Basic Concepts of Biology PDF

KEY CONCEPTS IN BIOLOGY BIOLOGY: The Study of Life derived from the Greek words “bios” (life) and “logos” (study) the study of living organisms divided into many specialized fields that cover their morphology (form & structure), physiology (functions, activities, processes and...

KEY CONCEPTS IN BIOLOGY BIOLOGY: The Study of Life derived from the Greek words “bios” (life) and “logos” (study) the study of living organisms divided into many specialized fields that cover their morphology (form & structure), physiology (functions, activities, processes and phenomena) , anatomy (structural organization), behavior, origin, and distribution of organisms MAJOR BRANCHES OF BIOLOGY Botany – is the scientific study of plants. It includes the study of their structure, how they grow, how they can be effectively classified, the things that impact their development, etc. Theophrastus is known as the father of Botany. Zoology (also known as animal science) is the branch of biology devoted to the study of animal life. It covers areas ranging from the structure of organisms to the subcellular unit of life. Aristotle is known as the father of Zoology. MAJOR BRANCHES OF BIOLOGY Microbiology is the study of microscopic organisms, such as bacteria, viruses, archaea, fungi and protozoa. This discipline includes fundamental research on the biochemistry, physiology, cell biology, ecology, evolution and clinical aspects of microorganisms, including the host response to these agents. Leeuwenhoek is known as the father of Microbiology. Viruses are tinier than bacteria. In fact, the largest virus is smaller than the smallest bacterium. All viruses have a protein coat and a core of genetic material, either RNA or DNA. Unlike bacteria, viruses can't survive without a host. They can only reproduce by attaching themselves to cells.  A fungus (plural: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. Protozoa (also protozoan, plural protozoans) is an informal term for a group of single-celled eukaryotes, either free-living or parasitic, which feed on organic matter such as other microorganisms or organic tissues and debris. OTHER BRANCHES/ FIELDS OF BIOLOGY THEMES OF BIOLOGY Cell structure and function Stability and homeostasis Reproduction and inheritance Evolution Interdependence of organisms Matter, energy, and organization 7  CHARACTERISTICS OF LIFE All living things are organisms that share common traits 1. Organized cell structure * Unicellular or multicellular * Cells are organized into tissue, tissue organized into organs, organs organized into an organ system, and an organ system organized into a organism CHARACTERISTICS OF LIFE 2. Reproduction Includes mechanism for heredity: DNA and genes All organisms produce new organisms like themselves (REPRODUCE) Organisms transmit hereditary information to their offspring (INHERITANCE) SEXUAL REPRODUCTION Hereditary information from two different organisms of the same species are combined Egg and sperm 🡪 zygote (fertilized egg) Zygote contains hereditary information from both parents ASEXUAL REPRODUCTION -a type of reproduction which does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from a single cell or from a multicellular organism inherit the genes of that parent.  CHARACTERISTICS OF LIFE 3. Metabolism: chemical changes in living cells by which energy is provided for vital processes and activities and new material is assimilated There are 2 basic types of metabolism Anabolism: store energy in molecules Catabolism: release energy from molecules 4. Homeostasis: maintain stable internal conditions in spite of changes in external environments (Temperature, water content, chemical content must be maintained NOTE: More information about homeostasis can be found at the latter part of this presentation. 5. Evolution as a species Change in inherited traits of a ▶ Populationsof organisms species over time change (evolve) over Species: group of genetically generations (time) similar organisms. that can ▶ Explains how many produce fertile offspring different kinds of organisms came into existence SPECIES ▶ Explainshow modern organisms are related to past organisms  Survival of organisms with Natural selection: The Driving favorable traits cause a gradual Force of Evolution change in populations over many generations - environment selects individuals with 🡪 Also called “Survival of the sets of traits that increase chances of Fittest” survival and reproduction- adaptation 6. Respond to stimuli Stimuli may be: touch, light, temperature, sound, pressure, bacteria, viruses, behavior, food, etc. Examples: “Fight or flight”, “fever”, “vomiting”, 7. Interdependence Organisms are dependent on one another and their environment as a result of long history of evolutionary adjustments Interaction of organisms with one another and with their environment ECOLOGY Insects and flowers DEPEND on each other for food & pollination COEVOLUTION 8. Common set