population rose because less were dying due to improvements in medicine.","Animals that eat grass only have one set of incisors at the bottom.","When the woman goes into labour, a housewife helps.","In the light our eyes can be smaller.","Water provides a habit for aquatic organisms.","Soon the mother will get the ultimate pain and out will pop the baby.","A lactating woman is one who beast feeds.","Means of preventing malaria: take precautions at night.","A smoker's lungs are clogged up with alveoli.","The action of the earthworms keeps the earth turning.","In diabetes the prostate gland does not produce any insulin.","After fertilisation 2 gametes join together and decide vital factors about the child.","In dark light the pupil gets bigger.","The rib cage prevents the lungs from expanding beyond a certain point.","There are three bees in a colony.","For a woman to become pregnant she must become fertilised. This is done with a male present.","When a chicken is killed it does not totally die because <i>Salmonella</i> are still alive in its guts.","The calf had a parent which was a pure bull.","In this investigation I didn't get any anonymous results.");var howlpicCt=howlerpics.length;{{randomNum=Math.floor((Math.random()*howlpicCt));var chosenhowl=howlerpics[randomNum];}}</script>
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95 96 97</head> 98<body bgcolor="#ccffcc"> 99<div class="section group"> 100 101 102 <div class="col span_1_of_3"> 103<!-- TOP LHS --> 104 <div align="left"> 105 <img src="data:image/webp;base64,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" border="0" style="width:250 px;" alt="www.BioTopics.co.uk" name="bio" title="The BioTopics home page"/> 106 <!-- style= "width:60%;"--> 107<div class="disposable2" style="font-size: 12px; font-size: 1.3vw;" title="If you find this useful, please acknowledge BioTopics.co.uk and if necessary me personally"><font color="#0000ff"><font face="Verdana,Arial">Site author Richard Steane</font></font> 108</div> 109</div> 110 111 112 </div> 113 <div class="col span_1_of_3"> 114 115 <!-- TOP CENTRAL --> 116 <div class="disposable2"> 117 <div align="center" style="font-size: 12px; font-size: 1.3vw;" title="Use your mouse to move the cursor over the text and graphics in the section below. Look out for explanatory tooltips (drop-down text boxes) as well as other information"> 118<font face="Verdana"> 119 The BioTopics website gives access to interactive educational resource material, developed to support the learning and teaching of Biology at a variety of levels. 120<br/> 121<br/> 122<div><font color="#0000ff">1.39 million pages downloaded in 2025</font></div><div></div> 123 </font></div> 124 </div> 125 </div> 126 <div class="col span_1_of_3"> 127 128 <!-- TOP RHS --> 129 <div class="disposable" align="center" title="Google custom search on the BioTopics site"><!-- RHS section - search box --> 130 131 132 <!-- Biotopics2 Search engine --> 133
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133 134<gcse:search></gcse:search> 135 136 </div> 137 </div> 138</div> 139 140<!-- DROPDOWN MENU START 141 now included in heading 142--> 143<div id="menuh-container"><!-- title="The main Biological Topics" --> 144<div id="menuh"> 145 146<ul><!-- menuheadings --> 147 <li><a href="#" class="top_parent" onmouseover="loadXMLDoc('list1','../navlists/list1.txt')">Introductory Topics</a><!-- top parent li .. /li later --> 148 <!-- AJAX here --><div id="list1"> <!-- Div gets replaced --> 149 <ul><!-- dropdown --> 150 <li><a href="conten.html" title="Click here for a full menu of BioTopics contents in table form">FULL CONTENTS</a></li> <!-- (Menu) link remains if no Ajax, e.g. local file --> 151 </ul><!-- dropdown --> 152 </div> 153 </li><!-- top parent li .. /li later --> 154</ul><!-- menuheadings --> 155 156<ul> 157 <li><a href="#" class="top_parent" onmouseover="loadXMLDoc('list2','../navlists/list2.txt')">Classical Topics</a> 158 <div id="list2"> 159 <ul> 160 <li><a href="conten.html#originalGCSEstart" title="Contents page - 161 Second (grey) column">Humans, Plants<br>Variation, Ecology</a></li> 162 </ul> 163 </div> 164 </li> 165</ul> 166 167<ul> 168 <li><a href="#" class="top_parent" onmouseover="loadXMLDoc('list3','../navlists/list3.txt')">Further Topics</a> 169 <div id="list3"> 170 <ul> 171 <li><a href="conten.html#extensions" title="Contents page - 172 Third column">Microbes Section</a></li> 173 </ul> 174 </div> 175 </li> 176</ul> 177 178<ul> 179 <li><a href="#" class="top_parent" title="Mostly AS and A level" onmouseover="loadXMLDoc('list4','../navlists/list4.txt')">Higher level Topics</a> 180 <div id="list4"> 181 <ul> 182 <li><a href="conten.html#AandAS" title="Contents page - 183 Fourth column">A/AS level Section</a></li> 184 </ul> 185 </div> 186 187 </li> 188</ul> 189 190<ul> 191 <li><a href="#" title="Interactive movable molecules - 192 New format - no security risk" class="top_parent" onmouseover="loadXMLDoc('list6','../navlists/list6.txt')">3D molecules [Jsmol]</a> 193 <div id="list6"> 194 <ul> 195 <li><a href="jsmol/jscontents.html" title="This takes you to a menu that is separate from the main Biological Topics">MOLECULES MENU</a></li> 196 </ul> 197 </div> 198 </li> 199</ul> <!