Blood and Blood Group Questions in English

(D) Statement $a$ in option $D$: $RBC$s (erythrocytes) are formed in the red bone marrow in adults.
Statement $b$ in option $D$: Globulins are plasma proteins that primarily act as antibodies (immunoglobulins) and are involved in the defense mechanism of the body.
Other options are incorrect because:
- Plasma contains $90-92\%$ water,but lymph is a colourless fluid,not green.
- Proteins contribute $6-8\%$ of plasma,but lymph is not formed in the red bone marrow; it is formed from interstitial fluid.
- Fibrinogen is required for blood clotting,not albumin (which maintains osmotic pressure).

(B) Blood plasma contains three major proteins: Albumins,Globulins,and Fibrinogens.
$1$. Albumins are primarily responsible for osmotic balance in the blood.
$2$. Globulins are primarily involved in defense mechanisms of the body,providing immunity.
$3$. Fibrinogens are needed for clotting or coagulation of blood.
Therefore,the pair 'Globulin = immunity' is the only correct statement.

(B) Leucocytes (White Blood Cells) are colourless due to the lack of haemoglobin $(Hb)$.
They are nucleated and are relatively lesser in number compared to erythrocytes.
The average count of leucocytes is $6000-8000 \, mm^{-3}$ of blood,not $5000-8000 \, mm^{-3}$.
Leucocytes are generally short-lived cells.
Therefore,the statement in option $B$ is incorrect.

(B) Assertion $(A)$ is incorrect because globulins are primarily involved in defense mechanisms of the body (as antibodies),while albumins are involved in osmotic balance.
Reason $(R)$ is incorrect because the clotting factors present in the blood are in an inactive form (proenzymes) to prevent unnecessary clotting within the vessels.
Therefore,both statements are incorrect.

(A) The $WBC$s that act as phagocytes are Neutrophils and Monocytes.
Among the given options,Neutrophils are the most abundant phagocytic cells,comprising $60-65\%$ of the total $WBC$ count.
They are the primary cells that destroy foreign organisms entering the body.
Monocytes also act as phagocytes,but they represent a smaller percentage $(6-8\%)$.
Therefore,based on the provided options,the correct answer is the one representing Neutrophils.

(D) Individuals with $AB$ blood group possess both $A$ and $B$ antigens on the surface of their red blood cells.
Because they have both antigens,their immune system recognizes both $A$ and $B$ as 'self'.
Therefore,they do not produce anti-$A$ or anti-$B$ antibodies in their blood plasma.
This makes them universal recipients,meaning they can receive blood from individuals with $AB, A, B,$ and $O$ blood groups.
Thus,the correct answer is $AB, A, B, O$ and nil.

(D) Thrombocytes,also known as blood platelets,are cell fragments produced from megakaryocytes in the bone marrow.
They play a crucial role in the process of blood coagulation or clotting.
When a blood vessel is injured,thrombocytes aggregate at the site of the injury and release substances that trigger the clotting cascade.
$A$ significant reduction in the number of thrombocytes (thrombocytopenia) impairs the body's ability to form clots,which can lead to excessive bleeding or hemorrhage from the body.

(B) Blood coagulation factors are present in the plasma in an inactive state to prevent unnecessary clotting within the blood vessels.
When blood clots,the clotting factors (like fibrinogen) are consumed,and the remaining fluid is known as serum.
Therefore,the correct sequence is inactive form and serum.

(D) Let's analyze each statement:
$(I)$ $RBCs$ (Red Blood Cells) are formed in the red bone marrow,not white bone marrow,in adults. Thus,statement $(I)$ is incorrect.
$(II)$ $RBCs$ appear red due to the presence of the iron-containing respiratory pigment called haemoglobin. This statement is correct.
$(III)$ In most mammals,mature $RBCs$ are devoid of a nucleus (enucleated) to provide more space for haemoglobin. Thus,statement $(III)$ is incorrect.
$(IV)$ $A$ healthy individual has $12-16 \, g$ of haemoglobin in every $100 \, ml$ of blood,not $1000 \, ml$. Thus,statement $(IV)$ is incorrect.
Therefore,statements $(I), (III),$ and $(IV)$ are incorrect.

