Blood and Blood Group Questions in English

(A) Erythroblastosis foetalis occurs when an $Rh^-$ mother carries an $Rh^+$ fetus. During the first delivery,fetal blood may mix with maternal blood,causing the mother to develop anti-Rh antibodies.
To prevent this in subsequent pregnancies,the mother is administered anti-Rh antibodies (RhoGAM) immediately after the delivery of the first $Rh^+$ child.
These injected antibodies destroy any fetal red blood cells that entered the mother's circulation before her immune system can recognize them and produce its own antibodies.
This process is known as passive immunization,which prevents the mother from becoming sensitized to the $Rh$ antigen.

(B) $1$. The volume of blood in an adult is approximately $5-5.5 \; L$,which constitutes $30-35 \; \%$ of the total extracellular fluid. Thus,statements $I$ and $II$ are correct.
$2$. The normal fasting blood glucose level is $80-100 \; mg / 100 \; mL$. Thus,statement $III$ is incorrect.
$3$. The normal cholesterol level in the blood is $50-180 \; mg / 100 \; mL$,which is less than $200 \; mg / 100 \; mL$. Thus,statement $IV$ is correct.
$4$. The normal urea level in the blood is $17-30 \; mg / 100 \; mL$. Thus,statement $V$ is incorrect.
Therefore,the correct statements are $I, II,$ and $IV$.

(D) The fluid that exudes from clotted blood is known as serum.
Serum is essentially plasma from which the clotting factors (such as fibrinogen) have been removed during the process of coagulation.
When blood clots,the formed elements (red blood cells,white blood cells,and platelets) become trapped within the fibrin mesh,leaving behind the clear,yellowish fluid called serum.

(B) The process of formation of red blood cells $(RBCs)$ is known as erythropoiesis.
In adults,this process primarily takes place in the red bone marrow,which is found in the flat bones such as the pelvis,ribs,sternum,and the ends of long bones.

(B) Granulocytes are a type of white blood cells $(WBCs)$. The process of formation of white blood cells is known as leucopoiesis. In adults,the primary site for the production of granulocytes (neutrophils,eosinophils,and basophils) is the bone marrow.

(B) Lymphocytes are agranulocytes $WBC$s,which exist in two main forms,$B$-lymphocytes and $T$-lymphocytes,and these are responsible for the immune response of the body.
Erythrocytes: These are also known as $RBC$s,which help in the transportation of respiratory gases,$O_{2}$ and $CO_{2}$.
Thrombocytes: These are also called platelets and are formed from megakaryocytes (large cells of bone marrow) and are involved in blood clotting.

(A) Diapedesis is the process by which white blood cells (leukocytes) squeeze through the capillary walls to enter the surrounding tissues to fight infection.
This process is primarily characteristic of phagocytic cells such as neutrophils and monocytes.
Since monocytes are the only cells listed that perform diapedesis,the correct answer is $A$.

(C) $Thrombocytes$,also known as blood platelets,are not true cells but are cell fragments. They are produced from large precursor cells in the bone marrow called $megakaryocytes$. These fragments are small,colourless,and enucleated (lack a nucleus),playing a crucial role in the process of blood clotting.

(D) Blood platelets,also known as thrombocytes,play a crucial role in the process of blood coagulation. Upon injury to a blood vessel,platelets adhere to the site of damage and undergo disintegration. During this process,they release various substances,including thromboplastin (also known as platelet factor $3$). This factor initiates the cascade of enzymatic reactions that lead to the formation of a blood clot.

(B) Individuals with blood group $AB$ possess both antigen $A$ and antigen $B$ on the surface of their red blood cells.
However,they do not have any anti-$A$ or anti-$B$ antibodies in their plasma.
Because they lack these antibodies,they can receive blood from any blood group,which is why they are referred to as universal recipients.