-- bottom --> 200</div> <!-- end the menuh-container div --> 201</div> <!-- end the menuh div --> 202 203<!-- DROPDOWN MENU END--> 204 205<div class="section group" title="Main sections of the BioTopics website 206Each section leads to a menu of its own" style="background-color: #99FF99; font-weight: bold; text-align: center;"> 207<div class="disposable2"> 208 <div class="col span_1_of_3"> 209 <span title="The main section: BioTopics pages">Biological Facts</span> and <span title="Howlers are Biological misconceptions">Fallacies</span> 210 </div><!-- col span_1_of_3 --> 211 <div class="col span_1_of_3"> 212 <span> 213 214 Last modification 01/10/2026 215 </span> 216 </div><!-- col span_1_of_3 --> 217 <div class="col span_1_of_3"> 218 Biological Chemicals and Supplies 219 </div><!-- col span_1_of_3 --> 220 </div> 221</div> <!-- "section group" --> 222 223 224<div class="section group"> 225 <div class="col span_1_of_3" onclick="window.location ='conten.html'" style="cursor: pointer" title="More than 2 million pages are now being downloaded per year from this website!"> 226 <!-- LHS TOP BOX --> 227 <div align="center"> 228 <a href="conten.html" title="Click to go to Biological Topics Contents Page"><img src="topics.gif" class="left" alt="Biotopics units" align="top" border="0"/> 229<!-- width="190" --> 230 231 232<br/> 233<font face="Gill Sans MT" size="3"><b>Click here to visit the Biological Topics Contents Page 234<br><span title="I had not updated this number, but it certainly has crept up over time!"> (currently 259 topics)</span></b></font></a> 235<br/> 236<i title="Some users have misunderstood the format - the gaps are to assist your comprehension in a tutorial style"><b>Interactivity</b> is key to most of this material. Don't forget to run the cursor over any gaps in the text, coloured text, unlabelled diagrams and other links in the text or margin...... <a href="interactiveinnovations3.html" title="Just click ..."> 237<br/>More explanation about these features</a> is available.</i> 238<br/> 239
240<script language="JavaScript" type="text/javascript">document.write('<h4><font color="#008000" title="More than 60 unsolicited recommendations ...">What other visitors have said about this material:</font></h4>');document.write('<font face="sans-serif" color="#008000" title=" ... You should see a new comment each time you visit this page - but I have put these comments in the original format including odd spellings etc">'+'"'+statement+'"'+'</font>');</script>
240 241 242 243</div> 244 245 246 </div><!-- col span_1_of_3 --> 247 <div class="col span_1_of_3" style="background-color: #BBEEFF;"> 248 249 <!-- CENTRAL SECTION --> 250 251<center> 252<h3 title="All sections of the AS specification are now covered">Most recent material <span title=" I hope you appreciate the division into basic information on the left-hand column, and extension material on the right-hand side"> - AS and A level topics 253</span></h3> 254 255<b style="background-color:blue;color:white">. Now covers all the AQA specification - 58 sections .</b> 256<br/> 257<a href="Background.html">Background information on these higher level topics</a> 258<br/> 259<b><i title="Mouseover for more detail">Click on the categories below to expand/contract</i> </b> 260<br/> 261 262 263<b>AS</b> 264 <a href="javascript:expandcontract('biolchem')"> 265 <span title="These feature mouseover effects for extra detail and some have further spoken explanations"><i><b>Biological Chemicals</b></i></span></a> ... 266 267<span id="biolchem" style="display:none"><a href="A15/Monomers_and_polymers.html" title="Some underlying biochemical principles, condensation and hydrolysis applicable to the next few topics">Monomers and polymers</a> ... 268<a href="A15/Carbohydrates.html" title="Monosaccharides, disaccharides, polysaccharides">Carbohydrates</a> ... 269<a href="A15/Lipids.html" title="Fats and oils, phospholipids">Lipids</a> ... 270<a href="A15/Proteins.html" title="Amino acids, Similarities and differences, Plant & animal proteins, Levels of protein structure">Proteins</a> ... 271<a href="A15/water.html" title="The Biological Significance of Water and molecular explanation">Water</a> ... 272<a href="A15/Enzymes.html">Enzymes</a> ... 273<a href="A15/pH.html">pH</a> ... 274<a href="A15/ATP.html" title="Adenosine triphosphate">ATP</a> ... 275<!-- missing DNA structure! --> 276<a href="A19/Nucleic_acids.html" title="Information-carrying molecules 277(DNA and RNA) 278Nucleic acids are polymers of nucleotides 279Nucleotides join to form longer molecules 280A DNA molecule is composed of two long polynucleotide chains 281An RNA molecule is comparatively short 282Mathematical certainties? 283Getting things in proportion 284Long-term versus short-term 285Ribose and deoxyribose - possible bonding sites 286Why uracil in RNA, but thymine in DNA? 287Nucleotide nomenclature 288Pairings of nucleotides in DNA 289Comprehension test">Nucleic Acids</a> ... 