(C) Individuals with blood group $O$ lack both $A$ and $B$ antigens on the surface of their red blood cells,which prevents an immune reaction when donated to individuals of other blood groups. Therefore,they are called 'universal donors'.
Individuals with blood group $AB$ possess both $A$ and $B$ antigens on their red blood cells and lack both anti-$A$ and anti-$B$ antibodies in their plasma. This allows them to receive blood from any other blood group without an immune reaction. Therefore,they are called 'universal acceptors'.

(A) The process of blood coagulation involves a cascade of enzymatic reactions.
Inactive fibrinogens present in the plasma are converted into active fibrin threads by the enzyme $Thrombin$.
$Thrombin$ itself is formed from inactive $Prothrombin$ present in the plasma by the action of the enzyme complex $Thrombokinase$ (also known as Factor $X$ or Stuart-Prower factor).
Therefore,the specific enzyme responsible for the conversion of fibrinogen to fibrin is $Thrombin$.

(B) The blood of vertebrates contains hemoglobin,which is a respiratory pigment present in red blood cells $(RBCs)$.
Hemoglobin is a conjugated protein consisting of a protein part called globin and a non-protein prosthetic group called heme.
The heme group contains an iron $(Fe^{2+})$ ion at its center,which is responsible for binding with oxygen molecules.
Therefore,iron is the essential mineral element found in the blood of vertebrates.

(D) Antibodies are specialized proteins produced by the immune system to identify and neutralize foreign pathogens like bacteria and viruses.
In the human body,$B$-lymphocytes are the specific type of white blood cells responsible for the production of antibodies.
When these cells encounter an antigen,they differentiate into plasma cells,which secrete large quantities of antibodies into the blood and lymph.
Therefore,the correct answer is $D$ (Lymphocytes).

(A) Vitamin $K$ is essential for the synthesis of clotting factors in the liver,specifically prothrombin (Factor $II$),Factor $VII$,Factor $IX$,and Factor $X$. Prothrombin is an inactive precursor protein that is synthesized in the liver in the presence of Vitamin $K$. Once synthesized,it is released into the blood,where it later participates in the coagulation cascade to be converted into thrombin. Therefore,the primary role of Vitamin $K$ is in the synthesis of prothrombin.

(B) Coagulation or clotting of blood is a process that requires clotting factors,specifically fibrinogen,which is present in whole blood and lymph.
$A$. Blood plasma contains fibrinogen and will coagulate if clotting factors are activated.
$B$. Serum is the fluid remaining after blood has clotted; it lacks fibrinogen and other clotting factors,therefore it cannot coagulate.
$C$. Lymph (from the thoracic duct) contains clotting factors and can coagulate,although it does so more slowly than blood.
$D$. Whole blood contains all clotting factors,including fibrinogen,and will coagulate upon exposure to air or damaged surfaces.

(B) Basophils are a type of granulocyte white blood cell that play a crucial role in inflammatory responses.
They contain cytoplasmic granules that store chemical mediators.
Upon activation,basophils release histamine (which causes vasodilation and increases vascular permeability) and heparin (an anticoagulant that prevents blood clotting).
Therefore,the correct option is $B$.

(D) White blood cells $(WBCs)$ or leukocytes are the cells of the immune system that protect the body against infectious diseases and foreign invaders.
Among the various types of $WBCs$, Neutrophils and Monocytes are the most active phagocytic cells.
Neutrophils are the most abundant $WBCs$ $(60-65\%)$ and act as the first line of defense by engulfing bacteria.
Monocytes are the largest $WBCs$ and differentiate into macrophages in tissues, which are highly efficient at phagocytosis.
Therefore, the correct option is $D$.

(A) The blood group $O$ is determined by the genotype $ii$.
For a child to have blood group $O$ $(ii)$,both parents must contribute an $i$ allele.
Parents with blood group $AB$ have the genotype $I^A I^B$.
Since they do not possess the $i$ allele,they cannot produce a child with blood group $O$ $(ii)$.
Therefore,parents with blood group $AB$ cannot have a child with blood group $O$.

(C) Erythrocytes (Red Blood Cells) require specific factors for their maturation in the bone marrow.
Vitamin $- B_{12}$ (Cyanocobalamin) and Folic acid are essential for $DNA$ synthesis and the maturation of red blood cells.
$A$ deficiency of Vitamin $- B_{12}$ leads to pernicious anemia,where the red blood cells are immature and large (megaloblastic).
Therefore,Vitamin $- B_{12}$ is a critical factor for the maturation of erythrocytes.