(D) In the $ABO$ blood grouping system,individuals with blood group $O$ possess both anti-$A$ and anti-$B$ antibodies in their plasma.
They lack both $A$ and $B$ antigens on the surface of their red blood cells,which makes them universal donors.
However,because they have both anti-$A$ and anti-$B$ antibodies,they can only receive blood from other individuals with blood group $O$.
If a person with blood group $A$ (who has $A$ antigens) donates blood to a person with blood group $O$ (who has anti-$A$ antibodies),the anti-$A$ antibodies will react with the $A$ antigens,leading to agglutination (clumping) of the red blood cells.
Therefore,transfusion from $A$ to $O$ is not possible.

(A) Erythroblastosis foetalis occurs when there is an $Rh$ incompatibility between the mother and the foetus.
Specifically,it happens when the mother is $Rh^{-}$ve and the foetus is $Rh^{+}$ve.
During the first pregnancy,the mother's blood is exposed to the $Rh$ antigens of the foetus during delivery,leading to the production of anti-$Rh$ antibodies in the mother's blood.
In subsequent pregnancies with an $Rh^{+}$ve foetus,these maternal antibodies can cross the placenta and destroy the foetal $RBCs$,causing severe anaemia and jaundice,a condition known as erythroblastosis foetalis.

(D) Blood platelets,upon disintegration,release thromboplastin (platelet factor $3$),which initiates the cascade of blood clotting reactions.

(A) Prothrombin is an inactive plasma protein synthesized by the liver. It circulates in the blood plasma and is converted into thrombin during the process of blood coagulation to facilitate the formation of a fibrin clot.

(A) Prothrombin is an inactive plasma protein synthesized by the liver.
It plays a crucial role in the blood coagulation cascade.
During the process of blood clotting,prothrombin is converted into its active form,thrombin,by the enzyme thrombokinase.

(C) Heparin is a natural anticoagulant produced by mast cells and basophils.
It functions by inhibiting the activity of thrombin and other clotting factors in the blood.
This prevents the formation of blood clots within uninjured blood vessels,ensuring smooth blood flow throughout the circulatory system.

(A) Neutrophils: These are the most abundant leucocytes $(60-65\;\%)$,which possess a phagocytic nature,meaning they engulf harmful germs and are the first to arrive at the site of an infection.
Eosinophils: These constitute $(2-3\;\%)$ of total leucocytes. They are non-phagocytic and their numbers increase during allergic conditions such as asthma or hay fever.
Basophils: These make up $(0-1\;\%)$ of total leucocytes (the least abundant). They release heparin,serotonin,and histamine.

(A) Individuals with blood group $O$ possess neither $A$ nor $B$ antigens on the surface of their red blood cells.
Consequently,their plasma contains both $anti-A$ and $anti-B$ antibodies to protect against foreign antigens.
Therefore,the correct answer is $anti-A$ and $anti-B$.

(D) Blood clotting (coagulation) is a complex process involving a cascade of reactions.
When an injury occurs,platelets and injured tissues release factors that lead to the formation of an enzyme complex called thrombokinase.
This enzyme converts the inactive protein prothrombin present in the plasma into active thrombin in the presence of $Ca^{2+}$ ions.
Subsequently,the active thrombin converts the inactive,soluble fibrinogen present in the plasma into active,insoluble fibrin threads.
These fibrin threads form a network that traps blood cells to form a clot.
Therefore,the conversion of fibrinogen to fibrin by thrombin is a key step in blood clotting.

(A) When blood is lost from the body, the homeostatic mechanisms of the human body are activated to restore blood volume.
$1$. The liquid component (plasma) is rapidly replenished by the absorption of fluids from the interstitial spaces and the intake of water.
$2$. The cellular components (like $RBCs$) are gradually replaced by the bone marrow through the process of erythropoiesis.
$3$. By the next day, the body's regulatory systems, including the release of stored blood from the spleen and fluid shifts, effectively restore the total blood volume back to its normal level of $5 \; \text{litres}$.

(A) When $RBCs$ are placed in distilled water,the surrounding environment is hypotonic relative to the cytoplasm of the $RBC$.
Due to the process of endosmosis,water molecules move from the surrounding into the $RBC$.
This influx of water causes the $RBC$ to swell and eventually burst because they lack a rigid cell wall to withstand the internal osmotic pressure.

