3.1.1
Spreading Disease
Pathogens and Infections
Pathogens and Infections
Infections are caused whenever a foreign pathogen invades an organism (animal or plant). There are four main types of pathogen:
![Illustrative background for Viruses](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.2.1%20Chromosomes%20and%20mitosis/virus-1812092_640,h_400,q_80,w_640.jpg)
![Illustrative background for Viruses ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.2.1%20Chromosomes%20and%20mitosis/virus-1812092_640,h_400,q_80,w_640.jpg)
Viruses
Viruses
- Viruses are tiny, non-living (do not contain cells) particles that can reproduce rapidly within the body.
- They invade host cells and use them to make new virus particles.
- Once the new viruses are made, they cause the cells to burst.
- The cell damage makes us feel ill.
![Illustrative background for Bacteria](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.1.1%20-%20Types%20of%20cells/bacteria,h_400,q_80,w_640.jpg)
![Illustrative background for Bacteria ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.1.1%20-%20Types%20of%20cells/bacteria,h_400,q_80,w_640.jpg)
Bacteria
Bacteria
- Bacteria are small living cells that either damage cells directly or by producing toxins (poisons).
- Bacteria can reproduce rapidly in the appropriate conditions: warm, moist areas with a good supply of oxygen.
- The toxins released by bacteria can damage cells and tissues, making us feel ill.
![Illustrative background for Fungi](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.1.1%20-%20Types%20of%20cells/fungus,h_400,q_80,w_640.jpg)
![Illustrative background for Fungi ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.1.1%20-%20Types%20of%20cells/fungus,h_400,q_80,w_640.jpg)
Fungi
Fungi
- Some fungi are single-celled organisms that have a body made up of hyphae (thread-like structures).
- The hyphae are able to grow and penetrate tissues, such as human skin or the surface of plants.
- The hyphae produce spores that can spread to other plants and animals.
![Illustrative background for Protists](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.1.1%20-%20Types%20of%20cells/protist,h_400,q_80,w_640.jpg)
![Illustrative background for Protists ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.1.1%20-%20Types%20of%20cells/protist,h_400,q_80,w_640.jpg)
Protists
Protists
- Protists are single-celled eukaryotic organisms (they have a nucleus).
- Many are parasites, meaning that they live on or inside other organisms.
- They are often transferred to the host organism by a vector, such as an insect or mosquito.
- They make us feel ill by damaging our tissues.
Spreading Disease
Spreading Disease
There are three ways an infectious disease can spread:
![Illustrative background for Direct contact](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/1.1.4/hands-2847508_640%20(1)-min,h_400,q_80,w_640.jpg)
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Direct contact
Direct contact
- Some pathogens live on the surface of other organisms, such as the skin. If infected skin touches a surface, some of the pathogens can transfer from the infected skin to the surface.
- The pathogen then spreads to other people who also touch that surface. Athlete's foot is spread in this way.
![Illustrative background for Water](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/water-2820855_640-min,h_400,q_80,w_640.jpg)
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Water
Water
- Some pathogens contaminate water supplies. Organisms drinking this contaminated water can be infected by pathogens.
- Cholera is a disease spread in this way.
![Illustrative background for Air](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/sneeze-min,h_400,q_80,w_640.jpg)
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Air
Air
- Some pathogens are released into the air inside droplets when an organism coughs or sneezes. These droplets can then be inhaled (breathed in) by other organisms.
- The flu and common colds are spread in this way.
Preventing Infection Spread
Preventing Infection Spread
The spread of infections can be prevented by being hygienic, by isolating infected individuals, by protecting against vectors and by vaccination.
![Illustrative background for Hygiene](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/hands-2238235_640-min,h_400,q_80,w_640.jpg)
![Illustrative background for Hygiene ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/hands-2238235_640-min,h_400,q_80,w_640.jpg)
Hygiene
Hygiene
- By being hygienic, we can destroy pathogens or wash them away so that they are not spread.
- Using antibacterial products to clean surfaces, washing our hands and sneezing into a handkerchief are all hygienic measures to prevent the spread of infection.
![Illustrative background for Isolation](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/isolation,h_400,q_80,w_640.jpg)
![Illustrative background for Isolation ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/isolation,h_400,q_80,w_640.jpg)
Isolation
Isolation
- By isolating infected individuals, we prevent contact with other organisms. This stops the infection from spreading.