(D) The transport of respiratory gases is primarily carried out by $R.B.C.$ and blood plasma.
$1.$ $R.B.C.$ (Red Blood Cells) contain hemoglobin, which binds with $O_2$ to form oxyhemoglobin and also carries a portion of $CO_2$ as carbaminohemoglobin.
$2.$ Blood plasma transports $O_2$ in a dissolved state (about $3\%$) and $CO_2$ in dissolved form (about $7\%$) as well as in the form of bicarbonates (about $70\%$).
$3.$ $W.B.C.$ (White Blood Cells) are primarily involved in the immune response and do not play a significant role in the transport of respiratory gases.
Therefore, both $R.B.C.$ and plasma are responsible for the transport of $O_2$ and $CO_2$.

(A) When red blood cells reach the end of their lifespan (approximately $120$ days),they are broken down in the spleen,liver,and bone marrow. The hemoglobin molecule is degraded into globin chains and heme. The heme group is further broken down into iron and biliverdin. Biliverdin is then rapidly converted into bilirubin,which is the primary pigment excreted by the liver into the bile. Therefore,bilirubin is the final major product of hemoglobin degradation.

(B) Erythroblastosis fetalis occurs when an $Rh^{-ve}$ mother carries an $Rh^{+ve}$ fetus.
During the first pregnancy,the mother's blood is exposed to the $Rh$ antigens of the fetus during delivery,causing her body to produce anti-$Rh$ antibodies.
In subsequent pregnancies,if the fetus is again $Rh^{+ve}$,these maternal antibodies can cross the placenta and destroy the fetal red blood cells,leading to severe anemia or jaundice.
Therefore,this condition is observed in marriages between an $Rh^{+ve}$ male and an $Rh^{-ve}$ female.

(C) person with blood group $A$ has $A$ antigens on the surface of their red blood cells and anti-$B$ antibodies in their plasma.
To avoid an immune reaction,the donor's blood must not contain $B$ antigens.
Therefore,a person with blood group $A$ can receive blood from individuals with blood group $A$ (same type) or blood group $O$ (universal donor,as it lacks both $A$ and $B$ antigens).
Thus,the correct option is $C$.

(B) Calcium ions $(Ca^{2+})$ play a critical role in the blood clotting process. They are essential for the activation of clotting factors,specifically in the conversion of prothrombin to thrombin. When calcium is removed from freshly collected blood (e.g.,by adding chelating agents like $EDTA$ or sodium citrate),the coagulation cascade is interrupted,thereby preventing the blood from clotting.

(B) The bone marrow is the primary lymphoid organ where all blood cells,including $RBCs$ (erythrocytes),$WBCs$ (leukocytes),and platelets,are produced through the process of hematopoiesis. Therefore,the bone marrow produces both $RBCs$ and $WBCs$.

(B) Antigens are specific proteins or carbohydrates present on the surface of red blood cells $(RBCs)$.
These antigens determine the blood group of an individual.
For example, in the $ABO$ blood grouping system, the presence of antigen $A$ or $B$ on the surface of $RBCs$ defines the blood type.
Therefore, antigens are found on the surface of the cell.

(A) White blood cells (leukocytes) have a relatively short lifespan compared to red blood cells. While the lifespan varies depending on the specific type of leukocyte (e.g.,neutrophils live for a few days,while some lymphocytes can live for years),the general lifespan for most circulating white blood cells is considered to be less than $10$ days. Therefore,the most appropriate option is $A$.

(A) White blood cells $(WBCs)$ are classified into two main categories based on the presence or absence of granules in their cytoplasm: granulocytes and agranulocytes.
$1$. Granulocytes contain granules in their cytoplasm and include neutrophils,eosinophils (acidophils),and basophils.
$2$. Agranulocytes lack distinct granules in their cytoplasm and include lymphocytes and monocytes.
Therefore,lymphocytes are agranulocytes.

(B) Blood plasma contains various electrolytes,including sodium,potassium,calcium,magnesium,chloride,bicarbonate,and phosphate ions.
Among these,$Na^+$ (sodium) is the most abundant cation in the blood plasma,playing a crucial role in maintaining osmotic pressure and fluid balance in the body.
Therefore,the correct option is $B$.