290 291<a href="A15/DNA_replication.html" title="How DNA is copied">DNA replic<sup>n</sup></a> ... 292<a href="A15/Inorganic_ions.html" title="mineral salts, electrolytes, hydrogen ions, iron ions, sodium ions, phosphates">Inorganic ions</a> 293</span> 294 295 <a href="javascript:expandcontract('cells')"> 296<i title="OK I tweaked that title a bit ... "><b>Cells and cellularity</b></i></a> 297<br/> 298<span id="cells" style="display:none"> 299 300<a href="A15/Eukaryotic_cells.html" title="Some nice images">Eukaryotic cells</a> ... 301<a href="A15/Prokaryotic_cells.html" title="Some more nice images">Prokaryotic cells</a> ... 302<a href="A15/studying_cells.html" title="loads of good images and some mouseover tables for comprehension tests">Studying cells (with the microscope)</a> ... 303<a href="A15/Virus_particles.html" title="I am pleased with these images too">Virus particles</a> ... 304<a href="A15/Endosymbiont_theory.html" title="Some thought-provoking stuff linking prokaryotes and eukaryotes">Endosymbiosis</a> ... 305<a href="A15/Transport_across_cell_membranes.html" title="Eukaryotic cell membrane structure, phospholipids, proteins, glycoproteins, glycolipids, the fluid mosaic model, simple diffusion, facilitated diffusion, osmosis, active transport, co-transport, adaptations for rapid transport across membranes">Transport across cell membranes</a> ... 306<a href="A19/cell_cycle.html" title="Interphase, G1,S,G2, Mitosis, Behaviour of chromosomes, kinetochores and the spindle, prophase, prometaphase, metaphase, anaphase, telophase, Cytokinesis, Cancer, chemotherapy, Binary fission in prokaryotic cells, viral replication, ">The cell cycle</a> ... 307<a href="A19/Cell_recognition.html" title="Cell recognition, the interaction between antigens and antibodies, the immune response, vaccination, HIV, and monoclonal antibodies">Cell recognition</a> 308</b></span> 309 310<a href="javascript:expandcontract('exchanges')"><i title=""><b>Exchanges with the environment</b></i></a> 311<br/> 312
313<span id="exchanges" style="display:none"> 314<a href="A20/Surface_area_to_volume_ratio.html" title="Single-celled organisms vs multicellular organisms 315Surface area to volume ratio 316Cells getting together 317Getting longer 318Staying flat 319Getting specialised 320All systems go 321Metabolic rate 322If only cells were cubes 323Spherical objects, real units 324Bergmann's rule">Surface area to volume ratio</a> 325. . . 326<a href="A20/Gas_exchange.html" title="Gas exchange surfaces 327Gases must dissolve before they can be exchanged 328The (body?) surface of a single-celled organism 329The tracheal system of an insect 330The gills of fish 331The leaves of dicotyledonous plants 332Specialisation for terrestrial environments 333Terrestrial insects 334Xerophytic plants 335The human gas exchange system 336The bronchial tree and factors affecting flow in the airways 337Structure of an alveolus 338The mechanism of breathing (how we breathe in and out) 339Conditions affecting the functioning of the respiratory system 340Pulmonary ventilation rate (PVR), tidal volume and breathing rate 341Respiratory quotient (RQ) (from the sublime to the ridiculous) 342The use of a simple respirometer to measure volumes of gases involved in gas exchange">Gas exchange</a> 343 . . . 344<br/> 345<a href="A20/Digestion_and_absorption.html" title="The digestion process 346Digestion of carbohydrates 347Polysaccharides (carbohydrate polymers) 348Oligosaccharides (mostly carbohydrate dimers) 349Digestion of proteins 350Polypeptides 351Dipeptides 352Digestion of lipids 353Absorption of the products of digestion 354Absorption of amino acids and of monosaccharides 355Micelles and chylomicrons in the absorption of lipids">Digestion and absorption</a> 356 . . . 357 358<a href="A20/Mass_transport_in_animals.html" title="Mass transport: a delivery system for lots of molecules 359Haemoglobin 360The role of haemoglobin and red blood cells in the transport of oxygen 361Inside the lungs, the circulation, the tissues 362Oxyhaemoglobin Dissociation curve 363The cooperative nature of oxygen binding 364Effects of external factors on the dissociation of oxyhaemoglobin 365Carbon dioxide concentration (the Bohr effect) 366Temperature 3672,3 BPG 368Different types of haemoglobin with different oxygen transport properties. 369Fetal and maternal haemoglobin 370Large and small mammals 371High altitude vs low altitude 372The general pattern of blood circulation in a mammal 373Structure of the human heart, and events within the cardiac cycle 374Arteries, arterioles, (venules) and veins 375Structure of capillaries 376Formation of tissue fluid">Mass transport in animals</a> 377<br/> 378 379<a href="A20/Mass_transport_in_plants.html" title="Mass transport: two delivery systems for molecules 380Xylem 381Cells involved 382The main driving force in the uptake of water is a pull from above 383Roots give a small push from below 384Cohesion-tension - not just a theory 385Phloem 386Cells involved 387Translocation of sucrose by mass flow under pressure 388Heat and chemical treatments 389Summary of differences 390Evidence for cohesion-tension 391A