Biology · Science General

Disease Causative Agents

2,531 Questions

Disease causative agents questions test your understanding of viral, bacterial, and fungal infections, along with their transmission methods. These are common topics in general science sections of SSC and railways exams. Practice these questions to accurately identify disease pathogens and symptoms.

Viral diseasesFoodborne illnessesDisease transmission methodsExtrinsic disease factorsCommon pathogens

Disease Causative Agents Questions

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

Which of these diseases are transmitted through body fluids ?

  1. AIDS and hepatitis-B

  2. Malaria and typhoid

  3. Influenza and cholera

  4. Cholera and rabies
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

AIDS and hepatitis-B are sexually transmitted diseases that are spread by contact with infected body fluids which include blood, semen, vaginal fluid or other body fluids through the mucous. Thus the correct answer is option A.

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

Which of the following diseases spread through infected needles or by blood transfusion?

  1. Measles

  2. Mumps

  3. AIDS

  4. Kalazar
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

AIDS (Acquired immunodeficiency syndrome) is an infection which is caused by Human immunodeficiency virus (HIV). The causative agent of the disease is a virus and so the disease can spread from one person to the other by sexual contact. The disease also spreads through the use of the infected needles, syringes and blood transfusion from the infected person.

Thus, the correct answer is option C. 

Multiple choice biology world of microbes cancer and aids hiv and aids immunity related disorders and problems

Among the following, most dangerous STD is caused by

  1. Treponema pallidum

  2. Human immunodeficiency virus

  3. Neisseria gonorrhoeae

  4. Hepatitis B virus
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

STD are sexually transmitted diseases that are transmitted through sexual contact. Treponema pallidum is a bacterium that causes syphilis disease. Human immunodeficiency virus (HIV) causes AIDS. Neisseria gonorrhoeae is a bacterium that causes Gonorrhea disease. Hepatitis B virus causes hepatitis disease. Out of these diseases, Syphilis is very difficult to diagnose. Hence, this makes it the most dangerous STD.

Thus, the correct answer is 'Treponema pallidum.'

Multiple choice biology world of microbes cancer and aids hiv and aids immunity related disorders and problems

Gonorrhoea is caused by

  1. Bacteria

  2. Virus

  3. Fungi

  4. Protozoa
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sexually transmitted diseases also called venereal diseases, are spread by sexual intercourse with an infected person. The major venereal diseases are syphilis and gonorrhea. Gonorrhoea is caused by a diplococcus bacterium, Neisseria gonorrhoeae. The victim feels burning sensation and pain during urination. Thus option A is the correct answer.

Multiple choice biology world of microbes cancer and aids hiv and aids immunity related disorders and problems

Which of the following is STD?

  1. Cancer

  2. Malaria

  3. Pneumonia

  4. Trichomoniasis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Trichomoniasis is a sexually transmitted disease. It is caused by Trichomonas vaginalis.
Malaria is caused by Plasmodium sp and pneumonia by Diplococcus pneumonia. 

Cancer is caused by mutated DNA in the body cells.
Thus, the correct answer is (D).

Multiple choice biology world of microbes cancer and aids hiv and aids immunity related disorders and problems

Which one of the following statements is correct regarding sexually transmitted diseases (STDs)?

  1. A person may contact syphilis by sharing milk with one already suffering from the disease.

  2. Haemophilia is one of the STDs.

  3. Genital herpes and sickle-cell anaemia are both STDs.

  4. The chances of a 5-years boy contracting a STD are very rare.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Syphilis is caused by bacterium Treponema pallidum. It is a sexually transmitted disease (STD) which is transmitted through sexual intercourse with infected person. Haemophilia is an X-linked genetic disorder of blood, It is not transmitted via any sexual practice. Genital herpes is an STD while sickle-cell anaemia is an autosomal hereditary disorder. The chances of a 5 years old boy contacting an STD are very rare since he is unlikely to have sex at this age. So, the correct answer is 'The chances of a 5-years boy contracting a STD are very rare'.

Multiple choice

What is the delivery mechanism for subcutaneous anthrax?

  1. Blood contact

  2. Simple dispersal device

  3. Direct contact

  4. Water contamination
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Subcutaneous anthrax occurs when the bacteria enter through a cut or abrasion on the skin, which is classified as direct contact.

Multiple choice

What type of transmission occurs with Hepatitis C

  1. Foodborne transmission

  2. Direct contact transmission

  3. Airborne Transmission

  4. Vector-borne transmission
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hepatitis C is primarily transmitted through direct contact with infected blood, such as through shared needles or medical procedures.

Multiple choice

What is a leading cause of communicable disease deaths annually?

  1. Malaria

  2. Viral hepatitis

  3. STDs

  4. Salmonellosis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Malaria is a leading cause of death among communicable diseases globally, particularly in tropical regions. While the other options are significant health concerns, they do not match the scale of annual mortality associated with malaria.

Multiple choice

Which disease is an airborne illness?

  1. Malaria

  2. Lyme Disease

  3. Measles

  4. Norovirus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Measles is a highly contagious viral disease that spreads through respiratory droplets in the air. Malaria is vector-borne, Lyme is tick-borne, and Norovirus is typically fecal-oral.

Multiple choice biology health and diseases non-infectious diseases non infectious diseases categories of diseases

Cancer is not a contagious disease instead, it is an error in cellular regulation.
Why is it that cancer can spread so quickly throughout a living organism?

  1. Some cancer cells can produce their own growth factor to pass cell cycle checkpoints.

  2. Cancer cells reproduce by going through the phases of the cell cycle in the wrong sequence.

  3. Cancer cells are developed by natural selection due to overuse of antibiotics.
  4. Cancer cells spend most of their time in the G$ _0$ phase of the cell cycle.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cell cycles are regulated by cyclins and Cyclin dependent kinases (CDK). In cancer cells this regulatory mechanism is lost, thus the cells divide or proliferate in an uncontrolled manner after a certain stage, they produce growth factors and respond to them in an autocrine manner. Since, they are the body cells they are not destroyed by the immune system. They are capable of separating from the parent tumor and establishing else where in the body, a process called metastasis.

So, the correct answer is 'Some cancer cells can produce their own growth factor to pass cell cycle checkpoints'

Multiple choice biology health and diseases non-infectious diseases non infectious diseases categories of diseases

Cervical cancer is caused by 

  1. Chlamydia

  2. Human Papillomavirus

  3. Herpes Simplex Virus

  4. Neisseria gonorrhoeae
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Cervical cancer is cancer arising from the cervix. It is due to the abnormal growth of cells that have the ability to invade or spread to other parts of the body. It is caused by Human Papillomavirus
  • Initially, no symptoms are seen. Later symptoms may include abnormal vaginal bleeding, pelvic pain, or pain during sexual intercourse.
  • Hence Cervical cancer is caused by Human Papillomavirus.
  • So, the correct answer is 'Human Papillomavirus'.