of macromolecules Proteins— metabolism/homeostasis, movement Carbohydrates—structure, energy storage Lipids—energy storage, transport, cellular integrity Nucleic acids—reproduction, heredity, evolution Classification The old classification system: King Phillip Came Over For Great Spaghetti Domain has been added above Kingdom which is the most inclusive taxon divided into 3 groups. Before domains were added, there was one kingdom-Monera. Archae Prokaryotic (non-nucleated, single-celled) A recent discovery Bacteria most familiar of prokaryotes found in all common environments Eukarya Nucleated, eukaryotic cells 4 kingdoms: Animalia, Plantae, Fungi, Protista The new classification system: 🡪 All organisms need substances such as nutrients, water, and gases from the environment 🡪 The stability of the environment depends on the healthy functioning of organisms in that environment Cells in Focus  Cell is the basic structural and functional unit of living organisms. It is the smallest unit of life, hence, it is often called the “building block of life” Cells provide structure for the body, take in nutrients from food and carry out important functions. Main Functions of A Cell 1.provide structure and support 2.facilitate growth through mitosis 3.allow passive and active transport 4.produce energy 5.create metabolic reactions 6.aid in reproduction.  CHARACTERISTICS OF CELLS ◼All cells are composed primarily of carbon, hydrogen, nitrogen, and oxygen. 59% Hydrogen (H); 24% Oxygen (O); 11% Carbon (C) 4% Nitrogen (N); 2% Others - Phosphorus (P), Sulfur (S), etc. ◼All cells have the same basic parts and some common functions. ◼A generalized human cell contains the plasma membrane, the cytoplasm, and the nucleus. Source: https://www.byjus.com/biology/cells/  DIVERSITY OF CELLS Types of Cell in the Body Source: https://youtu.be/A4jEum_AcH8 Common Parts of A Cell Although cells are diverse, all cells have certain parts in common. Plasma membrane a thin coat of lipids that surrounds a cell. It forms the physical boundary between the cell and its environment, so you can think of it as the “skin” of the cell Cytoplasm made up of a watery substance called cytosol, and contains other cell structures such as ribosomes. Ribosomes structures in the cytoplasm where proteins are made. DNA DNA is a nucleic acid found in cells. It contains the genetic instructions  PLASMA MEMBRANE ⮚ (Aka)Cell membrane Composition: Bilayer of lipids and proteins. ⮚ Job: Allow materials to enter and exit the cell. ⮚ Semi-Permeable: only specific materials may enter and exit through pores and protein channels. Source: https://www.byjus.com/biology/cells/  CELL WALL ◼ The cell wall is the most prominent part of the plant’s cell structure. It is made up of cellulose, hemicellulose and pectin. ◼ It is present exclusively in plant cells. ◼ It is a rigid and stiff structure surrounding the cell membrane. ◼ It provides shape and support to the cells and protects them from mechanical shocks and injuries. Source: https://www.byjus.com/biology/cells/  CYTOPLASM ◼ The cytoplasm is a thick, clear, jelly-like substance present inside the cell membrane. ◼ Most of the chemical reactions within a cell take place in this cytoplasm. ◼ Most organelles float within; - Nucleus - Ribosomes - Vacuoles - Mitochondria - Chloroplasts - Endoplasmic reticulum - Golgi Body - Lysosome Source: https://www.byjus.com/biology/cells/  NUCLEUS ◼Job: Controls cell activity ◼Inside the Nucleus: - long strands of DNA - holds information to make proteins. Source: https://youtu.be/RKmaq7jPnYM DNA (Deoxyribonucleic Acid) Genetic Information in all cells DNA contains instructions for traits GENES Make the structures and complex chemicals necessary for life PROTEINS DNA in every body cell (SOMATIC CELLS) is exactly alike  CELL ORGANELLES ◼Cells are composed of various cell organelles that perform certain specific functions to carry out life process. Source: https://www.byjus.com/biology/cells/  CELL ORGANELLES AND ITS FUNCTION ⮚ Nucleolus – The nucleus job is to makes ribosomes. ⮚ Endoplasmic reticulum – It is involved in the transportation of materials within the cell. 2 types: Rough ER - Receives ribosome from the nucleus and transport it making protein. Smooth ER - makes fats and break down toxins. (no ribosome) Source: https://youtu.be/RKmaq7jPnYM  CELL ORGANELLES AND ITS FUNCTION ⮚ Ribosomes - It is created by nucleolus. - Transported by rough ER. - Its job is to make proteins ⮚ Golgi Bodies - It is involved in the transportation of materials within the cell. - Its job is to modify, sorts and packages protein. Source: https://youtu.be/RKmaq7jPnYM  PROTEIN SHIPMENT 1. Nucleolus makes ribosomes. 2. Ribosome travels through rough ER making proteins. 3. Golgi Body sorts and packages the protein. 