Immune System Quiz For 8th Grade

All of the factors mentioned in the options - toxic substances, poor nutrition, inheritance, and personal behavior - can contribute to causing diseases. Exposure to toxic substances can lead to various health problems, while poor nutrition weakens the immune system and makes individuals more susceptible to diseases. Inheritance refers to the genetic factors that can increase the risk of certain diseases. Personal behavior, such as smoking, excessive alcohol consumption, and lack of exercise, can also contribute to the development of diseases. Therefore, all of these factors can cause or contribute to the occurrence of diseases.

Leukocytes are commonly known as white blood cells. These cells are an essential part of the immune system and help to defend the body against infections and diseases. They are responsible for identifying and destroying harmful pathogens, such as bacteria, viruses, and fungi. Leukocytes are produced in the bone marrow and circulate throughout the body via the bloodstream. Their presence in the blood is crucial for maintaining a healthy immune response and overall well-being.

A person who has HIV/AIDS and a compromised immune system will not be able to fight infections. HIV attacks and weakens the immune system, specifically the CD4 cells that are responsible for fighting off infections. As a result, the person's immune system becomes compromised, making them more susceptible to various infections and diseases.

Vaccinations use weakened microbes (or parts of them) to stimulate the immune system to react. This statement is true because vaccines typically contain weakened or inactivated forms of the virus or bacteria that they protect against. These weakened microbes are introduced into the body, which triggers an immune response. The immune system recognizes the foreign substances and produces antibodies to fight against them. This process helps the body develop immunity to the specific pathogen, so that if the person is exposed to the actual disease-causing microbe in the future, their immune system is already prepared to defend against it.

Lymphocytes are a type of white blood cells that play a crucial role in the immune system. They are responsible for recognizing and attacking foreign substances in the body. In this case, the correct answer is "antigens" because lymphocytes recognize antigens as foreign molecules. Antigens are substances that can stimulate an immune response, such as those found on the surface of bacteria, viruses, or other pathogens. When lymphocytes detect antigens, they initiate an immune response to eliminate the foreign invaders.

Red blood cells have a lifespan of approximately 120 days. During this time, they play a crucial role in transporting oxygen from the lungs to the body's tissues and removing carbon dioxide. As they age, red blood cells become less flexible and more prone to being removed from circulation by the spleen. This lifespan is regulated by various factors, including the production of new red blood cells by the bone marrow. After their lifespan, old red blood cells are broken down and recycled by the body.

The release of chemicals known as histamines as a result of antibody production is best represented by the letter "Allergies". Allergies occur when the immune system overreacts to normally harmless substances, such as pollen or certain foods, and releases histamines as part of the immune response. These histamines cause symptoms such as sneezing, itching, and inflammation.

Antibiotics have been specifically developed by biological researchers to combat bacterial infections. These medications target and kill bacteria or inhibit their growth, helping to protect humans from bacterial diseases. Antibiotics are not effective against viral infections or cancer, which require different treatment approaches. Therefore, the correct answer is bacterial.

The diagram most likely represents the process of uncontrolled cell division, which is known to cause cancer. This is suggested by the fact that the other statements do not directly relate to the process of cell division causing cancer. The statement about cell division accelerating to maintain homeostasis is not supported by the diagram, while the statements about the immune system fighting a virus and the replacement of dead skin cells do not seem to be relevant to the diagram. Therefore, the best description for the diagram is that uncontrolled cell division causes cancer.

Viruses are composed of a core of genetic material, which can be either DNA or RNA. Unlike cells, viruses do not have their own cellular structure or organelles. They cannot replicate or carry out metabolic activities on their own and rely on host cells to reproduce. Therefore, the correct answer is that a virus is composed of a core of DNA or RNA.

The human body is capable of producing millions of different types of cytotoxic T cells. Cytotoxic T cells are a type of white blood cell that play a crucial role in the immune response by recognizing and destroying infected or cancerous cells. Each cytotoxic T cell has a unique receptor on its surface that allows it to recognize a specific antigen. This diversity in cytotoxic T cells ensures that the immune system can effectively respond to a wide range of pathogens and protect the body from various diseases.

When negative feedback mechanisms fail to maintain homeostasis, it can lead to an imbalance in the body's internal environment. This can result in the development of various diseases or health conditions. In the given scenario, the failure of negative feedback mechanisms to control blood pressure during exercise may lead to hypertension or other cardiovascular diseases. Therefore, the statement "may produce disease" accurately describes the potential consequences of the failure of negative feedback mechanisms in maintaining homeostasis.