Diseases and Immunity

Question 1

Pathogen

Answer 1

A disease-causing organism.

Question 2

Transmissible Disease

Answer 2

A disease in which the pathogen can be passed from one host to another.

Question 3

Ways Pathogens Are Transmitted

Answer 3

Direct Contact: Through blood, body fluids, etc.
Indirect Contact: Via contaminated surfaces, food, animals, or air.

Question 4

Features of Viruses

Answer 4

Viruses have a protein coat and genetic material.

Question 5

Body Defenses Against Pathogens

Answer 5

Mechanical Barriers:
Nostrils: Hairs trap dust.
Skin: Outer layer of dead cells blocks pathogens.
Chemical Barriers:
Mucus: Traps pathogens.
Stomach Acid: Kills many bacteria.
Cells:
Phagocytosis: White blood cells engulf and digest pathogens.
Antibodies: Produced to mark or destroy pathogens.
Vaccination: Helps antibodies be made quickly.

Question 6

Controlling the Spread of Diseases

Answer 6

A Clean Water Supply
Hygienic Food Preparation
Good Personal Hygiene
Waste Disposal
Sewage Treatment

Question 7

Active Immunity

Answer 7

Definition: Immunity gained by producing antibodies after infection or vaccination.
Vaccination:
Introduces weakened pathogens or antigens.
Stimulates immune response by lymphocytes.
Produces memory cells for long-term immunity.

Question 8

Passive Immunity

Answer 8

Definition: Short-term immunity passed from another individual, like from mother to baby through breast milk.
No Memory Cells: Unlike active immunity, no memory cells are made.

Question 9

Antibodies

Answer 9

Definition: Proteins that bind to antigens, marking or destroying pathogens.
Specificity: Each antibody fits a specific antigen.

Question 10

Cholera

Answer 10

Cause: Bacterium Vibrio cholerae.
Symptoms: Diarrhea, dehydration, loss of salts from blood.
Treatment: Oral rehydration therapy, antibiotics.

Question 11

Features of Viruses

Answer 11

Consist of a protein coat and genetic material.

Question 12

Active Immunity vs. Passive Immunity

Answer 12

Active Immunity:
Gained after infection or vaccination.
Long-term protection due to memory cells.
Passive Immunity:
Temporary, acquired through antibodies from another individual.
No memory cells made.

Question 13

The Process of Vaccination

Answer 13

Step 1: Introduce weakened pathogens or antigens into the body.
Step 2: Lymphocytes produce antibodies in response.
Step 3: Memory cells are produced, offering long-term immunity.

Question 14

Immunity and Disease Control

Answer 14

Vaccinations help control the spread of diseases by providing immunity without the risk of infection.

Question 15

White Blood Cells

Answer 15

Phagocytes:
Have lobed nuclei.
Engulf and digest pathogens.
Lymphocytes:
Produce antibodies.
Have a circular nucleus, responsible for antibody production.

Question 16

Antigen-Antibody Interaction

Answer 16

Antigens: Protein/carbohydrate markers on the surface of pathogens.
Antibodies: Bind to antigens and help destroy or mark pathogens for destruction by phagocytes.

Question 17

The Role of Antibodies

Answer 17

Function: Bind to antigens, marking pathogens for destruction or directly destroying them.

Question 18

Importance of Vaccination

Answer 18

Helps control disease spread.
Creates herd immunity when a large portion of the population is vaccinated.

Question 19

Controlling Cholera

Answer 19

Cause: Vibrio cholerae bacterium in contaminated water.
Effect: Toxin causes dehydration and diarrhea.
Treatment: Rehydration and antibiotics.

Question 20

Features of Each Pathogen

Answer 20

Viruses: Have protein coats and genetic material.
Bacteria: Single-celled organisms with no membrane-bound organelles, often treated with antibiotics.

Question 21

Disease Control

Answer 21

Clean Water Supply: Prevents pathogen transmission through water.
Hygienic Food Preparation: Reduces pathogen contamination in food.
Personal Hygiene: Reduces pathogen transfer via direct contact.
Waste Disposal: Prevents contamination of the environment.
Sewage Treatment: Helps eliminate pathogens from waste water.

Question 22

Active Immunity

Answer 22

Definition: Immunity gained through exposure to pathogens either naturally or through vaccination.
Long-Term Protection: Memory cells are produced, enabling faster response upon future exposure.

Question 23

Passive Immunity

Answer 23

Definition: Immunity passed from one individual to another.
Temporary: No memory cells are produced, and protection lasts only as long as the antibodies are present.

Question 24

Immune System and Disease

Answer 24

Phagocytosis: White blood cells engulf and digest pathogens.
Antibody Production: Lymphocytes produce antibodies that target specific antigens on pathogens.

Question 25

Vaccination Process

Answer 25

Weakened or Killed Pathogens/Antigens: Introduced to the body.
Immune Response: Lymphocytes create antibodies, and memory cells are formed for future protection.