classic ringing experiment 392Single leaf labelling with CO2 radioisotope to trace translocation of photosynthate 393">Mass transport in plants</a> 394 395 </span> 396 397 398 <a href="javascript:expandcontract('geninfo')"> 399<i title="also Variation and relationships between organisms"><b> Genetic information</b></i></a> 400 401<span id="geninfo" style="display:none"> <a href="A20/DNA_genes_and_chromosomes.html" title="DNA - different types in different places 402Prokaryotic cells - no loose ends 403Eukaryotic cells - all wound up 404Mitochondria and chloroplasts - keeping their own information safe 405Viral DNA and RNA - putting it about 406What is a gene? 407The genetic code is not a secret (any more) 408Non-coding DNA 409The genetic codes for each amino acid 410Coding for degeneracy 411ORFs - another way of defining genes (and finding them)">DNA, genes and chromosomes</a> 412 . . 413<a href="A20/DNA_and_protein_synthesis.html" title="Transcription 414Similarities with DNA replication 415Exons, introns and splicing 416Translation 417More about ribonucleic acids:mRNA, tRNA 418Connecting each tRNA with its amino acid "> 419DNA and protein synthesis</a> 420 . . 421<a href="A20/Genetic_diversity.html" title="Genetic diversity and uniformity 422Gene mutations 423Mutagenic agents 424Base deletion 425Consequences of base deletions 426Base substitution 427Not all base substitutions cause a change 428Differences in the number of chromosomes 429Meiosis does more than halve chromosome number 430Meiosis results in genetic variation 431Comparison of meiosis with mitosis 432The genetic code 433Life cycles 434The life cycle of a fern "> 435Genetic diversity</a> 436 . . 437<a href="A20/Genetic_diversity_and_adaptation.html" title="Genetic diversity in a population 438Natural selection acts upon genetic diversity 439The principles of natural selection in the evolution of populations 440Species are seen to be adapted to their environment 441Changes in allele frequency "> 442Genetic diversity and adaptation</a> 443 . . 444<a href="A17/Species_and_taxonomy.html" title="24 examples classified! Groups within the standard phylogenetic classification system, The bottom line (or two), Putting names to all the categories, Names behind the naming system, How many domains? How many kingdoms?">Species and taxonomy</a> 445 . . 446<a href="A15/Biodiversity.html" title="Species richness, Species abundance, Index of diversity together with some example calculations, and thoughts about reduction of biodiversity as a consequence of certain farming techniques and the balance between farming and conservation, as well as friends and enemies of Biodiversity"> Biodiversity within a community</a> 447 . . 448<a href="A20/Investigating_diversity.html" title="Comparing diversity 449Reasons for making comparisons 450Encouraging genetic diversity 451Discouraging interbreeding 452Quantitative investigations of variation 453Mean and standard deviation 454Other sampling statistics 455Sorting out your giraffes 456Identifying Scottish Wildcats 457Investigation of genetic diversity in different breeds of dog"> 458Investigating diversity</a> 459 </span> 460 461 ... 462 463 <br/> <b>A2</b> 464 <a href="javascript:expandcontract('energy')"> 465<i title="In and between organisms"><b>Energy transfers</b></i></a> 466 467 <span id="energy" style="display:none"> 468 469 470<a href="A17/Respiration_processes.html" title="Respiration and energy, Acids and bases, Glycolysis, Anaerobic respiration, The link reaction, The Krebs cycle, Electron transfer chain, Balancing the equation, Respiration and oxygen, Glycolysis in more detail, Consequences of anaerobic respiration, Ins and Outs of mitochondria, The link reaction in more detail, One cycle, three names, Et Cetera Et Cetera, Accounting for protons, and energy">Respiration processes</a> 471 . . . 472<a href="A17/Photosynthesis_reactions.html" title="The light-dependent reaction, The LDR in more detail, Photosystem II, Photosystem I, Photophosphorylation, Cyclic photophosphorylation, The Hill reaction, The light-independent reaction, The Calvin cycle, The LIR in more detail, Carbon dioxide fixation, Reduction, Regeneration of RuBp, Photorespiration - the downside of RuBisCO, Evolution of photosynthesis, Environmental factors that limit the rate of photosynthesis, Experiments to investigate the effect of environmental variables on the rate of photosynthesis, Chromatography of photosynthetic pigments, Common agricultural and horticultural practices used to overcome the effect of these limiting factors">Photosynthesis reactions</a> 473. . . 474<a href="A19/Energy_and_ecosystems.html" title="Energy and ecosystems, Plants, photosynthesis, production, planet Earth, Measuring biomass and chemical energy, Dry biomass, Mass of carbon in biomass, Using calorimetry to measure chemical energy, Biomass in power generation, Primary production - by Plants, Gross primary production, (GPP), Net primary production (NPP), NPP = GPP - R, Biomass transfer to consumers, N = I - (F + R), N = I - F - R, secondary production, Farming practices and agricultural production">Energy and ecosystems</a> 475. . . 476<a href="A19/Nutrient_cycles.html" title="Nutrients are recycled within natural ec
