HomeMock TestState PCSRailwaySSCHSSCDSSSBRO/AROUPSC

Human Anatomy and Physiology : V. Circulatory System Part-II

📆 October 28, 2024

Total Questions: 40

21. Which of the following helps us in protecting from infection – [R.A.S./R.T.S. (Pre) 1999]

Correct Answer: (b) W.B.C.
Solution:White blood corpuscles (WBCs) are disease-fighting cells found in blood. When our blood is infected by any harmful bacteria or virus at any place in the body, white blood corpuscles reaches there and eats up or destroys these harmful outsiders.

WBC - White blood cells are also called leukocytes or leucocytes. They are cells of the immune system, which is mainly responsible for:

  • Protecting and fighting against invading pathogens
  • Stimulates the production of the progesterone hormone
  • Play a vital role in the human reproductive system by producing a network of blood vessels within the ovary.

On an average, the total count of white blood cells in every microliter of blood ranges between 4 and 11 thousands and a healthy person will produce around 80 to 100 billions of white blood cells every day. The lifespan of white blood cells ranges between 13 and 20 days.

White blood cells are nucleotide blood cells which are white in color, hence they are called white blood cells. These blood cells are characterized into granulocytes and agranulocytes.

22. The main function of white blood cells is – [Jharkhand P.C.S. (Pre) 2003]

Correct Answer: (c) To develop resistance towards disease
Solution:White blood corpuscles (WBCs) are disease-fighting cells found in blood. When our blood is infected by any harmful bacteria or virus at any place in the body, white blood corpuscles reaches there and eats up or destroys these harmful outsiders.

WBC - White blood cells are also called leukocytes or leucocytes. They are cells of the immune system, which is mainly responsible for:

  • Protecting and fighting against invading pathogens
  • Stimulates the production of the progesterone hormone
  • Play a vital role in the human reproductive system by producing a network of blood vessels within the ovary.

On an average, the total count of white blood cells in every microliter of blood ranges between 4 and 11 thousands and a healthy person will produce around 80 to 100 billions of white blood cells every day. The lifespan of white blood cells ranges between 13 and 20 days.

White blood cells are nucleotide blood cells which are white in color, hence they are called white blood cells. These blood cells are characterized into granulocytes and agranulocytes.

23. Antibodies are formed in blood plasma by which of the following – [Jharkhand P.C.S. (Pre) 2003]

Correct Answer: (b) Lymphocytes
Solution:Lymphocytes produce antibodies in blood plasma and are responsible for inactivating poisonous substances. Lymphocytes are very small white blood cells with large nucleus wanders in the whole body and their number is large in total W.B.C. count (about 20-25%). Like an army, lymphocytes protect the body by co-ordinating with all parts of the immune system. Lymphocytes include natural killer cells, T cells and B cells which are the major cellular components of the immune response.

24. The immunity (defence) is mostly related with - [R.A.S./R.T.S. (Pre) 1993]

Correct Answer: (a) Lymphocytes
Solution:Lymphocytes produce antibodies in blood plasma and are responsible for inactivating poisonous substances. Lymphocytes are very small white blood cells with large nucleus wanders in the whole body and their number is large in total W.B.C. count (about 20-25%). Like an army, lymphocytes protect the body by co-ordinating with all parts of the immune system. Lymphocytes include natural killer cells, T cells and B cells which are the major cellular components of the immune response.

25. The most important cell type associated with the immunity of the body is : [68th B.P.S.C. (Pre) 2022]

Correct Answer: (c) lymphocytes
Solution:Lymphocytes produce antibodies in blood plasma and are responsible for inactivating poisonous substances. Lymphocytes are very small white blood cells with large nucleus wanders in the whole body and their number is large in total W.B.C. count (about 20-25%). Like an army, lymphocytes protect the body by co-ordinating with all parts of the immune system. Lymphocytes include natural killer cells, T cells and B cells which are the major cellular components of the immune response.

26. Which one of the following statements best describes the role of B cells and T cells in the human body? [I.A.S. (Pre) 2022]

Correct Answer: (d) They protect the body from the diseases caused by pathogens.
Solution:

The B and T lymphocytes (B and T Cells) protect the human body from the diseases caused by the pathogens. T cells and B cells are the most critical components of the adaptive immune system. These cells are essential for fighting disease and play an important role in regulating hypersensitivity to harmless or ‘self’ antigens. T cells recognize viral antigens outside the infected cells, whereas B cells can recognize the surface antigens of bacteria and viruses directly. They are involved in the acquired or antigen-specific immune response given that they are the only cells in the organism able to recognize and respond specifically to each antigenic epitope. The B Cells have the ability to transform into plasmocytes and are responsible for producing antibodies (Abs). Thus, T cells are involved in cell-mediated immunity, whereas B cells are primarily responsible for humoral immunity (related to antibody production in body fluids).

27. The viscous nature of human blood is due to – [Jharkhand P.C.S. (Pre) 2013]

Correct Answer: (d) All of the above
Solution:The primary determinants of blood viscosity are hematocrit and plasma viscosity. Plasma’s viscosity is determined by water-content and macromolecular components, so these factors that affect blood viscosity are the plasma protein concentration and types of proteins in the plasma.

Blood transports substances like digested food from the small intestine to the other parts of the body. It carries oxygen from the lungs to the cells of the body. It also transports waste for removal from the body. Blood is a liquid, which has cells of various kinds suspended in it. The fluid part of the blood is called plasma. One type of cells are the red blood cells (RBC) which contain a red pigment called haemoglobin.

Haemoglobin bind with oxygen and transports it to all the parts of the body and ultimately to all the cells. The presence of haemoglobin makes blood appear red. The blood also has white blood cells (WBC) which fight against germs that may enter our body. The clot is formed because of the presence of another type of cells in the blood, called platelets.

28. The diameter of white blood corpuscles in human body is, about : [Chhattisgarh P.C.S. (Pre) 2008]

Correct Answer: (a) 0.007 mm
Solution:

The number of leukocytes (WBCs) in the blood is often an indicator of disease. The normal white blood cell count is about 4,000–11,000 per micro litre of blood. They make up approximately 1% of the total blood volume in a healthy adult. An increase in the number of leukocytes over the upper limits is called leukocytosis, and a decrease below the lower limit is called leukopenia. The diameter of W.B.C. in human body is about 0.007 mm.

29. In pathology excess of white corpuscles in the blood is called – [Uttarakhand P.C.S. (Pre) 2007]

Correct Answer: (b) Leukemia
Solution:

Leukemia is a group of cancer that usually begins in the bone marrow and results in high numbers of abnormal white blood cells. These white blood cells are not fully developed and are called blasts or leukemia cells. Symptoms may include bleeding and bruising problems.

30. In which part of our body are formed Red Blood Cells? [Uttarakhand Lower Sub. (Pre) 2010, Uttarakhand U.D.A./L.D.A. (mains) 2006]

Correct Answer: (d) Bone Marrow
Solution:Erythropoiesis is the development process by which new erythrocytes or Red Blood Cells are produced; it lasts about 7 days. Through this process, erythrocytes are continuously produced in the red bone marrow of large bones at a rate of about 2 million per second in a healthy adult (In the embryo, the liver is the main site of red blood cell production). The production can be stimulated by the hormone erythropoietin (EPO), synthesized by the kidney. Just before and after leaving the bone marrow, the developing cells are known as reticulocytes; these comprise about 1% of circulating red blood cells.
Home  | Mock Test  | State PCS  | Railway  | SSC  | HSSC  | DSSSB  | RO/ARO  | UPSC  | 
© 2024 Mock Test 365 | All Rights Reserved