Biology Lesson 1 - Cell Theory and Diseases

Lesson 1 - Cell Theory

• Living things are composed of cells
• Cells are made up of complex substances and components
• Cells reproduce
• Cells use and make energy
• Cells grow and develop
• Cells evolve over time
• Cells produce waste
• Cells have a definite form and limited size
• Cells have a limited lifespan
• Cells adapt to their environment

Cell Theory (Original)

• Cells are the basic units of life
• Cells come from pre-existing cells
• All living things are composed of cells and the products of cells

Cell Theory (Modern)

• Energy flows within cells
• DNA is passed from cell to cell
• All components are made from similar chemical compositions

Spontaneous Generation (Abiogenesis)

• The idea that living things can arise from non-living matter
• Disproven by experiments like those of Francesco Redi

Lesson 3 - Infectious Diseases

• Diseases are abnormal conditions with symptoms
• Symptoms include physical and chemical changes
• Factors that cause diseases include injuries, genetics, stress, lifestyle, diet, and pathogens
• Pathogens are microbes that cause diseases by infecting a host
• Infections are how pathogens manifest in a host
• Examples of pathogens include parasites, bacteria, viruses, fungi, and protozoa.
• Zoonotic diseases originate in animals but can affect humans (spillover event)
• Examples of historically significant diseases include the Black Death, smallpox, cholera, yellow fever, syphilis, and hemophilia
• One Health Theory: Human health is intertwined with animal and environmental health

Lesson 4 - Bacteria and Viruses

• Bacteria are the oldest and most abundant living organisms
• Most bacteria are beneficial, but a small percentage (1-10%) are harmful
• Bacteria structure is prokaryotic and unicellular
• Lacks membrane-bound organelles (e.g., nucleus, mitochondria)
• Contains other organelles (e.g., ribosomes, DNA)
• Bacteria can be organized as single cells, pairs (diplo), chains (strepto), clusters (staphylo), or colonies
• Bacteria shapes include rod-shaped (bacillus), dot-shaped (cocci), and spiral-shaped (spirilla)
• Examples of diseases caused by bacteria include the plague, cholera, and yellow fever

Lesson 5 - Breaking the Infectious Disease Cycle

• Infectious disease cycle involves transmission, entry, multiplication, cell damage, and alerts immune system.
• First line of defense is physical barriers like skin, mucus and chemical barriers such as saliva and tears
• Second line of defense involves the immune system's response

Lesson 6 - Transmission and Prevention

• Diseases are transmitted through droplets, airborne particles (aerosols), direct contact, indirect contact, animal contact, or vehicles
• Prevention methods involve covering mouth/nose, physical distance, protective clothing, handwashing, quarantine, disinfection, food safety, vaccination of animals and humans, clean water and sanitation

Lesson 7 - Disease in Populations

• Pandemic: a widespread disease globally
• Endemic: a disease consistently present in a geographical area
• Epidemic: a dramatic increase in disease within a community
• Epidemiologists study the patterns of disease occurrence in populations
• Conditions that may lead to pandemics include global warming, travel, crowding, and close proximity to animals
• Pandemic consequences include grief, poverty, hunger, loss of life, economic hardship, and societal disruption
• Preventing pandemics is achieved by good hygiene, living conditions, and immunizations

Lesson 8 - Vaccine Hesitancy

• Vaccine hesitancy is a resistance to getting vaccines
• Reasons for hesitancy include lack of concern, inconvenience, doubt in science, conflicting personal beliefs, and pseudoscience

Explore the fundamental concepts of cell theory and its modern interpretations, including the origin of cells and the disproval of spontaneous generation. Additionally, learn about infectious diseases and their characteristics as abnormal conditions. This quiz covers essential biological principles and their implications in the living world.