476osystems 477Saprobiotic nutrition 478The nitrogen cycle 479Inorganic nitrogen compounds 480Organic nitrogen compounds in plants 481Organic nitrogen compounds in animals 482Decomposition of organic nitrogen compounds in plant and animal wastes, and dead plants and animals 483The role of bacteria in the nitrogen cycle 484Ammonification 485Nitrification 486Nitrogen fixation 487Non-biological nitrogen fixation 488Biological nitrogen fixation 489The reduction of nitrogen 490In Biology, not all vegetables are legumes 491The establishment of root nodules 492Other symbiotic associations 493Other nitrogen fixers 494Symbiotic 495Free-living 496Denitrification 497The phosphorus cycle 498Inorganic phosphates - not quite so simple 499Organic phosphates 500Mycorrhizae 501The answer lies in the soil 502Crop rotation 503Natural fertilisers 504Taking the urine? 505Urea - a compound that changed our thinking about the chemistry of life 506Artificial fertilisers 507Weapons take priority 508Hydroponic growing 509Environmental issues arising from the use of fertilisers 510Leaching 511Washday problems 512Eutrophication">Nutrient cycles</a> 513</span> 514 . . 515 <a href="javascript:expandcontract('response')" title="Nerve and muscle cells and regulation of body conditions"> 516<i><b>Response... </b></i></a> 517 518<span id="response" style="display:none"> 519<a href="A19/Survival_and_response.html" title=" Survival tactics, Flowering plants and tropisms, Nice or nasty?, Background, experimentation on planr growth responses, Indoleacetic acid (IAA), Other phytohormones, Shoots, Auxin movement - sideways and down in shoots, Roots, The fall and rise of auxin in roots, Taxes, Fine-tuning the response, Kineses, Choice chambers, Animal antics, Bacteria too, The simple reflex, Other reflex actions">Survival and response</a>, 520 521 522<a href="A17/Receptors.html" title="The structure of a Pacinian corpuscle, The human retina, photochemistry, Layers of cells in the retina, With sensory neurones, an ending is just the beginning, Finger pinching, with wires attached, All in the back of the eye, colour blindness ">Receptors</a>, 523<a href="A17/Control_of_heart_rate.html" title="Receptors in the circulatory system, Within the heart, Hearts don't just beat faster ... , ECG starting with P">Control of heart rate</a>, 524 525<a href="A17/Nerve_impulses.html" title="Structure of the neurone, The nature of nervous impulses along the axon, resting potential, Action potential, factors affecting the speed of nervous conduction, Myelination, Axon diameter, Temperature, Types of neurones, How a Schwann cell myelinates (part of) an axon, Stimulation of an axon, The sodium/potassium ion pump">Nerve cells, impulses</a> , 526<a href="A17/Synaptic_transmission.html" title="Types of synapse, acetylcholine, acetylcholine esterase, neurotransmitter substances, acetylcholine esterase inhibitors, organophosphate insecticides, nerve gases, nerve agents, synaptic interactions between neurones, progress of nervous impulses, Unidirectionality, Temporal summation, spatial summation, inhibitory synapses, Effects of specific drugs on synapses, neuromuscular junction, effects of specific drugs ">Synaptic transmission</a> , 527<a href="A17/Skeletal_muscle.html" title="Muscles work by shortening, Muscles work in pairs - and take it in turns, Structure of skeletal muscle, Gross structure, Finer structure, Microscopic structure, Ultrastructure of a myofibril, Getting the process started, Myofibril contraction, Actin-Myosin cycle, The processes behind muscle power, ATP and phosphocreatine in muscle contraction, Slow and fast skeletal muscle fibres, The arm as a lever, Other types of muscle, More illuminating names for the different areas of a sarcomere, Working in from the outside, Proteins on the pull, Actin, Myosin, Accessory proteins, An M word, G words, Not to be confused with .., Creatine as a supplement">Skeletal muscle</a>, 528<a href="A19/Homeostasis.html" title="Maintenance of a stable internal environment, physiological control systems, pH control, acid-base homeostasis, Temperature control, Thermoregulation, stable blood glucose concentration, Osmoregulation, Negative feedback restores systems to their original state, Inputs and outputs, Keeping things in proportion, Positive feedback">Homeostasis</a>, 529 530<a href="A19/blood_glucose_control.html" title="Glucose is fuel - so it must not run out 531Storage of surplus glucose 532Getting more glucose back into the bloodstream 533Summary of activity of insulin and glucagon 534The second messenger model 535Diabetes mellitus 536Type 1 diabetes 537Type 2 diabetes 538Hypogycaemia, hyperglycaemia 539Measuring the concentration of glucose in blood 540and more">Control of blood glucose concentration</a> 541 542<br/> 543 <a href="A19/blood_water_potential_control.html" title="