![Illustrative background for Disease vectors](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/mosquito-1332382_640-min,h_400,q_80,w_640.jpg)
![Illustrative background for Disease vectors ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/mosquito-1332382_640-min,h_400,q_80,w_640.jpg)
Disease vectors
Disease vectors
- Some protist diseases are carried by vectors.
- A vector is an organism that carries pathogens without being infected.
- For example, we can protect against mosquitos carrying malaria using mosquito nets.
![Illustrative background for Vaccination](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/vaccination-2722937_640-min,h_400,q_80,w_640.jpg)
![Illustrative background for Vaccination ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/vaccination-2722937_640-min,h_400,q_80,w_640.jpg)
Vaccination
Vaccination
- Vaccination can make people immune to (resistant to) infection.
- The more individuals that are vaccinated, the less likely the disease is to spread.
1Cell Biology
1.1What's in Cells?
1.1.1Types of Cells
1.1.2Properties of Prokaryotes
1.1.3Standard Form
1.1.4Standard Form - Calculations
1.1.5Addition in Standard Form - Calculations
1.1.6Subtraction in Standard Form - Calculations
1.1.7Multiplication in Standard Form - Calculations
1.1.8Division in Standard Form - Calculations
1.1.9Animal Cells
1.1.10Plant Cells
1.1.11Differences Between Animal & Plant Cells
1.1.12Bacterial Cells
1.1.13Types of Cells HyperLearning
1.1.14Cell Specialisation in Animals
1.1.15Sperm Cells
1.1.16Nerve Cells
1.1.17Muscle Cells
1.1.18Cell Specialisation in Plants
1.1.19Microscopy
1.1.20Developments in Microscopy
1.1.21Microscope Practical
1.1.22Microscopy - Calculations
1.1.23Culturing Microorganisms
1.1.24Contamination
1.1.25Avoiding Contamination
1.1.26Calculating Bacteria
1.1.27Calculating Bacteria - Calculations
1.1.28End of Topic Test - What's in Cells?
1.1.29Exam-Style Questions - Cell Structure & Microscopy
1.2Cell Division
1.3Transport in Cells
1.3.1Diffusion
1.3.2Factors Affecting Diffusion
1.3.3Surface Area : Volume
1.3.4Surface Area : Volume - Calculations
1.3.5Exchange Surfaces
1.3.6Examples of Exchange Surfaces
1.3.7Osmosis
1.3.8Osmosis Practical
1.3.9Active Transport
1.3.10Transport in Cells
1.3.11End of Topic Test - Cell Division & Transport
1.3.12Grade 9 - Cell Transport
2Organisation
2.1Principles of Organisation
2.2Enzymes
2.2.1Enzymes
2.2.2Enzymes HyperFlashcards
2.2.3Rate of Reaction
2.2.4Calculating Rate of Reaction
2.2.5Rate of Reaction - Calculations
2.2.6Digestion
2.2.7Bile
2.2.8Examples of Digestive Enzymes - Amylase
2.2.9Examples of Digestive Enzymes - Protease
2.2.10Examples of Digestive Enzymes - Lipase
2.2.11Testing for Biological Molecules
2.2.12End of Topic Test - Organisation & Enzymes
2.2.13Grade 9 - Enzymes
2.2.14Exam-Style Questions - Enzymes
2.3Circulatory System
2.3.1Types of Blood Vessel
2.3.2Blood Vessels - Arteries
2.3.3Blood Vessels - Capillaries
2.3.4Blood Vessels - Veins
2.3.5The Heart - Structure
2.3.6The Heart - Function
2.3.7Important Blood Vessels
2.3.8Double Circulatory System
2.3.9Gas Exchange
2.3.10Gas exchange - Calculations
2.3.11Alveoli
2.3.12Blood Components
2.3.13Platelets
2.3.14Red Blood Cells
2.3.15White Blood Cells