(B) The $AB^{+}$ blood group is considered the universal recipient.
This is because individuals with $AB^{+}$ blood possess both $A$ and $B$ antigens on the surface of their red blood cells and have the $Rh$ factor present.
Consequently,their plasma does not contain anti-$A$ or anti-$B$ antibodies,nor does it contain anti-$Rh$ antibodies.
Therefore,they can receive blood from any other blood group without triggering an immune reaction.

(A) The $ABO$ blood grouping system is based on the presence or absence of two surface antigens on the $RBC$s,namely $A$ and $B$.
Individuals with blood group $A$ possess antigen $A$ on their $RBC$s and antibody $b$ (anti-$B$) in their plasma.
Individuals with blood group $B$ possess antigen $B$ on their $RBC$s and antibody $a$ (anti-$A$) in their plasma.
Individuals with blood group $AB$ possess both antigens $A$ and $B$ but no antibodies in their plasma.
Individuals with blood group $O$ possess neither antigen $A$ nor $B$ but have both antibodies $a$ and $b$ in their plasma.
Therefore,a person with antigen $A$ and antibody $b$ belongs to blood group $A$.

(B) The blood type $O$ does not possess any antigens ($A$ or $B$) on the surface of its red blood cells,but it contains both anti-$A$ and anti-$B$ antibodies in the plasma.
Because individuals with blood type $O$ lack both $A$ and $B$ antigens,their blood will not trigger an immune reaction (agglutination) when transfused into a recipient of any blood group.
Therefore,a person with blood type $O$ is considered a universal donor,making it the safest choice for an emergency transfusion when the recipient's blood type is unknown.

(C) Erythroblastosis foetalis is a haemolytic disease of the newborn.
It occurs when an $Rh$-negative mother carries an $Rh$-positive fetus.
During the first pregnancy,the mother's blood is exposed to $Rh$ antigens from the fetus,leading to the production of anti-$Rh$ antibodies.
In subsequent pregnancies,these antibodies can cross the placenta and destroy the fetal red blood cells,causing severe anaemia and jaundice,a condition known as Erythroblastosis foetalis.

(A) The $Rh$ factor causes erythroblastosis foetalis. When an $Rh^-$ woman marries an $Rh^+$ man,the first child (if $Rh^+$) is usually safe because the mother's blood is exposed to the foetal $Rh$ antigens only during the delivery of the first child.
During this process,the mother's immune system develops antibodies against the $Rh$ antigen.
In subsequent pregnancies,these $Rh$ antibodies can cross the placenta and destroy the foetal red blood cells,leading to severe anaemia or jaundice in the foetus.

(B) person with blood group $A$ has $A$ antigens on their red blood cells and anti-$B$ antibodies in their plasma. Therefore,they can receive blood from donors with the same blood group $(A)$ or from donors with no antigens on their red blood cells ($O$ group,which is the universal donor). Thus,they can safely receive blood of type $A$ and type $O$.

(B) The condition described is Erythroblastosis fetalis,which occurs due to $Rh$ incompatibility.
This happens when an $Rh^{-}$ mother carries an $Rh^{+}$ fetus.
During the first pregnancy,the mother's blood is exposed to the $Rh^{+}$ antigens of the fetus,leading to the production of anti-$Rh$ antibodies in the mother's blood.
While the first child is usually unaffected,these antibodies persist in the mother's system.
In subsequent pregnancies,if the fetus is again $Rh^{+}$,these maternal antibodies can cross the placenta and destroy the fetal red blood cells,leading to severe anemia or death.
Therefore,the doctor advises against further pregnancies if the mother is $Rh^{-}$ and the father is $Rh^{+}$.

(C) To determine the possible blood groups of offspring,we analyze the genotypes of the parents.
For a couple with husband of blood group $B$ (genotype $I^B I^B$ or $I^B i$) and wife of blood group $O$ (genotype $ii$):
$1$. If the father is $I^B I^B$,the offspring will have genotypes $I^B i$ (blood group $B$).
$2$. If the father is $I^B i$,the offspring will have genotypes $I^B i$ (blood group $B$) or $ii$ (blood group $O$).
In neither case can an offspring with blood group $A$ (genotype $I^A I^A$ or $I^A i$) be produced,as the father does not possess the $I^A$ allele.