544Balancing the aqueous inputs and outputs 545ADH production and release 546Formation of glomerular filtrate 547Reabsorption of glucose and amino acids 548(with sodium ions and water) from the proximal convoluted tubule 549It all gets concentrated outside of the loop of Henle 550The last movement of ions in the distal convoluted tubule 551Fine-tuning the reabsorption of water under the control of ADH 552Blood sweat and tears . . . 553What not to do after a marathon 554The problem with salt">Control of blood water potential</a> 555</span> 556 557<a href="javascript:expandcontract('evolution')" title="Lots of examples"> 558 559<br/> 560 <i><b>Genetics, Evolution & speciation</b></i></a> 561<br/> 562<span id="evolution" style="display:none"> 563<a href="A20/Inheritance.html" title="Genetics 564Genotype and phenotype 565Alleles 566Types of crosses 567Genetic diagrams 568Example crosses using fruit flies 569Monohybrid crosses 570Dihybrid crosses 571Sex linkage 572Autosomal linkage 573Chi-squared test 574Calculation of chi-squared 575Monohybrid cross 576Dihybrid cross 577Dihybrid cross- with linkage 578Examples using plants 579Crossing red with white 580Human blood groups 581The ABO series 582Colour blindness in humans 583Non-mendelian ratios 584Epistasis 585Lethal genes"> Inheritance</a>, 586<a href="A20/Populations.html" title="Populations and genetic dynamics 587Frequencies within a population 588Allele frequency 589Genotype frequency 590Phenotype frequency 591The Hardy-Weinberg principle 592Applying the Hardy-Weinberg equation 593Examples 594Heathland flowers
595Phenylketonuria (PKU) 596Multiple alleles 597Heterozygote Advantage 598Sex-linked genes">Populations</a> 599<!-- also in info - not rewritten/replaced --> 600 , 601 602<a href="A17/Evolution.html" title="Definition + more to be added"> Evolution processes</a> , 603 604<a href="A17/Sympatric_speciation.html" title="Definition + Examples: Spartina cordgrass- A recent discovery, (Monkeyflowers), Not quite a new species, Christmas cactus and Easter cactus, Palms of Lord Howe Island"> Sympatric Speciation</a>, 605<a href="A17/Allopatric_speciation.html" title="Definition + Posssible examples: Fauna of the Galapagos Islands: Darwin's finches, Galapagos giant tortoises, Not quite giants (St Kilda Wren + Field Mouse), Californian pupfish, Anolis lizards in the Caribbean and USA, Zebras, Giraffes"> Allopatric Speciation</a>, 606<a href="A17/Populations_in_ecosystems.html" Title="Ecological terms, Estimating population size using quadrats and transects, Mark-release-recapture method, and Succession with examples from Surtsey and Sand dune succession">Populations in ecosystems</a> 607 608</span> 609 610<a href="javascript:expandcontract('geneexpression')" title="Follows on from some AS topics"> 611<i><b>The control of gene expression</b></i></a> 612<br/> 613 614<span id="geneexpression" style="display:none"> 615 616<a href="A20/Base_sequence_alteration.html" title="Alteration of the sequence of bases in DNA can alter the structure of proteins 617Gene mutation 618Addition 619Deletion 620Substitution 621Transitions 622Transversions 623Inversion 624Duplication 625Translocation 626Mutagens and mutation rate 627Not all mutations result in a change 628Downstream changes">Base sequence alteration</a> 629<br/> 630 631<!-- <a href="" title=""></a> --> 632<a href="A20/Cell_potency.html" title="Most of a cell's DNA is not translated 633(potency varies from cell to cell) 634 635Turning on and turning off genes - for positive and negative outcomes 636Totipotent cells 637Pluripotent, multipotent and unipotent stem cells 638Stem cells for meat products 639Induced pluripotent stem cells (iPS cells) 640Use of stem cells in treating human disorders 641Ethical issues 642Cells' potential varies 643Triploblasty 644">Cell potency</a> 645<br/> 646<a href="A20/Regulation_of_transcription_and_translation.html" title=" Targetting a gene to be transcribed 647Transcriptional factors 648The role of oestrogen in initiating transcription 649Epigenetic control of gene expression 650Methylation of DNA 651Acetylation of histones 652Epigenetics and the development and treatment of disease, especially cancer 653RNA interference (RNAi) 654 655Post-transcriptional gene silencing">Regulation of transcription and translation</a> 656<br/> 657<a href="A20/Gene_expression_and_cancer.html" title="Benign and malignant tumours 658Tumour suppressor genes 659Oncogenes 660Breast cancer 661The effects of oestrogen on breast cancer 662BRCA1 and BRCA2 genes 663TP53 and CHEK2 genes 664Breast cancer in men">Gene expression and cancer</a> 665<br/> 666 667<a href="A20/Using_genome_projects.html" title="Genome sequencing projects 668Vaccine production 669Sequencing methods 670The Sanger or chain termination procedure 671Automated sequencing">Using genome projects</a> 672<br/> 673<a href="A20/Recombinant_DNA_technology.html" title="Sources of DNA fragments 674DNA amplification 675Polymerase chain reaction (PCR) 676Use of enzymes to transfer sections of DNA 677Cell transformation 678Genetic engineering applied to blood clotting proteins 679Reverse transcriptase-polymerase chain reaction 680(RT-PCR) 681The first approved genetically modified food product ">Recombinant DNA technology</a> 