2.3.16End of Topic Test - Circulatory System
2.4Non-Communicable Diseases
2.4.1Health Issues
2.4.2Disease Interactions
2.4.3Sampling
2.4.4Sampling - Calculations
2.4.5Risk Factors
2.4.6Examples of Risk Factors
2.4.7Risk Factor Graphs
2.4.8Coronary Heart Disease
2.4.9Heart Valve Disease
2.4.10Heart Failure
2.4.11Treating Heart Disease
2.4.12Cancer
2.4.13Cancer Risk Factors
2.4.14End of Topic Test - Non-Communicable Diseases
2.4.15Exam-Style Questions - Coronary Heart Disease
2.5Plant Tissues, Organs & Systems
3Infection & Response
3.1Communicable Disease
3.1.1Spreading Disease
3.1.2Viruses
3.1.3Other Pathogens
3.1.4Human Defence Systems
3.1.5Human Defence Systems 2
3.1.6Grade 9 - Immune System
3.1.7Antibiotics
3.1.8Drug Development
3.1.9Drug Testing
3.1.10Drug Testing / Efficacy - Calculations
3.1.11End of Topic Test - Communicable Diseases
3.1.12Exam-Style Questions - Microorganisms & Disease
3.2Monoclonal Antibodies
4Bioenergetics
4.1Photosynthesis
5Homeostasis & Response
5.1Homeostasis
5.2The Human Nervous System
5.2.1The Nervous System
5.2.2The Nervous System HyperFlashcards
5.2.3Synapses
5.2.4Reflexes
5.2.5Exam-Style Questions - Nervous System
5.2.6The Brain
5.2.7Eye Anatomy
5.2.8Eye Function
5.2.9Control of Body Temperature
5.2.10Warming Up & Cooling Down
5.2.11Body Temperature HyperLearning
5.2.12End of Topic Test - Human Nervous System
5.3Hormonal Coordination in Humans
5.3.1Endocrine System
5.3.2Thyroxine & Adrenaline
5.3.3Blood Glucose
5.3.4Diabetes
5.3.5Control of Water Balance
5.3.6Urine
5.3.7Dialysis
5.3.8Transplants
5.3.9Puberty
5.3.10Menstruation
5.3.11Contraception
5.3.12Contraception 2
5.3.13Hormones for Infertility
5.3.14End of Topic Test - Homeostasis & Hormones
5.3.15Grade 9 - Hormonal Coordination
5.3.16Exam-Style Questions - Hormones & Contraception
6Inheritance, Variation & Evolution
6.1Reproduction
6.1.1Reproduction
6.1.2Reproduction 2
6.1.3Genome
6.1.4DNA
6.1.5Protein Synthesis
6.1.6Genetic Inheritance
6.1.7Genetic Crosses
6.1.8Inherited Disorders
6.1.9Inherited Disorders 2
6.1.10Genetic Crosses - Calculations
6.1.11Genome Screening & Sex Determination
6.1.12End of Topic Test - Reproduction
6.1.13Exam-Style Questions - DNA & Genetics
6.2Variation & Evolution
6.3Genetics & Evolution
7Ecology
7.1Adaptations & Interdependence
7.2Organisation of Ecosystems
7.3Biodiversity
7.4Trophic Levels
Jump to other topics
1Cell Biology
1.1What's in Cells?
1.1.1Types of Cells
1.1.2Properties of Prokaryotes
1.1.3Standard Form
1.1.4Standard Form - Calculations
1.1.5Addition in Standard Form - Calculations
1.1.6Subtraction in Standard Form - Calculations
1.1.7Multiplication in Standard Form - Calculations
1.1.8Division in Standard Form - Calculations
1.1.9Animal Cells
1.1.10Plant Cells
1.1.11Differences Between Animal & Plant Cells
1.1.12Bacterial Cells
1.1.13Types of Cells HyperLearning
1.1.14Cell Specialisation in Animals
1.1.15Sperm Cells
1.1.16Nerve Cells
1.1.17Muscle Cells
1.1.18Cell Specialisation in Plants
1.1.19Microscopy
1.1.20Developments in Microscopy
1.1.21Microscope Practical
1.1.22Microscopy - Calculations
1.1.23Culturing Microorganisms
1.1.24Contamination
1.1.25Avoiding Contamination
1.1.26Calculating Bacteria
1.1.27Calculating Bacteria - Calculations
1.1.28End of Topic Test - What's in Cells?
