FM Lecture 1 Cytogenetics (T209) 2024-2025 Ain Shams University PDF

Ain Shams University Faculty of Agriculture Genetics Department English Program of Biotechnology Second Level Lecture 1 2024/2025  ‫(‬ ‫))‬ ‫(‬ ‫تنبيه هام لجميع...

Ain Shams University Faculty of Agriculture Genetics Department English Program of Biotechnology Second Level Lecture 1 2024/2025  ‫(‬ ‫))‬ ‫(‬ ‫تنبيه هام لجميع طلبة‬ ‫أبنائي الطالبات والطلبة‬ ‫كل عام دراسى جديد وأنتم بخير‬ ‫أنبه عليكم جميعا أن محتوى شرائح الباوربوينت للمحاضرات وحدها فقط ال يكفى كمصدر‬ ‫للمذاكرة‪.‬ولكن البد من المذاكرة لموضوع كل محاضرة من عرض الباوربوينت إلى جانب‬ ‫موضوع المحاضرة (الفصل ‪ )Chapter‬بالكتاب اإللكترونى‪.‬ووقت المحاضرة ال يكفى‬ ‫بعرض معظم النقاط العلمية حيث نهتم بشرح النقاط التى تحتاج لشرح وتفصيل‪.‬وبالتالي‬ ‫البد من الدمج والتكامل بين محتوى الباوربوينت بالمحاضرة والمحتوى النظرى بالكتاب‬ ‫اإللكترونى لكل موضوع‪.‬‬ ‫كما يوجد بنهاية الكتاب اإللكترونى نماذج لألسئلة على كل فصل (محاضرة) من فصول‬ ‫الكتاب‪.‬للتدريب على نوعية األسئلة وموضوعاتها وقياس مدى فهم وإستيعاب الطالب‬ ‫لموضوع المحاضرة‪.‬‬ ‫مع أطيب تمنياتى لكم جميعا بالنجاح والتوفيق‪.‬‬  ‫التعليم هو ما يفعله الناس لك‬ (Education is what people do to you) ‫التعلم هو ما تفعله لنفسك‬ (Learning is what you do for yourself) There is a fundamental difference ‫المصادر‬ ‫التعليم‬ Resources Education ‫التعلم‬ Learning ‫األفراد أو األشخاص‬ Individuals *Research in Learning Technology, Vol 20, 2012. tinyurl.com/nb5yc42 scientific study of cells study of heredity Cyto-genetics ‫الوراثة الخلوية‬ Cytogenetics “T209” The Cell  Glossary vs Dictionary Glossary (‫)قائمة المصطلحات‬ A glossary, also known as a vocabulary or terms, is an alphabetical list of terms in a particular domain of knowledge with the definitions for those terms. Dictionary (‫)قاموس‬ A dictionary, sometimes known as a wordbook, is a collection of words in one or more specific languages, often arranged alphabetically, which may include information on definitions, usage, etymologies, pronunciations, translation, etc. or a book of words in one language with their equivalents in another, sometimes known as a lexicon.  The CELL A cell is the smallest unit that is capable of performing life functions  Matthias Schleiden Theodor Schwann Rudolf Virchow  The cell theory 1) All organisms are composed of one or more cells 2) The cell is the simplest structure that can perform all activities required for life 3) All cells come from other pre-existing cells by cell division ‫عزيزتى الطالبة حاول أن تصيغ هذه الجمل مرة أخرى لتحمل‬/‫عزيزى الطالب‬ :‫نفس المفهوم والمعنى العلمى كما يلى‬ The cell theory 1. All organisms are made of one or more cells 2. The cell is the basic unit of all living things 3. All cells come from existing cells A Timeline 1665 – Hooke described ‘cells’ in cork. He remarked that it looked strangely similar to cellula or small rooms which monks inhabited, thus deriving the name. 1674 – Leeuwenhoek discovered protozoa. He described the algae Spirogyra. He probably also saw bacteria. 1838 – Schleiden and Schwann proposed cell theory. 1858 – Rudolf Virchow (physician, pathologist and anthropologist) expounds his famous conclusion: that is cells develop only from existing cells 1857 – Kolliker described mitochondria. 1879 – Flemming described chromosome behavior during mitosis. 1883 – Germ cells are haploid, chromosome theory of heredity. 1898 – Golgi described the golgi apparatus. 