(A) Individuals with blood group-$A$ possess antigen-$A$ on the surface of their $RBCs$ (red blood cells).
Because the immune system recognizes antigen-$A$ as 'self',it produces antibodies against the foreign antigen-$B$,known as Anti-$B$ antibodies.

(B) In the context of blood transfusions,individuals with $O Rh^-$ blood type are considered universal donors because their red blood cells lack $A$,$B$,and $Rh$ antigens,which prevents an immune reaction in the recipient.
Conversely,individuals with $AB Rh^+$ blood are considered universal recipients because their blood contains all these antigens,meaning they do not produce antibodies against them.

(A) person with $AB$ blood group cannot donate blood to others (except those with $AB$ blood group) because their red blood cells contain both $A$ and $B$ antigens,and their plasma lacks both anti-$A$ and anti-$B$ antibodies. However,they can receive blood from all blood groups,which is why they are called universal recipients.

(A) Persons with blood group $AB$ are called universal recipients because both antigens $A$ and $B$ are present on the surface of their red blood cells,and both antibodies $a$ and $b$ are absent in their plasma.
Therefore,such individuals can receive blood from all other blood groups ($A, B, AB,$ and $O$).

(C) The process of blood clotting begins with the release of $Thromboplastin$ from injured tissues or platelets.
$Thromboplastin$ acts as a catalyst in the presence of $Ca^{2+}$ ions to convert inactive prothrombin into active thrombin.
This thrombin then converts soluble fibrinogen into insoluble fibrin threads,which form the clot.
Therefore,$Thromboplastin$ and $Ca^{2+}$ are essential to initiate the coagulation cascade.

(A) $1$. The woman's first child is type $O$,which means the child's genotype is $I^{O} I^{O}$. Since the child inherits one $I^{O}$ allele from each parent,the woman must possess at least one $I^{O}$ allele.
$2$. The woman's second child is type $AB$,which means the child's genotype is $I^{A} I^{B}$. This child must inherit one $I^{A}$ allele from one parent and one $I^{B}$ allele from the other.
$3$. The second husband is type $B$. If he is homozygous $(I^{B} I^{B})$,he contributes $I^{B}$ to the child. If he is heterozygous $(I^{B} I^{O})$,he could contribute either $I^{B}$ or $I^{O}$.
$4$. Since the child is $I^{A} I^{B}$,the $I^{A}$ allele must have come from the mother.
$5$. Combining these facts: The mother must have an $I^{O}$ allele (from the first child) and an $I^{A}$ allele (from the second child). Therefore,her genotype is $I^{A} I^{O}$,which corresponds to blood type $A$.

(A) Basophils: These cells release chemicals such as histamine,serotonin,and heparin. They are primarily involved in inflammatory reactions and allergic responses.
Neutrophils: These are phagocytic cells that engulf and destroy pathogens.
Eosinophils: These cells are primarily involved in allergic reactions and resistance to parasitic infections.
Monocytes: These cells differentiate into macrophages at the site of infection to perform phagocytosis and elicit an immune response.

(C) The Assertion is correct because the $ABO$ blood group phenotype is determined by the presence or absence of specific antigens ($A$ and $B$) on the surface of $RBCs$.
The Reason is incorrect because these antigens are not found on glycophorin. Instead,they are attached to the lipid bilayer of the $RBC$ membrane via glycolipids or glycoproteins. Glycophorin is a specific membrane protein,but it is not the primary carrier for $ABO$ blood group antigens.

(A) During the process of blood coagulation,an injury or trauma stimulates the release of factors that activate a cascade of reactions.
$1$. The enzyme $Thrombin$ is formed from inactive $Prothrombin$ in the presence of the enzyme complex $Thrombokinase$.
$2$. $Thrombin$ then acts as a catalyst to convert the inactive,soluble plasma protein $Fibrinogen$ into insoluble $Fibrin$ threads.
$3$. These $Fibrin$ threads form a network that traps blood cells to form a clot.
Therefore,the correct enzyme responsible for the conversion of $Fibrinogen$ to $Fibrin$ is $Thrombin$.

