Human Biology - 4HB1 PearsonEdexcel

Pathogens And Disease Transmission

Overview

An outbreak of cholera in a city with poor sanitation, an athlete picking up a fungal infection in a shared changing room, and malaria spreading through a region with stagnant water all look like unrelated problems, but each follows directly from the biology of the organism responsible and the route it uses to reach a new host.

This lesson covers how infectious disease develops in a person, the structure and biology of viruses and bacteria, and the specific transmission, treatment and prevention of six named diseases: Ebola, HIV, cholera, gonorrhoea, athlete's foot, malaria and typhoid, including the roles of the mosquito and housefly as disease vectors.

Objectives

  1. Understand the general course of a disease as: infection, incubation and symptoms
  2. Know that diseases are caused by pathogenic microorganisms
  3. Describe the structure and reproduction of viruses
  4. Describe methods of transmission, treatment and prevention of the spread of Ebola and HIV (human immuno-deficiency virus), the virus that causes AIDS
  5. Describe the structure, nutrition and reproduction of bacteria including the interpretation of bacterial growth curves
  6. Investigate the effects of antibacterial agents and antibiotics on the growth of bacterial culture
  7. Know the methods of transmission, treatment and prevention of the spread of cholera and gonorrhoea
  8. Explain the importance of oral rehydration therapy
  9. Know the methods of transmission, treatment and prevention of the spread of athlete's foot
  10. Explain the role of the mosquito (malaria) and housefly (typhoid) in transmitting causative agents of disease
  11. Describe the treatment and prevention of the spread of malaria and typhoid

Lesson Note

An infectious disease follows a general course once a pathogen, a microorganism capable of causing disease, enters the body. First is infection: the pathogen establishes itself in the host and begins to multiply. This is followed by an incubation period, the interval during which the pathogen multiplies but the host shows no obvious symptoms, even though they may already be able to pass the infection on. Finally, symptoms appear once the pathogen population, or the toxins and tissue damage it causes, becomes large enough for the body to react visibly.

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Lesson Evaluation

Congratulations on completing the lesson on Pathogens And Disease Transmission. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

  1. Which stage of a disease occurs when a pathogen is multiplying in the body but no symptoms are yet visible? A) Infection B) Incubation period C) Symptomatic stage D) Recovery Answer: B
  2. Which organism acts as the vector for malaria? A) Housefly B) Anopheles mosquito C) Bacterium D) Fungus Answer: B
  3. What type of pathogen causes athlete's foot? A) Virus B) Bacterium C) Fungus D) Parasite Answer: C
  4. Which phase of bacterial growth shows a constant rate of cell division and a steep rise in numbers? A) Lag phase B) Exponential (log) phase C) Stationary phase D) Death phase Answer: B
  5. Oral rehydration therapy is used mainly to treat the effects of which disease? A) Malaria B) Athlete's foot C) Cholera D) HIV Answer: C

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Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
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Available on Android, Windows, macOS, and Linux

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
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Study offline, anytime, anywhere
Available on Android, Windows, macOS, and Linux

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