(A) White blood cells $(WBCs)$,also known as leukocytes,are nucleated cells.
They exhibit a property called diapedesis,which allows them to squeeze through the walls of blood capillaries to reach the site of infection or injury.
Option $B$ is incorrect because $WBCs$ possess a nucleus.
Option $C$ is incorrect because an increase in $WBC$ count (leukocytosis) is often associated with infections or leukemia (blood cancer),not a decrease.
Option $D$ is incorrect because $WBCs$ are produced in the bone marrow,although some lymphocytes mature in the thymus.

(A) In the $ABO$ blood grouping system,blood group '$O$' is characterized by the absence of both '$A$' and '$B$' antigens on the surface of red blood cells $(RBCs)$.
However,the plasma of individuals with blood group '$O$' contains both anti-$A$ (antibody '$a$') and anti-$B$ (antibody '$b$') antibodies.
Therefore,the correct statement is that there is an absence of antigens but a presence of '$a$' and '$b$' antibodies.

(C) Vitamin $- K$ is essential for the synthesis of clotting factors in the liver,such as prothrombin and factors $VII$,$IX$,and $X$.
When there is a deficiency of Vitamin $- K$,the blood clotting mechanism is impaired.
Consequently,the blood fails to clot effectively at the site of an injury,leading to continuous or prolonged bleeding.

(A) To separate blood into plasma and blood cells,the blood must be kept in a liquid state (prevented from clotting).
$1$. Heparin and sodium oxalate are anticoagulants that prevent blood clotting by removing or chelating calcium ions,which are essential for the coagulation cascade.
$2$. $A$ sterile test tube is standard for collection.
$3$. Calcium carbonate is a source of calcium ions. Adding calcium to blood promotes the coagulation process,which would cause the blood to clot,making it impossible to separate plasma and cells effectively. Therefore,a test tube containing calcium carbonate should not be used.

(C) In the $ABO$ blood grouping system,the presence of antigens on the surface of red blood cells determines the blood group.
$1$. Individuals with blood group $A$ have antigen $A$ and antibody $b$ in their plasma.
$2$. Individuals with blood group $B$ have antigen $B$ and antibody $a$ in their plasma.
$3$. Individuals with blood group $AB$ have both antigens $A$ and $B$ on their red blood cells but do not have any antibodies ($a$ or $b$) in their plasma.
$4$. Individuals with blood group $O$ do not have any antigens on their red blood cells but have both antibodies $a$ and $b$ in their plasma.
Therefore,the blood group with both antigens present and no antibodies is $AB$.

(D) Blood clotting (coagulation) is a complex process involving a cascade of clotting factors.
$Thromboplastin$ is a lipoprotein released by injured tissues or platelets that initiates the extrinsic pathway of blood coagulation.
When $Thromboplastin$ is introduced into the bloodstream,it acts as a catalyst for the conversion of prothrombin to thrombin,which subsequently converts fibrinogen into fibrin,leading to the formation of a blood clot at the site of introduction.
$Fibrinogen$ and $Prothrombin$ are inactive precursors already present in the blood,while $Heparin$ is an anticoagulant that prevents clotting.

(A) The presence of large,immature,nucleated,and hemoglobin-deficient erythrocytes (megaloblasts) is characteristic of megaloblastic anemia.
This condition is primarily caused by a deficiency of $Vitamin B_{12}$ (Cobalamin) and Folic acid $(Vitamin B_9)$.
These vitamins are essential for $DNA$ synthesis and the maturation of red blood cells in the bone marrow.
Deficiency leads to the failure of erythrocytes to mature,resulting in the release of immature,large cells into the bloodstream.
Therefore,the correct dietary supplement is Folic acid and Cobalamin.

(A) Blood coagulation (clotting) is a process that involves the conversion of fibrinogen into fibrin threads,which requires clotting factors.
$1$. Blood serum is the fluid remaining after blood has clotted,meaning it lacks fibrinogen and other clotting factors,so it cannot coagulate.
$2$. Lymph (from the thoracic duct) contains clotting factors and can coagulate,though more slowly than blood.
$3$. Whole blood from the pulmonary vein contains all cellular components and clotting factors,so it will coagulate.
$4$. Blood plasma contains fibrinogen and other clotting factors,so it will coagulate if exposed to the necessary triggers.