1938 – Behrens used differential centrifugation to separate nuclei from cytoplasm. CONCLUSION: The “Cell Theory” was an amazing discovery when it comes to cytology Cytology is the study of cells The structural and functional units of all living organisms are cells. Cells are the building blocks of life All living organisms are made up of cells In the human body there are about 100 trillion (1012) to (1014) cells The cell contains cellular organelles that control the activity of the cell  ‫التعلم الذاتى‬ SELF LEARNING WHY ARE CELLS SO SMALL ? Surface-area-to-volume relationships ▪ Organisms can be classified as unicellular and mutlicellular organisms. ▪ Unicellular organisms are made up of a single cell like most bacteria, while the multicellular organisms include plants and animals. ▪ The number of cells varies between species. ▪ The size of most plant cells and animal cells is between 1 to 100 micrometers; hence they are visible under microscope. Different Types of animal cells Different Types of plant cells Review Facts About Living Things  What Are the Main Characteristics of organisms? 1. Made of CELLS 2. Require ENERGY (food) 3. REPRODUCE (species) 4. Maintain HOMEOSTASIS* 5. ORGANIZED (The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere) 6. RESPOND to environment 7. GROW and DEVELOP 8. EXCHANGE materials with surroundings (water, wastes, gases) ‫*حيث ينظم جسم الكائن بيئته الداخلية بغرض الحفاظ على استقرارها وثباتها أمام تغيرات قد تكون‬ )‫داخلية أو خارجية (مثل اإلجهادات البيئية كإرتفاع درجة الحرارة‬  5 6 4 3 7 2 10 1 8 3 2 9 1 Outlines the visual range of the eye, light microscope and electron microscope  Microscopes reveal the world of the cell ▪ The early microscopes provided data to establish the “Cell Theory” – That is, all living things are composed of cells and that all cells come from other cells – A variety of microscopes have been developed for a clearer view of cells and cellular structure – The most frequently used microscope is the Light Microscope (LM)—like the one used in biology laboratories – Light passes through a specimen then through glass lenses into the viewer’s eye – Specimens can be magnified up to 1,000 times the actual size of the specimen  ‫التعلم الذاتى‬ SELF LEARNING Objectives lens Dual lens system Ocular or Eye lens lens system Objectives lenses ‫التعلم الذاتى‬ SELF LEARNING How Many Lenses Are in a Compound Microscope?  Eye lenses ocular, or eyepiece lens Ocular or Eyepieces  Ocular or Light microscope (LM) ‫المجهر الضوئي‬ Enlarges image Eyepiece formed by objective ‫القطعة العينية‬ Lens ‫لتكبير الصورة المكونة‬ Ocular ‫بالعدسات الشيئية‬ Lens ‫العدسة العينية‬ Magnifies specimen, Objective lens forming primary ‫العدسة الشيئية‬ Image ‫لتكبير العينة وتكوين الصورة األولية‬ Specimen ‫العينة‬ Condenser Focuses light Lens through specimen ‫العدسة المكثفة‬ ‫لتركيز الضوء خالل العينة‬ Light source ‫مصدر الضوء‬ Microscopes have limitations – Both the human eye and the microscope have limits of resolution-the ability to distinguish between small structures ‫– كال العين البشرية والمجهر لهما قدرة محدودة على التمييز بين التراكيب الصغيرة‬ – Therefore, the light microscope cannot provide the details of a small cell’s structure ‫– لذلك اليستطيع المجهر الضوئي توضيح تفاصيل التراكيب الخلوية الصغيرة‬ – Biologists often use a very powerful microscope called the electron microscope (EM) to view the ultrastructure of cells ‫– يستخدم علماء األحياء مجهر قوي جدا ً يعرف بالمجهر اإللكتروني لتوضيح التركيب الدقيق للخاليا‬ – It can resolve biological structures as small as 2 nanometers and can magnify