Chapter 10- Diseases and Immunity

Question 1

What are pathogens?

Answer 1

A microorganism that can cause a disease

Question 2

What are hosts?

Answer 2

An organism where a pathogen lives and reproduces

Question 3

What are transmissible diseases?

Answer 3

A disease that can be passed from one host to another, these diseases are caused by pathogens.

Question 3

What are the different pathogens and what diseases do they cause

Answer 3

Virus- Influenza, common cold, AIDS, measels, polythelitis
Bacteria- Cholera, Syphillus, Tetnus, Tubercolosis, whooping cough
Protocists- malaria, ameobic dysentry
Fungi- athlete’s foot, ringworm

Question 4

What is toxins and symptoms, and why are the caused?

Answer 4

Once a pathogen enters a body, it damages the cells, by using up all the resources. It also harms cells and body parts, by releasing a waste product called Toxin, toxins spread over your body, causing symptoms.
Toxins: A poisonous substances, chemical that damages a cell
Symptoms: Features that you experience after getting a disease

Question 5

What is transmission, and infection

Answer 5

Transmission: The movement of a pathogen from one body to another.
Infection: The entry of a pathogen into a new host.

Question 6

What is indirect transmission?

Answer 6

• Breathing in droplets of moisture than contains a pathogen
• Touching something that a person who has a pathogen touched
• Eating food or drink, that contain a pathogen
• Being near animals that contain the pathogen

Question 7

What are the various different natural defenses in our body?

Answer 7

• our skin protects the pathogen from entering, if our skin breaks, blood clots immediately cover it up, preventing pathogens from entering.
• ## the mucus in our body prevents bacteria from entering the lungs, and traps the bacteria, and pushes it back into the throat, so that it can be swallowed and won’t enter the lungs

Question 7

What are the various different natural defenses in our body?

Answer 7

• our skin protects the pathogen from entering, if our skin breaks, blood clots immediately cover it up, preventing pathogens from entering.
• the mucus in our body prevents bacteria from entering the lungs, and traps the bacteria, and pushes it back into the throat, so that it can be swallowed and won’t enter the lungs
• the hairs in our nose trap particles that may contain pathogens
• our stomach contains HCL acid that kills bacteria
• if we smell and taste food that is bad, we don’t eat it, as it may contain something

Question 8

What are the different ways we can prevent ourselves from catching these diseases?

Answer 8

• Good personal hygiene
• food hygiene:-
  At room temp(10 c to 48 c) bacteria can grow easily
  At 1 c bacteria is immediately killed or won’t work
  At temperatures above 68 c bacteria is killed
  At 120 C bacteria spores are instantly killed
• good water supply
• managing our waste supply

Question 9

What is cholera, and how is it caused?

Answer 9

Cholera is a serious transmissible disease caused by bacterium. It can spread if your food and water supply is contaminated with the feces of an infected person.

Question 10

What are the effects of cholera?

Answer 10

Cholera bacterium are ingested and multiply. The bacteria attached itself to the walls of the alimentary canal. The bacteria releases a toxin. The toxin produces an influx of Cl ions. The Cl ions accumulate in the lumen. This decreases the water potential in the lumen and if the water potential in the lumen is lesser than the water potential in the blood, water will flow into the lumen.
Thus death by dehydration could occur, and loss of Cl ions in the blood. To not die, a continuous water supply needs to be there, and eventually someone can recover.

Question 11

Describe what an antibody is and what an antigen is.

Answer 11

In your body you have thousands of different types of lymphocytes that produces a specific antibodies. These antibodies are complementary to the shape of a molecule] called an antigen.

An antigen is found on the surface of a pathogen. To destroy pathogen the antibody has to be perfectly complementary to the antigen.

Antigen: Is recognized as a foreign substance in the body- because its not part of the body’s original chemical substance. It, stimulates the production of antibodies.

Question 12

Do antibodies imeediatly kill pathogens or is there another process?
Do all lymphocytes produce an antibody when a pathogen enters a host?

Answer 12

The antibodies bind with the antigen, which sometimes kill them. But usually antibodies hold the pathogens together, so that they stop multiplying and moving around, this makes it easier for the phagocyte to kill them
Usually not all lympohcytes produce antibodies, as it would be a waste of energy and materials. Instead they wait for a signal that tells them to produce their specific antibody to combat the pathogen.

Question 13

How does a lymphocytes react to a pathogen.

Answer 13

1) The lymphocytes come in contact with the antigens of the pathogen
2) The lymphocyte that divides and forms inidvidual cells, so they can produce more antibodies
3) Lymphocytes secrete antibodies.
4) The antibodies binds itself to the antigen and destroy sthe pathgoen.

Question 14

Why do we fall ill?

Answer 14

This process takes time, as it takes time for the signal to arrive, the lymphocytes to produce identical cells, and then produce antibodies. And then takes time for the antibodies to kill the antigen. . Thus we get ill.

Question 15

How is the covid 19 virus transmitted?

Answer 15

Passed on in droplets(in moisture). Remain on surface, and can then get into respiratory system , if they touch the surface and then the mouth. Virus can be transmitted from a person who is asymptomatic, who are people whoa re completely unaware they have symptoms and are passing the virus. In most people the virus causes only mild symptoms. But in other the lungs can be so badly affected, that the person has difficulty with breathing.

Question 16

What is a vaccine?

Answer 16

In most countries, at a young age, children are given vaccines to immune their system, adults are also given if there is a serious disease.
Vaccine: A harmless preparation of dead or inactivated pathogens, that is injected in the body to provide an immune response. Some disease require two shots of vaccines, the first shot proceed partial protection, generating enough memory cells and antibodies for that. The second dose, ensures that all the memory cells and antibodies that are required are at hand.

Question 17

What is active immunity?

Answer 17

A long-term defense against a pathogen by antibody production in the body. WE can get it by, being infected or being vaccinated. The memory cells that were maid can spring up into action at an instant and make antibodies stop an invading pathogen.

Question 18

What is passive immunity?

Answer 18

Passive immunity: Short term defence against an antibody from another individual, such as froma mother to an infant.
Babies get passive immunity from mother’s antibodies in her body, useful a sbaby doesn’t have any defense mechanisms and is very weak. WE can also injext antiboides, or take tablets.

Question 19

What are memory cells?

Answer 19

A Long-lived cells produced by the division of lymphocytes that have contacted their antigen, memory cells are able to respond quickly to subsequent contact with the same antigen.