4. Vesicle releases the protein from the cell. Source: https://youtu.be/RKmaq7jPnYM  CELL ORGANELLES AND ITS FUNCTION ⮚Mitochondria – AKA: Powerhouse of the cell. - It protects the ATP – the cells energy currency. ⮚Lysosomes - AKA: Suicidal bag of the cell - It contain digestive enzyme. – It protects the cell by engulfing the foreign bodies entering the cell and helps in cell renewal. - Jobs: Break down food, kill pathogens, and destroy dying cell. Source: https://youtu.be/RKmaq7jPnYM  CELL ORGANELLES AND ITS FUNCTION ◼ Chloroplast – It is the primary organelles for photosynthesis. ◼ Vacuoles - It stores food, water, and other waste materials in the cell. Source: https://www.byjus.com/biology/cells/  Types of Cells There are two cell types: prokaryotes and eukaryotes Prokaryotic cells are usually single-celled and smaller than eukaryotic cells Eukaryotic cells are usually found in multicellular organisms, (but there are also some single- celled eukaryotes) Diagram of a Prokaryotic Cell Prokaryotes are the smallest types of cells, averaging 2-5μm (micrometer) in diameter. Despite their small size, inside each cell there is chemical and biochemical machinery necessary for growth, reproduction, and the acquisition and utilization of energy. Common Features of Prokaryotic Cell microscopic organisms have neither a membrane- bound nucleus nor membrane- * cell wall bound organelles * plasma membrane have ribosomes surrounded by a genetic material membrane but do have a specialized function, and could therefore be Reproduction in prokaryotic cells considered organelles. is called binary fission all metabolic functions carried out by a prokaryote take place in the plasma membrane or the cytosol.  Diagram of a Eukaryotic Cell A eukaryote is an organism whose cells are organized into complex structures by internal membranes and a cytoskeleton  Eukaryotic Cell most characteristic membrane-bound structure is the nucleus. The nucleus is the membrane-enclosed organelle that contains DNA. Eukaryotic DNA is organized in one or more linear molecules, called chromosomes. Some eukaryotes are single-celled, but many are multicellular. Eukaryotes include all protists, fungi plants and animals. contain membrane-bound organelles. Each organelle in a eukaryote has a distinct function. Because of their complex level of organization, eukaryotic cells can carry out many more functions than prokaryotic cells. The Plant Cell Plant cells are the basic unit of life in organisms of the kingdom Plantae. They are eukaryotic cells, which have a true nucleus and structures called organelles that carry out different functions. Plant cells have special organelles called chloroplasts, which create sugars via photosynthesis. The Animal Cell Animal cells are the basic unit of life in organisms of the kingdom Animalia. They are eukaryotic cells, meaning that they have a true nucleus and specialized structures called organelles that carry out different functions. Plant Cells vs Animal Cells GROWTH ◼Growth occurs as the result of cell division and cell enlargement ◼Cell division is the formation of two cells from a preexisting cell ◼New cells enlarge as they mature ◼When a cell grows to a size where its surface area isn’t big enough for its volume, the cell divides COPYRIGHT CMASSENGALE 53  CELL DIVISION ◼ MITOSIS CELL DIVISION ◼ Mitosis is how somatic—or non- ▶ MEIOSIS CELL DIVISION reproductive cells—divide. Somatic cells make up most of your body's ▶ Meiosis is cell division that creates sex tissues and organs, including skin, cells, like female egg cells or male sperm muscles, lungs, gut, and hair cells. cells. ? In meiosis, each new cell contains a Reproductive cells (like eggs) are unique set of genetic information. After not somatic cells. meiosis, the sperm and egg cells can join to In mitosis, the daughter cells each have create a new organism. the same chromosomes and DNA as the parent cell. COPYRIGHT CMASSENGALE  DEVELOPMENT ◼The process by which an adult organism arise is called development ◼Repeated cell divisions and cell differentiation COPYRIGHT CMASSENGALE 55 ORGANIZATION OF LIVING THINGS 1. Organization of Cell Cells are arranged differently in unicellular, multicellular and colonial organism. Unicellular organisms such as bacteria are made of one independent cell. The cell can carry out all the necessary functions in the organism. Multicellular organism such as animals and plants consist of specialized cells that work together to perform different tasks. This cells cannot survived on their own if separated. Colonial organism refer to a colony of single-celled organism living together. The Colonial Flagellate Hypothesis proposes that the cells unicellular organism aggregated to form a colony. The cells in the colony could survive on their own if separated. These were the first multicellular organisms.  ◼Cells are grouped together to form tissues, layers of different types of tissue make up organ. youtube.com ◼Organ with similar functions are grouped into organ system which make up an organism. ◼Organ System help deliver nutrients and remove wastes from the organism. References: Matrix, ”2: Organization of Living Things,” Matrix Education. http://www.mtrix.edu.au/beginners-guide-to-year-11- biology/organisation-of- living-things/. Accessed 26 September 2020. CNX, “Introduction Biology,” OpenStax. https://cnx.org/contents/[email protected]:rZudN6XP@2/Introd uction. Accessed 26 September 2020. Anderson, Hayley, “Unicellular Organism,” MiscroscopeMaster. https://www.microscopemaster.com/unicellular-organisms.html. Accessed 27 September 2020. tanley, Morgan, “Autotrophs,” National Geographic. https://www.nationalgeographic.org/encyclopedia/autotroph/#:~ :text=An%20aut otroph%20is%20an%20organism,they%20are%20sometimes% 20called%20pr oducers. Accessed 27 September 2020. https://www.thoughtco.com/types-of-cells-in-the-body-373388 HOMEOSTASIS Homeostasis is the process by which organism maintain a relatively constant or stable internal environment for body cells. ✔the word homeostasis came from the ancient greek Homeo - means the same stasis - to stay TWO STAGE OF HOMEOSTASIS 1. Detecting changes from stable state. 2. Counteracting changes from the stable state. MECHANISM homeostasis is maintained by feedback system feedback is a way of establishing body system such as nervous and endocrine systems. Homeostasis is achieved through positive and negative feedback mechanism. NEGATIVE FEEDBACK Includes most homeostatic control mechanism shuts off the original stimulus or reduces its intensity works like a household thermostat. includes control of blood pressure and temperature regulation. POSITIVE FEEDBACK Increases the original to push the variable further; intensifies the response until an endpoint is reached (e.g. blood clothing, contractions during child birth, breastfeeding) Note: Homeostasis mechanism are design to re- establish homeostasis when there is imbalance. POSITIVE FEEDBACK CAN BE HARMFUL & LIFE-THREATENING Example: A fever triggered by infection is beneficial up to a point, but if the body temperature rises much above 42°C, it may create a dangerous positive feedback loop. This high temperature raises the metabolic rate, which makes the body produce heat faster than it can get rid of it. Thus, temperature rises still further, increasing the metabolic rate and heat production still more. This "vicious circle" becomes fatal at approximately 45°C. WHY IS HOMEOSTASIS IMPORTANT? Most of the cells are made up of water. Water expands when frozen and the cell membranes will rupture...cells die. When enzymes are slow functioning at low temperature, metabolism then slows at >45°C enzymes denature., metabolism slows or irreversibly stop EXAMPLES OF HOMEOSTASIS REACTION. when you go for a run outside your body can build up sweat. this is your body reaction to cool you down. If you touch a hot pan, your body will jerk back in reflex. This is your nervous system protecting your body from harm. EXAMPLE OF HOMEOSTATIC MAINTENANCE Inside the body there is a constant maintenance of: blood pH level (~7.4 pH) blood pressure water levels salt balance wastes oxygen an carbon dioxide concentration blood glucose levels body temperature nutrient concentration  MAINTAINING THE INTERNAL ENVIRONMENT both plants and animals act to maintain a balance in their internal environments despite external condition. an example of homeostasis that occur in both plants and animals include temperature regulation.  Our body will function optimally at TEMPERATURE 37°C (it can fluctuate between 36°C and 37.8°C ) If your body goes outside the " normal " internal body Temperature temperature range, your body may maintenance not cope and therefore this can be risky or even fatal (above 42°C)  Fever can be extremely serious if Temperature your body temperature raises or maintenance lowers to much outside this range. - this is due to enzymes and their ability to only work in narrow temperature range. Outside this temperature range, enzymes denature and they will not function. Nutrient maintenance NUTRIENT CONCENTRATION A lack of nutrient may lead to disease such as lack of vitamin C may lead to a disease called scurvy. some symptoms of scurvy are bleeding of gums, loosened teeth, lack of appetite and diarrhea. Oxygen and Carbon dioxide level Because Carbon dioxide readily dissolves in water, it lowers the pH of the blood to become acidic. Carbon dioxide needs to be removed as quickly as possible, because this lowering of pH affects the homeostasis and can denature enzyme. Oxygen and Carbon dioxide level By removing excess carbon dioxide, it prevents a build - up of carbon acid When there’s a build up of carbonic acid, it increases breathing rate and depth; this will balance out the pH of the blood. Carbonic acid forms when carbon dioxide dissolve in water. Maintaining chemical substances within the body The body is controlled by chemical substances available to cells. These chemical substances are transported through organism (by blood vessels in mammals and vascular tissues in plants. Maintaining the internal