up to 100,000 times ‫ ضعف‬100.000 ‫ ويملك قدرة تكبير تصل لـ‬، ‫ نانومتر‬2 ‫– يمكنه أن يوضح تراكيب حيوية بحجم‬ – Instead of light, the EM uses a beam of electrons ‫– يستخدم المجهر اإللكتروني حزمة من االليكترونات عوضا ً عن الضوء‬  Magnification !! ‫تكبير أو تضخيم‬ Virtual images Total magnification = Objective magnification X ocular magnification Magnification The ability of the lens to enlarge the visual image of the object (Power of the lens) )‫ قدرة العدسة على تكبير الصورة المرئية للكائن (قوة العدسة‬ Magnifying power calculation: Divide the total magnification of the object by the power of the objective lens Ex. Total magnification (200x) = magnifying power (5x) Objective lens power (40x) Resolving power (‫)قدرة التمييز‬ The ability of the microscope to distinguish fine detail - ability to distinguish between 2 objects that are so close together they appear as one Resolving power is the capacity of an instrument to resolve two points which are close together.  Magnification vs. Resolution Magnification is how Resolution is the much bigger a sample ability to distinguish appears to be under the between two points on microscope than it is in an image - the amount real life. of detail. Total Magnification = e.g. if two objects are less objective magnification x than 200nm apart they are eyepiece magnification seen as one object. Increasing the magnification does not increase the resolution of the image!!  Magnification vs. Resolution 1 2 4 3 Pseudo magnification !!? Electron microscopes ❑ Generates a beam of electrons (0.004nm wavelength) ❑ Distinguishes between objects 0.2nm apart. How is this different from a light microscope? Uses magnets instead of lenses to focus the beam onto the specimen Image is projected onto photographic paper to make a grey scale image (Black & white Electronmicrograph) Blood clot: platelets spin out a mesh of fibrin. Taken from a scanning electron microscope  Transmission Scanning Electron Electron Microscope Microscope (TEM) (SEM) Electron beam passes Electrons don't pass through through a thin sample the specimen. Electrons pass through the They bounce off the denser parts less easily – specimen. contrast Image is 3D view Image is 2D view Magnification is 100,000 x Magnification is 500,000 x http://www.youtube.com/watch?v=lrXMIghANbg What can we see with a microscope?  ‫التعلم الذاتى‬ SELF LEARNING LIGHT, SEM or TEM?  Light micrograph of a protist, Paramecium ‫صورة بالمجهر الضوئي للكائن األولي البراميسيوم‬ Transmission electron micrograph of Paramecium ‫صورة بالمجهر اإللكتروني النافذ للبراميسيوم‬ Scanning electron micrograph of Paramecium ‫صورة بالمجهر اإللكتروني الماسح للبراميسيوم‬ Micrograph produced by differential interference-contrast microscopy of Paramecium. ‫صورة للبراميسيوم بواسطة مجهر التباين التداخلي التفريقي‬  ‫التعلم الذاتى‬ SELF LEARNING DIFFERENT TYPES OF LIGHT MICROSCOPY: 1. DARK FIELD MICROSCOPY 2. FLUORESCENCE MICROSCOPY 3. PHASE CONTRAST MICROSCOPY 4. POLARIZED MICROSCOPY 5. CONFOCAL MICROSCOPY DIFFERENT TYPES OF ELECTRON MICROSCOPY: 1. REFLECTION ELECTRON MICROSCOPE (REM) 2. SCANNING TRANSMISSION ELECTRON MICROSCOPE (STEM) 3. SCANNING TUNNELING MICROSCOPY (STM)  ‫مكافئات القياس الطولية‬ ‫‪MEASUREMENT EQUIVALENTS‬‬ ‫‪ 1‬متر (م) = ‪ 0 10‬م = ‪ 39.37‬إنش‬ ‫‪ 1‬مليمتر (ملم) = ‪ 3- 10‬م (‪ 1/1000‬م) = ‪ 0.04‬إنش‬ ‫‪ 1‬ميكرومتر = ‪ 3- 10‬ملم = ‪ 6-10‬م (‪ 1/1000,000‬م)‬ ‫‪ 1‬نانومتر = ‪ 3- 10‬ميكرومتر = ‪ 9- 10‬م (‪)1/1000,000,000‬‬ ‫‪1‬م = ‪ 103‬ملم = ‪ 106‬ميكرومتر = ‪ 109‬نانومتر‬