Blood and Blood Group Questions in English

(A-Q, B-P, C-R, D-T) The $ABO$ blood grouping system is based on the presence or absence of two surface antigens on the red blood cells,namely $A$ and $B$.
$1$. Blood group $A$ has antigen $A$ on the surface of RBCs.
$2$. Blood group $B$ has antigen $B$ on the surface of RBCs.
$3$. Blood group $AB$ has both antigens $A$ and $B$ on the surface of RBCs.
$4$. Blood group $O$ has no antigens $(NIL)$ on the surface of RBCs.
Therefore,the correct matching is: $(A-q), (B-p), (C-r), (D-t)$.

(A) The $ABO$ blood grouping system is based on the presence or absence of two surface antigens on the red blood cells ($A$ and $B$).
$1$. Individuals with blood group $A$ have antigen $A$ on their RBCs and antibody $b$ (anti-$B$) in their plasma.
$2$. Individuals with blood group $B$ have antigen $B$ on their RBCs and antibody $a$ (anti-$A$) in their plasma.
$3$. Individuals with blood group $AB$ have both antigens $A$ and $B$ on their RBCs and no antibodies $(nil)$ in their plasma.
$4$. Individuals with blood group $O$ have no antigens on their RBCs and both antibodies $a$ and $b$ (anti-$A$ and anti-$B$) in their plasma.
Therefore,the correct matching is: $A-P, B-Q, C-R, D-S$.

(A) The child has blood group $O$,which means the genotype is $ii$.
One $i$ allele is inherited from the father and one $i$ allele is inherited from the mother.
The father has blood group $B$,so his genotype must be $I^B i$ to provide an $i$ allele to the child.
Since the child must receive an $i$ allele from the mother,the mother's genotype must contain at least one $i$ allele.
Possible genotypes for the mother are $I^A i$ (blood group $A$),$I^B i$ (blood group $B$),or $ii$ (blood group $O$).
Blood group $AB$ has the genotype $I^A I^B$,which does not contain an $i$ allele.
Therefore,a mother with blood group $AB$ cannot produce a child with blood group $O$ when the father is blood group $B$.

(B) The blood group of the child is $AB$,which means the genotype is $I^A I^B$.
One allele ($I^A$ or $I^B$) must be inherited from the father and the other from the mother.
The father has blood group $B$,so his genotype is either $I^B I^B$ or $I^B i$.
Since the child must receive the $I^A$ allele from the mother,the mother must possess at least one $I^A$ allele.
Therefore,the mother's genotype must contain $I^A$.
Possible genotypes for the mother are $I^A I^A$,$I^A I^B$,or $I^A i$.
This corresponds to blood groups $A$ or $AB$.
Consequently,the mother cannot have blood group $B$ or $O$ because neither of these contains the $I^A$ allele required for the child to have an $AB$ blood group.

(C) Antibodies,also known as immunoglobulins $(Ig)$,are specialized proteins produced by plasma cells (differentiated $B$-lymphocytes) in response to antigens.
These proteins belong to the class of $\gamma$-globulins (gamma globulins) found in the blood plasma.
Therefore,the correct answer is $\gamma$-globulin.

(D) Agglutinogens are substances that induce an immune response in the body,specifically causing the clumping or agglutination of cells like red blood cells. In biological terminology,these are known as $Antigens$. Since 'Pratijan' is the Hindi/Gujarati term for 'Antigen',options $A$ and $C$ refer to the same concept. Therefore,an agglutinogen is an antigen,which is a substance that can stimulate the production of antibodies. Thus,all the given descriptions are correct.

(A) Diapedesis is the process by which white blood cells (leukocytes),particularly neutrophils and monocytes,squeeze through the pores of the capillary walls to enter the surrounding tissues or $E.C.F.$ (Extracellular Fluid) to reach the site of infection or injury. This is a crucial step in the inflammatory response and the immune system's ability to combat pathogens.

(D) Neutrophils are the most abundant type of white blood cells (leukocytes) in the human body,accounting for approximately $60-70\%$ of the total circulating leukocytes.
They are professional phagocytes that act as the first line of defense against bacterial infections by engulfing and destroying pathogens.
While monocytes can differentiate into macrophages,they are present in much lower numbers in the blood compared to neutrophils.

(C) Leukocytes (white blood cells) are classified into granulocytes and agranulocytes.
$1$. Granulocytes include neutrophils,eosinophils,and basophils.
$2$. Agranulocytes include lymphocytes ($B$-cells and $T$-cells) and monocytes.
$3$. Among all leukocytes,monocytes are the largest in size,typically ranging from $12-20 \ \mu m$ in diameter.
$4$. Therefore,the monocyte is the largest agranulocytic leukocyte.

(C) Option $C$ is the correct answer because Erythroblastosis foetalis occurs only when the foetus is $Rh^{+ve}$ and the mother is $Rh^{-ve}$.
During the first delivery,if $Rh^{+ve}$ foetal blood mixes with the mother's blood,antibodies are produced in the mother's body against the $Rh$ antigen.
These antibodies in successive pregnancies cross the placental barrier and reach the foetus,causing the clumping (agglutination) of $RBCs$ in the foetus.

(A) Phagocytosis is a cellular process where specialized cells engulf and digest pathogens or debris. In the human immune system,$Neutrophils$ and $Monocytes$ are the primary phagocytic white blood cells. $Neutrophils$ are the most abundant leukocytes and act as the first line of defense,while $Monocytes$ differentiate into macrophages to perform phagocytosis.

(B) Bone marrow is the flexible tissue found in the interior of bones.
In humans,red blood cells are produced by the bone marrow located in the cavities of long bones through a process known as haematopoiesis.
Bone marrow is also a key component of the lymphatic system,as it produces lymphocytes that support the body's immune system.