682<br/> 683 684 685 686<a href="A20/identification_and_diagnosis_of_heritable_conditions.html" title="Heritable conditions 687Differences in DNA can be exploited for identification and diagnosis of heritable conditions 688DNA probes and hybridisation 689Fluorescence In Situ Hybridization (FISH) 690Screening patients for heritable conditions 691Carrier screening 692Dominant alleles 693Prenatal diagnostic testing 694Pre implantation screening 695Genetic counselling and personalised medicine 696Pharmacogenomics 697">Identification and diagnosis of heritable conditions</a> 698<br/> 699 700<a href="A20/Genetic_fingerprinting.html" title="Variable number tandem repeats (VNTRs) 701Minisatellites 702Microsatellites 703Short tandem repeats (STRs) 704Development of DNA fingerprinting 705Restriction Fragment Length Polymorphisms (RFLPs) 706DNA profiling 707Use of genetic fingerprinting and DNA profiling 708Determining genetic relationships 709Determining genetic variability within a population 710Application in forensic science 711Crime scene analysis 712Identification of body remains 713Exceptions to the rule 714 CAG repeats 715Huntington's disease 716polyQ diseases 717Genetic databases 718Familal searching">Genetic fingerprinting and DNA profiling</a> 719 720</span> 721 722<b>Others</b> 723 <a href="javascript:expandcontract('tables')"> 724<i title="These are now compatible with mobiles"><b>Some tabular data updated</b></i></a> 725<br/> 726<span id="tables" style="display:none"><a href="jsmol/jsVitamins_and_Minerals.html" title="I left off completing the last bit for some time">Vitamins and Minerals</a> ... <a href="jsmol/plant_minerals.html" title="Now adrift from the previous, and extended">Plant Minerals</a> ...<a href="g11/viral_diseases.html" title="Just a few - not exactly comprehensive 727- but incoming links data show this has gone viral!">Viral diseases</a> ... </span> 728 729 730 731 732 733 734<a href="javascript:expandcontract('water')"> 735<i title="All to show the special properties of the wet stuff"><b>More than just H<sub>2</sub>O - and in 3-D</b></i></a> 736<br/> 737<span id="water" style="display:none"><a href="jsmol/watersingle.html" title="See it in 3D">Water molecule</a> ... <a href="jsmol/waterHbonds.html" title="4 possible positions">H bonds in water</a> ... <a href="jsmol/watermoving.html" title="moving molecules animation">Liquid Water</a> ... <a href="jsmol/ice.html" title="See why it floats">Ice</a></span> 738 739 740and <a href="javascript:expandcontract('molecules')" title="Quite a few more to be added soon"> 741<i><b>Most recent 3-D Molecules</b></i></a> 742 743<span id="molecules" style="display:none"> 744 745<a href="jsmol/Carotene.html" title="A pigment with connections to Vitamin A"><b>Carotene</b></a><i> vs </i> <a href="jsmol/Keratin.html" title="A protein with lots of uses"><b>Keratin</b></a> - two quite different molecules! 746<br/> 747<a href="jsmol/Paxlovid.html"><b>Paxlovid</b></a> - Another new oral COVID-19 treatment awaiting approval 748<br/> 749 750<a href="jsmol/Molnupiravir.html"><b>Molnupiravir</b></a> <i>- a hopeful oral anti-COVID 19 drug</i> 751<br/> 752<a href="jsmol/remdesivir.html" title="an adenosine monophosphate analogue" target="_blank"> <b>Remdesivir</b> </a> <i>- an earlier possible anti-COVID 19 drug - for intravenous use</i> 753<br/> 754<a href="jsmol/halicin.html"><b>Halicin</b></a> - <i>the most recently announced potential new antibiotic</i> 755<br/> 756<a href="jsmol/lugdunin.html"><b>Lugdunin</b></a> - <i>the previous potential new antibiotic</i> 757<br/> 758<a href="jsmol/oxycodone.html" title="An (addictive) opioid, very similar to codeine"><b>Oxycodone (OxyContin)</b></a> <i>- A drug in the news</i> 759<br/> 760 761<a href="jsmol/salbutamol.html" title="Several antiasthma drugs 762Also used by cyclists"><b>Salbutamol+</b></a> <i> bronchodilator agents - some similar to adrenaline</i> 763<br/> 764 765<a href="jsmol/cardiolipin.html" title="Found in mitochondrial and some bacterial membranes"><b>Cardiolipin</b></a> <i>
765 phospholipid with 4 fatty acid tails</i> 766<br/> 767<a href="jsmol/NSAIDS.html" title="Ibuprofen, naproxen, diclofenac"> <b>NSAIDs</b> </a>Non Steroidal Anti Inflammatory Drugs 768<br/> 769</span> 770 771<br/> <b> Don't miss these: </b> 772 <br/> 773 <b><a href="howl/howl34.html" title="Not such a laugh - but they show the improvements which are needed both in comprehension and expression 774 And you can work back through them in chronological order">The most recent howlers</a></b> 775 776</center> 777 778 779 </div><!-- col span_1_of_3 --> 780 <div class="col span_1_of_3" style="background-color: #ffffcc; font-family: Sans-Serif; cursor: pointer;" title="Quite a popular feature of the BioTopics site: 781carbohydrates 782amino acids and proteins 783lipids 784nucleic acids 785vitamins 786antibiotics 787other compounds" onclick="window.location ='jsmol/jscontents.html'" title="This takes you to the Molecules Menu"> 788 789 <!-- RHS TOP BOX --> 790 791 <div align="center"> <br> 792 793 <b>3-D interactive structures of about 200 Biological molecules</b> 794 <br> 795 Being carbon-based, Biological molecules deserve better than a flat sheet of paper. 