1.1.29Exam-Style Questions - Cell Structure & Microscopy
1.2Cell Division
1.3Transport in Cells
1.3.1Diffusion
1.3.2Factors Affecting Diffusion
1.3.3Surface Area : Volume
1.3.4Surface Area : Volume - Calculations
1.3.5Exchange Surfaces
1.3.6Examples of Exchange Surfaces
1.3.7Osmosis
1.3.8Osmosis Practical
1.3.9Active Transport
1.3.10Transport in Cells
1.3.11End of Topic Test - Cell Division & Transport
1.3.12Grade 9 - Cell Transport
2Organisation
2.1Principles of Organisation
2.2Enzymes
2.2.1Enzymes
2.2.2Enzymes HyperFlashcards
2.2.3Rate of Reaction
2.2.4Calculating Rate of Reaction
2.2.5Rate of Reaction - Calculations
2.2.6Digestion
2.2.7Bile
2.2.8Examples of Digestive Enzymes - Amylase
2.2.9Examples of Digestive Enzymes - Protease
2.2.10Examples of Digestive Enzymes - Lipase
2.2.11Testing for Biological Molecules
2.2.12End of Topic Test - Organisation & Enzymes
2.2.13Grade 9 - Enzymes
2.2.14Exam-Style Questions - Enzymes
2.3Circulatory System
2.3.1Types of Blood Vessel
2.3.2Blood Vessels - Arteries
2.3.3Blood Vessels - Capillaries
2.3.4Blood Vessels - Veins
2.3.5The Heart - Structure
2.3.6The Heart - Function
2.3.7Important Blood Vessels
2.3.8Double Circulatory System
2.3.9Gas Exchange
2.3.10Gas exchange - Calculations
2.3.11Alveoli
2.3.12Blood Components
2.3.13Platelets
2.3.14Red Blood Cells
2.3.15White Blood Cells
2.3.16End of Topic Test - Circulatory System
2.4Non-Communicable Diseases
2.4.1Health Issues
2.4.2Disease Interactions
2.4.3Sampling
2.4.4Sampling - Calculations
2.4.5Risk Factors
2.4.6Examples of Risk Factors
2.4.7Risk Factor Graphs
2.4.8Coronary Heart Disease
2.4.9Heart Valve Disease
2.4.10Heart Failure
2.4.11Treating Heart Disease
2.4.12Cancer
2.4.13Cancer Risk Factors
2.4.14End of Topic Test - Non-Communicable Diseases
2.4.15Exam-Style Questions - Coronary Heart Disease
2.5Plant Tissues, Organs & Systems
3Infection & Response
3.1Communicable Disease
3.1.1Spreading Disease
3.1.2Viruses
3.1.3Other Pathogens
3.1.4Human Defence Systems
3.1.5Human Defence Systems 2
3.1.6Grade 9 - Immune System
3.1.7Antibiotics
3.1.8Drug Development
3.1.9Drug Testing
3.1.10Drug Testing / Efficacy - Calculations
3.1.11End of Topic Test - Communicable Diseases
3.1.12Exam-Style Questions - Microorganisms & Disease
3.2Monoclonal Antibodies
4Bioenergetics
4.1Photosynthesis
5Homeostasis & Response
5.1Homeostasis
5.2The Human Nervous System
5.2.1The Nervous System
5.2.2The Nervous System HyperFlashcards
5.2.3Synapses
5.2.4Reflexes
5.2.5Exam-Style Questions - Nervous System
5.2.6The Brain
5.2.7Eye Anatomy
5.2.8Eye Function
5.2.9Control of Body Temperature
5.2.10Warming Up & Cooling Down
5.2.11Body Temperature HyperLearning
5.2.12End of Topic Test - Human Nervous System
5.3Hormonal Coordination in Humans
5.3.1Endocrine System
5.3.2Thyroxine & Adrenaline
5.3.3Blood Glucose
5.3.4Diabetes
5.3.5Control of Water Balance
5.3.6Urine
5.3.7Dialysis
5.3.8Transplants
5.3.9Puberty
5.3.10Menstruation
5.3.11Contraception
5.3.12Contraception 2
5.3.13Hormones for Infertility
5.3.14End of Topic Test - Homeostasis & Hormones
5.3.15Grade 9 - Hormonal Coordination
5.3.16Exam-Style Questions - Hormones & Contraception
6Inheritance, Variation & Evolution
6.1Reproduction
6.1.1Reproduction
6.1.2Reproduction 2
6.1.3Genome
6.1.4DNA
6.1.5Protein Synthesis
6.1.6Genetic Inheritance
6.1.7Genetic Crosses
6.1.8Inherited Disorders
6.1.9Inherited Disorders 2
6.1.10Genetic Crosses - Calculations
6.1.11Genome Screening & Sex Determination
6.1.12End of Topic Test - Reproduction
6.1.13Exam-Style Questions - DNA & Genetics
6.2Variation & Evolution
6.3Genetics & Evolution
7Ecology
7.1Adaptations & Interdependence
7.2Organisation of Ecosystems
7.3Biodiversity
7.4Trophic Levels
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