Biology Lessons 1-8 PDF

LESSON 1 - CELL THEORY ====================== Characteristics for Living Things --------------------------------- - - - - - - - - - - Cell Theory ----------- (Original) - - - (Modern) - - - Spontaneous Generation (Abiogenesis) ------------------------------...

LESSON 1 - CELL THEORY ====================== Characteristics for Living Things --------------------------------- - - - - - - - - - - Cell Theory ----------- (Original) - - - (Modern) - - - Spontaneous Generation (Abiogenesis) ------------------------------------ The spontaneous generation was when scientists and people believed that living things can arise from nonliving things. REDI rotted meat in three different jars, one with an unclosed lid, one with cork, and one with gauze covered. He proved that rotten meat will not make maggots, but rather, maggots lay their larvae eggs onto the meat. PASTEUR settled the argument of the spontaneous generation by boiling broth in a gooseneck flask. He proved that the dust and microbes will get trapped in the gooseneck and when he broke the gooseneck, microbes started growing in the broth in a couple of days. HOOKE used a microscope to look at cork cells and realized that the little boxes reminded him of cells in a jail, hence why we call the basic unit of life, 'cells'. Classification of Cells ----------------------- PROKARYOTIC cells are unicellular, don\'t have a nucleus, don\'t have a cell membrane, 10-1000x smaller than eukaryotic cells, organelles aren't membrane-bound, DNA floats around in the cell. EUKARYOTIC cells are multicellular, have membrane-bound organelles, 10-1000x larger than prokaryotic cells, and have a nucleus which contains the DNA, more complex. LESSON 3 - INFECTIOUS DISEASES ============================== DISEASES are abnormal conditions that are identified by symptoms. SYMPTOMS are physical and chemical changes that are seen when you have a disease. Some factors that cause disease are injuries, genes, stress, unhealthy lifestyle, diet, and pathogens. Pathogens --------- PATHOGENS are microbes that cause diseases by infecting a host. INFECTIONS are how pathogens present themselves in a host. A few types of pathogens include parasites, bacteria, viruses, fungi, and protozoa. Zoonotic Diseases ----------------- ZOONOTIC DISEASES are diseases that originally only infect animals, but have affected humans. SPILLOVER EVENT is when the disease actually transmits to humans. Diseases that Changed History ----------------------------- - - - - - - One Health Theory ----------------- The ONE HEALTH THEORY is that if humans take care of the environment and ourselves, it won't spillover to other living organisms. LESSON 4 - BACTERIA AND VIRUSES =============================== Bacteria -------- - - Only 1-10% have been discovered. Our body has more bacteria cells than human cells. - - Structure of Bacteria --------------------- - - - - Bacterial Organization ---------------------- They can appear in the following: - - - - - Their shapes can be: - - - Diseases Caused by Bacteria --------------------------- - - - - - - - - - - Bacterial Reproduction ---------------------- CELL DIVISION is when one cell duplicates a set of DNA then starts splitting themselves in half to make a second cell. CONJUGATION is the sexual reproduction done by bacteria. Under stress, a bacterium with plasmid will connect with one without through the pilus to transmit the plasmid over. Then these two bacteria will both be positive (contains plasmid) to continue reproducing. Bacterial growth is EXPONENTIAL, meaning that one single cell can reproduce themselves in 20-30 minutes, producing large colonies of cells in a mere few hours. To prevent exponential growth, provide them with a colder environment. Viruses ------- - - - Structure of Virus ------------------ - - - - Virus Replication ----------------- - - - Viruses have spike proteins that match to a specific molecule on the outside of the membrane of a cell. The protein and the host fits together and the virus injects the genetic material into the host cell for it to replicate. Once the host cell is infected, it dies and explodes to spread the virus to other cells. Diseases Caused by Viruses -------------------------- - - - - - - - - - LESSON 5 - BREAKING THE INFECTIOUS DISEASE CYCLE ================================================ Infectious Disease Cycle ------------------------ 1. 2. 3. 4. 5. Defender's (Immune System) Response ----------------------------------- FIRST LINE OF DEFENCE (PHYSICAL BARRIERS): - - - - - - FIRST LINE OF DEFENCE (CHEMICAL BARRIERS): - - - - SECOND LINE OF DEFENCE: Macrophages surrounds and eats foreign objects. Antibodies like lymphocytes gain memory for antigens on pathogens. Medicines that Kill Pathogens ----------------------------- ANTIBIOTICS are substances that destroy or slow down the production of bacteria, but not viruses. ANTIVIRAL medications are able to destroy some viruses. ANTIBIOTIC RESISTANCE is when a bacteria gains the ability to resist the drugs that is supposed to kill them. To prevent antibiotic resistance, you should only use antibiotics against bacteria because it won't work for viruses. Also take all your medications even if you are feeling better. Ways to Prevent Illnesses ------------------------- VACCINES are substances that are used to stimulate our immune system from weakened or dead forms of the disease. These are usually used against viruses and only some bacteria. They also only prevent the illness but doesn't cure. It is a small fragment of the a new antigen so that our body will know how to make an antibody against the pathogen. LESSON 6 - TRANSMISSION AND PREVENTION ====================================== Ways that Diseases are Transmitted ---------------------------------- - Droplets - Airborne (aerosols) - Direct contact with people - Indirect contact with people - Direct contact with animals - Vehicles - Vectors Prevention Methods ------------------ - Cover your mouth and nose for sneezing and coughing - Physical distance - Protective clothing (masks, long sleeves) - Wash your hands after handling animals - Quarantine - Disinfection - Food safety - Vaccinate sick animals and yourself - Clean water and good sanitation LESSON 7 - DISEASE IN POPULATION ================================ PANDEMIC is a worldwide spread of a disease.Examples are COVID, SARS, and Black death. ENDEMIC is a constant appearance of a disease that affects a specific geographical area, like Malaria. EPIDEMIC is a drastic increase in a disease in a local community. Examples would be the Flu. EPIDEMIOLOGISTS study the cases of disease in a population. Conditions that Cause Pandemics ------------------------------- - Global warming - Travelling - Crowded cities - Close proximity to animals - Grand population Consequences of Pandemics ------------------------- - Grief, poverty, and hunger - Death - Loss of employment - Shortage of workers - Cities rebuilding Preventing Pandemics -------------------- Ensure that people have healthy living conditions and to give out immunization programs. HERD IMMUNITY is when most of the population is vaccinated to keep the small amount of the population away from the virus. Proper hygiene for yourself is also important, like washing your hands, small social circles, social distancing, wear masks properly, isolation, etc. Also, think critically about information and act appropriately. When a disease is no longer endemic, it is eliminated. If it is completely gone, it is eradicated. LESSON 8 - VACCINE HESITANCY ============================ Vaccine hesitancy is the refusal to take a vaccine. This threatens the reverse progress of tackling vaccine-preventable diseases. Reasons Why Vaccine Hesitancy Exists ------------------------------------ - People just don't bother. - Inconvenience to access vaccines. - Lacks confidence in science. - Conflicting belief system (religion). - Pseudoscience