(D) In the $ABO$ blood grouping system, individuals with $AB$ blood group possess both $A$ and $B$ antigens on the surface of their $RBCs$.
Because their own immune system recognizes both $A$ and $B$ antigens as 'self', they do not produce anti-$A$ or anti-$B$ antibodies in their blood plasma.
Consequently, they can receive blood from individuals with $A$, $B$, $AB$, or $O$ blood types without triggering an immune reaction (agglutination).
Therefore, they are known as "Universal recipients" due to the absence of anti-$A$ and anti-$B$ antibodies in their plasma.

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

(A) Plasma is a straw-coloured,viscous fluid that constitutes approximately $55$ percent of the blood. It serves as the liquid matrix of the blood,containing water,proteins,electrolytes,and other dissolved substances.

(N/A) Fibrinogen: It is a plasma protein essential for blood clotting. It is converted into insoluble fibrin threads by the enzyme thrombin during the coagulation process.
$(b)$ Globulin: These are plasma proteins primarily involved in defense mechanisms of the body,such as the production of antibodies for immunity.
$(c)$ Neutrophils: These are the most abundant phagocytic white blood cells that destroy foreign microorganisms like bacteria by engulfing them.
$(d)$ Lymphocytes: These are specialized white blood cells responsible for the immune response,including the production of antibodies and the destruction of infected cells.

(B) Erythroblastosis foetalis occurs due to $Rh$ incompatibility between an $Rh^{-ve}$ mother and an $Rh^{+ve}$ foetus.
During the first pregnancy,the mother's blood is exposed to the $Rh$ antigens of the foetus,leading to the formation of anti-$Rh$ antibodies in the mother's blood.
In subsequent pregnancies,these antibodies can cross the placenta and enter the foetal circulation.
These antibodies destroy the foetal $RBCs$,leading to severe anaemia and jaundice,a condition known as erythroblastosis foetalis.

(N/A) Blood coagulation is a vital physiological process that occurs in response to an injury or trauma to prevent excessive blood loss.
If blood fails to coagulate,the body cannot seal the damaged blood vessels.
This leads to continuous and uncontrolled bleeding (hemorrhage) from the wound.
Such a situation can result in a significant drop in blood pressure,hypovolemic shock,and can ultimately be fatal due to the massive loss of blood volume.

(A) $PTA$ stands for Plasma Thromboplastin Antecedent.
It is also known as Clotting Factor $XI$.
It plays a crucial role in the intrinsic pathway of the blood coagulation cascade.

(A) The full form of $RBC$ is $Red$ $Blood$ $Cells$.
These are the most common type of blood cells and the vertebrate's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system.

(C) Statement $I$ is incorrect because the network of threads formed during blood coagulation is called fibrin,not thrombin. Thrombin is an enzyme that converts soluble fibrinogen into insoluble fibrin.
Statement $II$ is correct because the spleen acts as the graveyard of erythrocytes (red blood cells),where old and damaged red blood cells are destroyed and recycled.

(A) Blood is a specialized connective tissue that consists of a fluid matrix,plasma,and formed elements. Because it flows through the circulatory system and acts as a transport medium,it is classified as a fluid connective tissue. Bone and cartilage are specialized connective tissues but are skeletal (solid) in nature,not fluid.

(A) Blood is a specialized connective tissue consisting of a fluid matrix,plasma,and formed elements. The formed elements include red blood cells (erythrocytes),white blood cells (leukocytes),and platelets (thrombocytes). Therefore,blood is composed of a fluid matrix and formed elements.

(C) Blood plasma is a straw-colored,viscous fluid that constitutes the matrix of the blood.
It makes up about $55\, \%$ of the total blood volume,while the formed elements (cells) make up the remaining $45\, \%$.
Water constitutes $90-92\, \%$ of plasma,and proteins contribute $6-8\, \%$ of it.
Therefore,the statement that plasma constitutes $45\, \%$ of blood is incorrect,as it actually constitutes $55\, \%$.