environment Examples: -the control of water and salt balance (osmoregulation) -the control of pH and waste products (brought about mainly by the kidney in mammalian bodies.) More Homeostatic process - External influences Our bodies can react in different ways depending on the changes and fluctuation in external environment. Example: changes in exercise -If you exercise more, your body will gain muscle. Changes in sleep patterns If you sleep less one night, the next day your body will feel more tired and you may sleep longer the following night Changes in diet If you eat more acidic foods your body will alter the pH to bring it back to normal level. Changes in Temperature Your body responds to a decrease in temperature by contracting blood vessels or shivering (contracting muscle) or raise hair in the surface of the skin to trap heat. You may also desire to put extra clothes or seek shelter. Changes in light and seasonal changes With changes in altitude, your breathing rate might increase as the air is thinner at higher altitudes. Homeostatic responses Animals need not only to detect but to respond to the internal and external environment. this is called homeostatic responses. Effectors are the body's responses mechanism, example includes muscle and glands. some homeostatic responses occurs quickly, and we call these reflexes. Homeostasis in different organism Homeostasis and receptor sensitivity differs in different organism Different animals have different levels of visual abilities depending on animals’ environment and requirement for survival. Homeostasis in different organism Eagles have well developed visual senses to detect small moving objects - to be able to hunt for prey while at a height whereas other animals such as wombat does not have the same visual acuity. Homeostasis in different organism dogs have a stronger ability to detect chemical sense via their sense of smell than humans. snakes can detect and use infrared, heat and radiation. platypuses can detect weak electric field generated by their prey. TYPES OF HOMEOSTATIC REGULATION IN THE BODY Generally, there are three types of homeostatic regulations in the body 1. Thermoregulation Thermoregulation is the process occurring inside the body that is responsible for maintaining the core temperature of the body. Thermoregulation works by the negative feedback loop where once the body temperature is either increased or decreased beyond its normal temperature, it is brought back to normal.  Different homeostatic processes like sweating, dilation of blood vessels counteract the increased body temperature, whereas processes like contraction of blood vessels, and breakdown of adipose tissue to produce heat prevent the decreased body temperature. The process of thermoregulation is maintained by organs like skin and adipose tissue of the integumentary system and the hypothalamus of the brain. 2. Osmoregulation Osmoregulation is the process of maintaining a constant osmotic pressure inside the body by balancing the concentration of fluids and salts. During this process, excess water or ions or other molecules like urea are removed from the body to maintain the osmotic balance.  One classic example of this process is the removal of excess water and ions out of the blood in the form of urine to maintain the osmotic pressure of the blood. The rennin-angiotensin system and other hormones like antidiuretic hormones act as a messenger for the electrolytic regulation system of the body. 3. Chemical regulation Chemical regulation is the process of balancing the concentration of chemicals like glucose and carbon dioxide in the body by producing hormones. During this process, the concentration of hormones like insulin increases when the blood sugar level increases in order to bring the level back to normal.  A similar process is observed in the respiratory system, where the rate of breathing increases as the concentration of carbon dioxide increases.  Differences Between Breathing and Respiration  Differences Between Breathing and Respiration REFERENCES: RESOURCES https://www.google.com/url?sa=t&source=web&rct=j&url=https://m.youtube.com/watch%3Fv%3DxfeMq 4O9jV0&ved=2ahUKEwjuh7TT6OfrAhUGrJQKHWtIBdcQt9IBMAV6BAgSEAg&usg=AOvVaw0zDzM8Tg2KaYz1wit 8sApo https://www.google.com/url?sa=t&source=web&rct=j&url=https://microbenotes.com/homeostasis/&ved =2ahUKEwjezvC28efrAhWSBKYKHQErBFsQFjAFegQIDRAJ&usg=AOvVaw2_OMgrQOtzUmYrPNXO38CY&cshid=1 600060560140 https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.slideshare.net/mobile/nileshkat e79/homeostasis- 45948009&ved=2ahUKEwio2uvVuujrAhUCZt4KHYeeCXwQFjAJegQIAxAB&usg=AOvVaw3BaE0Rb1v- 0tNUMkJIgW9l&cshid=1600080194870 https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.slideshare.net/mobile/09781361 02/homeostasis- 51538501&ved=2ahUKEwio2uvVuujrAhUCZt4KHYeeCXwQFjAAegQIAhAB&usg=AOvVaw3y1uDZElNAxFdOr2Dp Kcrp&cshid=1600080194870 https://byjus.com/biology/difference-between-breathing-and-respiration/