1) the immune system is designed to defend against bacteria, microbes, viruses, toxins, and what?
a) parasites
b) cuts
c) fever
d) algae
2) when something dies, the immune system continues to operate.
true
false
3) when you get a cut, what enters the body?
4) what is a result of the immune system doing its job on an infected cut?
a) scab
b) pus
c) bleeding
d) itching
5) allergies are an overreaction of the immune system.
true
false
6) lack of what vitamin causes rickets?
a) c
b) a
c) d
d) e
7) swollen and bleeding gums, swollen joints and bruising are signs of what?
a) rickets
b) cancer
c) glaucoma
d) scurvy
8) if you do not get enough iron you get anemia.
true
false
9) when the liver is damaged from alcoholism, it is called:
a) cirrhosis
b) scurvy
c) anemia
d) rickets
10) what condition is spotted by melanoma?
a) scurvy
b) rickets
c) cancer
d) anemia
11) polio causes paralysis by attacking what?
a) bones
b) nerve cells
c) blood cells
d) spinal fluid
'
12) list the 3 ways your body protects from infections.

1) A. Parasites.
The immune system is designed to defend our body from against 'invaders' that it does not recognize and which might be potentially harmful to our health and well-being. It is essential for our survival. It works through various systems and types of cells.

2) True.
When the immune system kills the foreign body that has entered our system, the specific cells that work on it do not necessarly continues living, but the whole system continued working, searching for other 'intruders' that might cause harm to our health. 

3) When you get a cut, that might be from paper or a knife, or whatever source, there are germs entering your body. The immune system acts upon it right away, starting a 'war' against the unwanted bodies. Then, our body is designed to fix itself, activating the tissues and closing the cut, to prevent us to continue bleeding and further germs to enter our system.

4) B. Pus
Our immune system is designed to keep the wounds from getting infected, that is why a scab is created right away. But when the wound does get infected, you might see some sort of liquid coming out of it: that is the pus, which is non-other than protein-rich fluid of dead leukocytes or white cells, that have died while killing the infection. 

5) True. 
Having an allergy means that your body identifies as harmful some non-harmful substances, such as: dust, pollen, cat hair, etc. When in contact with this substances, the immune system overreacts in order to protect you from them. The reactions have different degrees of intencity, it may be sneezing and dizziess, or it might get intense such as anaphylactic shocks, which are potentially life-threatening. 

6) C. Lack of Vitamin D. 
A vitamin D deficiency is one of the most common causes for Rickets. 
Rickets is a disease that causes the bones to soften, and it is generally encountered in children. This is why it is very important to include a good amount of vitamin D in the infant's diet, as prevention to this condition. 

7) D. Scurvy.
Scurvy is a disease cause by a deficency of vitamin C. 
This disease if often associated with sailors from the 15th to the 18th century, as many have died from the consequences of the untreated symptoms, which are: swollen and bleeding gums, limbs weakness, anemia, and skin problems. 

8) True.
Iron deficiency anemia is the most common type of anemia. It indicated the extreamly low level of hemoglobin (they are responsible for carrying around oxygen) in the red blood cells. Iron is needed in order to create red blood cells, so a lack of iron will, most likely, cause you to have anemia. 

9) A. Cirrhosis.
Cirrhosis is when the liver is scarred by different causes, one of them in alcoholism. It is how the liver responds to damage: everytime it gets damaged, it has the ability to repair itself, leaving behind scars. Thus, when there are too many, the condition is called Cirrohsis, and there is nothing that can be done to repair it. 

10) C. Cancer.
Melanoma skin cancer can be detected by spots on your skin. Moles, lumps, markings, they should all be kept under control. If there are any changes, or anomalies, it could be a sign of skin cancer. Obviously not all melanomas will lead to cancer, but a check every now and then is always reccomended.

11) D. Spinal Fluid. 
Polio is an infectious disease that may reach the spinal cord and the brain, causing paralysis and death. It hit the nervous system, affecting the areas responsible for our movements. The symptoms are neck and back stiffness, unfusual reflexes and having trouble breathing. 

12) 
Skin and Mucous membranes - The skin itself is a barrier against infections. Mucous can be found in our nose, throat, urethra.
Immune system and blood cells - they are the ones who fight infections when encountered in our bodies, making sure that the foreign entities are killed before they could result too harmful for our health.
Acid - our stomach and an few other organs contain/produce acid that can melt unwanted infections.