796 <br> 797 798 Check out the examples, and the interactive display format. 799 <br clear="all"> 800 </div> 801 <center> 802 <br> 803 <a href="jsmol/glucose.html" title="This takes you to the glucose molecule"><img alt="glucosefromjmol (1K)" src="glucosefromjmol.gif" height="97" width="90"/> 804<span title="The most basic carbohydrate" style="color:green">Glucose</span></a> 805 <br> 806 <!-- <h3><b>MOLECULES IN THE NEWS</b></h3> 807 808 <a href="jsmol/Molnupiravir.html"> 809 <img alt="molnupiravir_from_jsmol (28K)" src="molnupiravir_from_jsmol.png" width="90" title="A new oral treatment reducing the effects of COVID-19"/></a> 810 . . . 811 <a href="jsmol/Paxlovid.html"> 812 <img alt="paxlovidpic" src="paxlovidpic.png" width="90" title="Another new oral COVID-19 treatment 813 <!-- awaiting approval "/></a>--> 814<!-- height="265" width="373" --> 815<!-- <br> 816<a href="jsmol/Molnupiravir.html" title="A cytidine analogue" style="color:green">Molnupiravir</a> . . . <a href="jsmol/Paxlovid.html"><span title="A protease inhibitor" style="color:green">Paxlovid</span></a> --> 817 818 819 </center><br> 820<br> 821<!-- There was a problem with the display of .pdb files (proteins and other large molecules). This has now been fixed. 822I hope you are happy with all the molecules! --> 823 </div><!-- col span_1_of_3 --> 824</div> <!-- "section group" --> 825 826<!-- **SECOND LINE****************************************************************************** --> 827<div class="section group"> 828 829 <div class="col span_1_of_3" style="background-color: #FFCCFF; cursor: pointer;" title="Howlers are (laughable) mistakes made by my Biology students!" align="center" onclick="window.location ='howl/index.html'"> 830 831 832<div align="center"> 833<a href="howl/index.html" title="Click to go to the howlers menu page - Loads to choose from"><img src="rwolf.gif" title="Click here to see some more howlers" onmouseover="document.getElementById('wolfhowl').play()" align="right" border="0" height="50" width="50" alt="howlers"/><font face="Comic Sans MS" size="4">Howlers - 35 pages!</font></a><br/> 834 <audio id="wolfhowl"> 835<source src="howl/wolf5.mp3"/> 836</audio> 837 838
839<script language="JavaScript" type="text/javascript">document.write('<h4><font color="#FF00FF" title="I have collected loads of these howlers (29 pages) ..."> This one made me smile :</font></h4>');document.write('<font face="Comic Sans MS" color="#FFOOFF" title ="... but I had to choose a reasonably inoffensive one to put here at random (out of 24)...." >'+'"'+chosenhowl+'"'+'</font>');document.write('<h4><font color="#FF00FF"> Click here to see some others!</font></h4>');</script>
839 840 841 842</div><!-- center --> 843 844 </div><!-- col span_1_of_3" --> 845 846 847 <div class="col span_1_of_3"> 848 <!-- LOWER CENTRAL --> 849 850<center> 851 852<hr/> 853<h3>It is easy to get in touch using the contact options below</h3> 854<hr/> 855</center> 856</div> <!-- col span_1_of_3 --> 857 858 859 860 861 862 863 <div class="col span_1_of_3" style="background-color: #FFFFFF"> 864 <br> 865 <!-- Books --> 866 867<div align="center"> 868 869<a href="books/booklist.html" title="Books and other media 870"><b>Biological Books</b>- <i>recently restored</i></a> 871 872</div><!-- center --> 873 <ul> 874 875 <li><b><a href="books/AAS.html" title="Lots of options for the different boards 876 NOW BACK TO A SEPARATE LIST">LATEST AS and A level books</a> </b></li> 877 <li><a href="books/GCSEbooks.html" title="Now also a separate list"><b>GCSE books</b></a></li> 878 <li><b><a href="books/booklist.html#recommendations" title="From Biotutors">Recommendations for the 6th form</a></b></li> 879 <li><a href="books/booklist.html#interest" title="Richard Dawkins Matt Ridley Alice Roberts Richard Fortey David Attenborough 880Other stuff">General Interest (popular authors, other stuff)</a></li> 881 882 <li><a href="books/universaluk.html" title="This should track down and present a list of books - any subject any level">Universal book finder</a></li> 883 884 </ul> 885<hr> 886 <div align="center" title="Could be extended ... "><b>Biological supplies</b></div> 887 888 <div align="left"> 889 <ul> 890 891 <li> 892 <a href="anatomical.html" title="Some useful props - available online 893 Amazon.com seem to have improved the delivery of these links 894 Please let me know if you experience any difficulty">Anatomical models</a> 895 </li> 896 </ul> 897 </div> <!-- left --> 898 899 900 </div><!-- col span_1_of_3 --> 901</div><!-- section group --> 902 903<center> 904Advertisers on this site use cookies for analytics, advertising and to personalise adverts served. 905<br/> 906By continuing to use this site, you agree to their use of cookies. 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Line numbers count LF bytes from the start of the resource, as the search results do. Vendor segments are library code the classifier recognised; they are stored but not indexed. Bytes are shown as Latin1 characters, one per byte.