CBSE Questions for Class 12 Medical Biology Human Health And Disease Quiz 1 - MCQExams.com

Psoriasis, Vitiligo and Rheumatoid arthritis are autoimmune diseases. An illness that occurs when the body tissues are attacked by its own immune system is known as autoimmune disease. Alzheimer's is caused by brain cell death. It is a neurodegenerative disease. There is progressive brain cell death that happens over time. Thus the correct answer is option A.

• HIV is a member of viruses called retroviruses. 
• It contains ssRNA when it infects the host cell ssRNA. 
• It is transcribed into cDNA and integrates into the DNA of the host cell.

• Interferon is a group of proteins that increases the resistance of cells to viral infection
• Interferon also acts as cytokines and are involved in the generation of the immune responses.
• Three types of interferons have so far been discovered, alpha, beta, and gamma, all of which have immune-modulating effects.
• Interferons are used in the treatment of cancer and autoimmune diseases.

• Ringworm is actually a skin infection caused by fungus. No worms involved. The name “ringworm” probably comes from the rash that many people see. On the skin, the rash often has a ring-shaped pattern and a raised, scaly border that snakes its way around the edge like a worm. Ringworm is common.
• Cholera is an infectious disease that causes severe watery diarrhoea, which can lead to dehydration and even death if untreated. It is caused by eating food or drinking water contaminated with a bacterium called Vibrio cholerae.
• Typhoid fever, also known simply as typhoid, is a bacterial infection due to a specific type of Salmonella that causes symptoms.
• Plague is a disease that affects humans and other mammals. It is caused by the bacterium, Yersinia pestis. Humans usually get plague after being bitten by a rodent flea that is carrying the plague bacterium or by handling an animal infected with the plague.

• An autoimmune disease is a condition arising from an abnormal immune response to a normal body part. 
• In autoimmune diseases, the immune system mistakenly attacks the body tissues leading to the destruction of body tissue. 
• The immune system recognizes the body tissue as foreign and produces antibodies against the body tissue.

• Acquired Immunodeficiency syndrome(AIDS) is caused by a retrovirus called human immunodeficiency viruses(HIV).
• People transmit HIV in bodily fluids, including, blood, semen, vaginal secretions. anal fluids, breast milk.
  
• When an injectable used for AIDS patient is used for the normal individual the HIV virus gets transmitted through blood. Hence The disease caused by the injectable drug is AIDS.
• So, the correct answer is 'AIDS'.

• People use drugs for many reasons: they want to feel good, stop feeling bad by masking the emotions, or perform better in school or at work, or forget about problems for a time being, or they are curious because others are doing it and they want to fit in. The last reason is very common among teens. 
• Hence, People take drugs to Mask the emotions and Forget about the problems for a time being.
•  So, the correct answer is 'Both A and B'.

• Allergies, also known as allergic diseases are a number of conditions caused by hypersensitivity (excessive) of the immune system to typically harmless substances in the environment. 
• Symptoms may include red eyes, an itchy rash, sneezing, a runny nose, shortness of breath. Food, insect stings, and medications are common causes of severe reactions.

• Enterobius vermicularis belong to the phylum Aschelminthes (roundworm) and is called pinworm as it is a tiny and narrow worm, also known as threadworm or seatworm. They're white in color and less than a half-inch long.
• Schistosoma haematobium is commonly called a blood fluke and belongs to the phylum Platyhelminthes.
• Wuchereria bancrofti is a thread-like filarial nematode. 
• Ancylostoma duodenale is also a nematode and is commonly called an old-world hookworm. 

• Animals of the phylum Nemathelminthes are characterized by the presence of pseudocoelom. Such a coelom does not arise from the mesoderm and is not lined by the peritoneum.
  
• Enterocoelom is a true coelom that arises by pinching of mesodermally lined pouches. 
• Haemocoel term is used to describe the body cavity of arthropods and molluscs. Blood flows within this cavity and bathes the internal organs of the body.

• The animals in the phylum Aschelminthes have a false body cavity also called pseudocoelom. 
• These animals possess a digestive canal with two openings at the end, i.e. mouth at the anterior end and anus at the posterior end. 
• A digestive canal is present in the body cavity and hence, it is called a 'tube within a tube' body plan. 
• Poriferans show cell aggregate plan while Coelenterates and Platyhelminthes show a blind sac body plan.