Question 1

What are the primary lines of defense against infectious diseases in the human body?

Accepted Answer

The human body has three primary lines of defense against infectious diseases. The first line includes physical and chemical barriers such as skin and mucous membranes that prevent pathogens from entering. The second line involves non-specific immune responses like inflammation and phagocytosis by white blood cells. The third line is the specific immune response, where lymphocytes produce antibodies tailored to specific pathogens. This is a key concept in the IB DP Biology curriculum under Human Physiology.

Question 2

How do vaccines contribute to the defense against infectious diseases?

Accepted Answer

Vaccines play a crucial role in the defense against infectious diseases by stimulating the body's immune system to recognize and fight pathogens. They contain antigens that mimic disease-causing organisms, prompting the immune system to produce memory cells. This prepares the body to respond more effectively and quickly if exposed to the actual pathogen in the future. Understanding vaccines is essential for IB DP Biology students studying Human Physiology.

Question 3

What is the role of antibodies in the immune response?

Accepted Answer

Antibodies are proteins produced by B lymphocytes in response to specific antigens. They play a vital role in the immune response by neutralizing pathogens, marking them for destruction by other immune cells, and preventing their spread. Antibodies are a key component of the adaptive immune system, which is a major topic in the IB DP Biology curriculum under Defence against infectious diseases.

Question 4

How does the inflammatory response help in fighting infections?

Accepted Answer

The inflammatory response is a non-specific defense mechanism that occurs when tissues are injured by bacteria, trauma, toxins, or other causes. It involves the release of chemicals like histamines that increase blood flow to the affected area, bringing more immune cells to fight the infection. This response helps isolate the pathogen and facilitates the healing process. Understanding inflammation is important for IB DP students studying Human Physiology.

Question 5

Why is the study of pathogens important in understanding infectious diseases?

Accepted Answer

Studying pathogens is crucial for understanding infectious diseases because it helps identify the organisms that cause diseases, their modes of transmission, and how they interact with the host's immune system. This knowledge is essential for developing effective treatments and preventive measures. In the IB DP Biology curriculum, learning about pathogens is integral to mastering the topic of Defence against infectious diseases.

Defence against infectious diseases

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