AQA GCSE Infection and Response Knowledge Organiser PDF - Biology Revision, Communicable Diseases

Page 2: Plant Diseases, Defenses, and Human Immune System

This page focuses on plant diseases, plant defense mechanisms, and the human body's defense systems against pathogens.

Plant Diseases and Defenses:

• Common signs of plant diseases include stunted growth, leaf spots, and discoloration
• Plants have physical, chemical, and mechanical defenses against pathogens

Example: Physical plant defenses include a waxy cuticle and cell walls, while mechanical defenses can include thorns and hairs.

Human Defense Systems:

1. Skin barrier
2. Nose hairs and mucus
3. Trachea and bronchi with mucus and cilia
4. Stomach acid

The Immune System:

• White blood cells play a crucial role in fighting pathogens
• Phagocytosis, antitoxin production, and antibody creation are key processes

Definition: Phagocytosis is the process where white blood cells engulf and digest pathogens.

Vaccinations:

• The page begins to discuss vaccinations but is cut off

Highlight: Antibodies are specific to one antigen and will only work on that particular pathogen.

Page 3: Incomplete Information

The transcript for page 3 is incomplete, ending mid-sentence while discussing vaccinations. Without the full content, a comprehensive summary cannot be provided for this page.

Highlight: The incomplete information suggests that the full document likely contains more details about vaccinations and possibly other methods of fighting diseases.

Page 1: Communicable Diseases and Pathogens

This page introduces the concept of communicable diseases and the various types of pathogens that cause them. It covers viral, bacterial, fungal, and protist diseases, as well as methods of pathogen transmission.

Definition: Pathogens are microorganisms that enter the body and cause communicable (infectious) diseases in plants and animals.

The page details specific diseases caused by different pathogens:

Viral Diseases:

• Measles: Spread through droplets, causing rashes and fever
• HIV: Transmitted through bodily fluids, attacking the immune system
• Tobacco mosaic virus: Affects plants, discoloring leaves

Bacterial Diseases:

• Salmonella: Causes food poisoning with symptoms like fever and stomach cramps
• Gonorrhoea: A sexually transmitted infection with symptoms including pain when urinating

Highlight: Bacteria produce toxins that make you feel ill by damaging cells and tissues, while viruses replicate inside cells before bursting out to release new viruses.

Fungal and Protist Diseases:

• Rose black spot: A fungal disease affecting plant leaves
• Malaria: A protist disease transmitted by mosquitoes

The page also outlines methods to prevent the spread of pathogens, including hygiene practices, vector control, isolation, and vaccination.

Vocabulary: Vectors are organisms that transmit pathogens between hosts.