(B) Antibodies,also known as immunoglobulins,are a type of protein found in the blood.
They belong to the class of proteins called globulins.
Specifically,they are classified as gamma-globulins.
Therefore,a significant deficiency in antibodies would be reflected in a reduced level of serum globulins in the blood.
Serum albumin is primarily involved in maintaining osmotic pressure,while fibrinogen is essential for blood clotting.
Hemocytes are blood cells,not proteins.
Thus,the correct diagnostic marker is serum globulin.

(C) The $ABO$ blood grouping system is based on the presence or absence of two surface antigens on the red blood cells $(RBCs)$,namely antigen $A$ and antigen $B$.
Individuals with blood group $A$ have antigen $A$ on their $RBCs.
Individuals with blood group $B$ have antigen $B$ on their $RBCs.
Individuals with blood group $AB$ have both antigens $A$ and $B$ on their $RBCs.
Individuals with blood group $O$ do not have either antigen $A$ or antigen $B$ on their $RBCs.
Therefore,the '$O$' in the $ABO$ system represents the absence of both $A$ and $B$ antigens.

(B) In the $ABO$ blood grouping system,individuals with blood group $O$ are known as universal donors because their red blood cells lack both $A$ and $B$ antigens.
This means that blood group $O$ can be safely transfused into individuals of any blood group ($A, B, AB,$ or $O$) without causing an immune reaction.
Since the patient's blood group is unknown and immediate transfusion is required,the safest choice is to use blood from a donor with blood group $O$ to prevent any potential transfusion reaction.

(C) Plasma contains various proteins,including fibrinogen,globulins,and albumins.
$1$. Fibrinogen is a clotting factor synthesized by the liver.
$2$. It is converted into insoluble fibrin threads during the process of blood coagulation (clotting) to form a mesh that traps blood cells.
$3$. Globulins are primarily involved in defense mechanisms,while albumins help in osmotic balance.
Therefore,fibrinogen is the correct answer.

(A) The blood group $O$ negative $(O^-)$ is known as the universal donor.
This is because red blood cells of $O^-$ blood type lack both $A$ and $B$ antigens on their surface and also lack the $Rh$ factor.
Therefore,they do not trigger an immune response (agglutination) when transfused into a recipient of any other blood group.
In emergency situations where the patient's blood group is unknown,$O$ negative blood is the safest choice to prevent transfusion reactions.

(A) In the $ABO$ blood grouping system,individuals with blood group $AB$ have both $A$ and $B$ antigens on the surface of their red blood cells $(RBCs)$.
Because their own immune system recognizes both $A$ and $B$ antigens as 'self',their blood plasma does not contain anti-$A$ or anti-$B$ antibodies.
Consequently,they can receive blood from any other blood group ($A, B, AB,$ or $O$) without triggering an immune reaction against the donor's red blood cells.
Therefore,they are known as universal recipients.

(A) Blood is a fluid connective tissue consisting of plasma and formed elements (RBCs,WBCs,and platelets). When blood clots,the clotting factors (such as fibrinogen) are consumed in the process of forming the fibrin mesh. The clear,straw-colored fluid that remains after the blood has clotted is called serum. Therefore,serum is essentially plasma minus the clotting factors.

(B) Blood platelets (also known as $Thrombocytes$) are cell fragments produced from megakaryocytes in the bone marrow.
They play a crucial role in the process of blood coagulation (clotting).
$A$ reduction in the number of platelets,a condition known as $Thrombocytopenia$,leads to clotting disorders,which can cause excessive bleeding from the body even after minor injuries.

(A) Mature human $RBCs$ (erythrocytes) lose their nucleus and other organelles like mitochondria and endoplasmic reticulum during maturation.
This loss of organelles is an evolutionary adaptation to maximize the internal space available for hemoglobin,which is essential for the efficient transport of $O_2$ throughout the body.
While they do not reproduce (as they are terminally differentiated) and are somatic cells,the primary functional reason for being enucleated is to increase the capacity for $O_2$ transport.
Therefore,statement $(iv)$ is the most appropriate explanation.

(B) Antibodies are specialized proteins known as immunoglobulins,which are a type of globulin protein found in the blood.
Serum globulins are the fraction of blood proteins that include antibodies (IgG,IgM,IgA,IgD,and IgE).
Therefore,to check for a deficiency of antibodies,one would analyze the serum globulin levels in the blood.
Serum albumins are primarily involved in maintaining osmotic pressure,while fibrinogen is involved in blood clotting,and hemocytes are blood cells.