(C) In long bones,a cavity called the bone marrow cavity is present.
This cavity is filled with soft and semi-solid fatty tissue termed as bone marrow.
The bone marrow in certain bones serves as the site for the production of blood cells,including $RBCs$,$WBCs$,and platelets.

(A) Assertion is true because yellow bone marrow acts as a reserve tissue that can produce blood cells when the body's demand increases.
Reason is also true because,in cases of severe blood loss (hemorrhage) or anemia,the body stimulates the conversion of inactive yellow bone marrow into active red bone marrow to accelerate erythropoiesis (the production of red blood cells).

(A) Haemoglobin is the red-coloured respiratory pigment found in the $RBCs$ of most animals.
It consists of a protein called globin and a non-protein prosthetic group called heme.
The heme group contains an iron $(Fe^{2+})$ atom at the center of a porphyrin ring system.
This iron atom is responsible for the reversible binding and transport of oxygen from the lungs to the body tissues,and it also assists in the transport of $CO_{2}$ back to the lungs.

(C) Blood contains various proteins that perform essential functions.
$Albumin$ is a major plasma protein responsible for maintaining osmotic pressure.
$Haemoglobin$ is a conjugated protein found in red blood cells that transports oxygen.
Therefore,both $Albumin$ and $Haemoglobin$ are classified as blood proteins.

(B) White blood cells $(WBCs)$,also known as leukocytes,are 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.
Therefore,granulocytes and agranulocytes are the two main categories of $WBC$.

(B) Thromboplastin is a clotting factor released by traumatised or injured tissues at the site of an injury. It initiates the extrinsic pathway of the blood coagulation cascade. As shown in the process,injured tissue releases thromboplastin,which,along with platelet factors and $Ca^{2+}$ ions,leads to the formation of prothrombinase,eventually resulting in the formation of a blood clot.

(A) $ABO$ blood grouping is based on the presence or absence of two surface antigens,$A$ and $B$,on the surface of $RBCs$.
These antigens are glycoproteins or glycolipids that determine the blood type of an individual.

(C) Fibrinogen (factor $I$) is a soluble plasma glycoprotein,synthesized by the liver.
It is converted by thrombin into fibrin during blood coagulation.
Fibrin is then cross-linked by factor $XIII$ to form a stable blood clot.

(B) To prevent the clotting of collected blood,anticoagulants or specific storage conditions are used.
$1$. Heparin is a natural anticoagulant that prevents blood clotting.
$2$. Sodium oxalate acts as a chelating agent by binding to calcium ions,which are essential for the coagulation cascade.
$3$. Calcium bicarbonate is not an anticoagulant; in fact,calcium ions are required for the blood clotting process. Therefore,adding calcium bicarbonate would promote rather than prevent clotting.
$4$. While low temperatures can slow down enzymatic reactions,simply keeping a test tube at room temperature without any anticoagulant will result in blood coagulation.

(D) Platelets,also known as thrombocytes,are cell fragments produced from large cells in the bone marrow called megakaryocytes.
They are non-nucleated,round or oval,and biconvex in shape.
They are significantly smaller than $RBCs$.
Platelets play a crucial role in the process of blood clotting by releasing substances like thromboplastin.

(A) The $Spleen$ is the largest lymphoid organ in the human body.
It acts as a reservoir for blood, storing red blood cells and platelets.
In emergency situations, such as severe hemorrhage or trauma, the $Spleen$ releases this stored blood into the circulation to help maintain blood volume.
Therefore, it is commonly referred to as the blood bank of the human body.

(B) The primary inorganic constituents of human blood plasma are salts of sodium,chloride,and bicarbonate. Sodium $(Na^+)$ is the most abundant extracellular cation in the blood,playing a critical role in maintaining osmotic pressure and fluid balance. Therefore,sodium is the principal cation in human blood.

(A) Plasma is a straw-coloured,viscous fluid that makes up approximately $55$ $\%$ of the total blood volume.
It consists of $90-92$ $\%$ water,while proteins contribute about $6-8$ $\%$ of the plasma.
The remaining components include inorganic salts,glucose,amino acids,and lipids.
Therefore,the correct values are $A=55, B=90-92, C=6-8$.

(D) $Monocytes$ are the largest agranular leucocytes and are phagocytic in nature. They act as the body's defense by engulfing pathogens. Heparin is an anticoagulant that is primarily secreted by mast cells found in connective tissues, not by monocytes.

(A) Blood platelets (thrombocytes) occur only in mammals.
They are non-nucleated and colourless cell fragments.
They are produced by the fragmentation of large cells called megakaryocytes found in the red bone marrow.
Because they are not complete cells but fragments of cytoplasm derived from megakaryocytes,they are referred to as cell fragments.
They play a crucial role in the process of blood clotting by releasing thromboplastin.

(C) At the site of an injury,blood platelets (thrombocytes) disintegrate and release a chemical substance known as thromboplastin. This substance initiates the blood clotting cascade (coagulation process) by converting prothrombin into thrombin.

(B) universal donor is an individual with blood group $O$ because their red blood cells lack both $A$ and $B$ antigens,preventing an immune reaction in the recipient.
$A$ universal recipient is an individual with blood group $AB$ because their plasma lacks both anti-$A$ and anti-$B$ antibodies,allowing them to receive blood from any $ABO$ blood group type.

(C) The $RBC$s ($Red$ $Blood$ $Cells$) have an average lifespan of approximately $120$ days. After this period,they become fragile and are removed from the circulation. The spleen is the primary organ responsible for filtering and destroying old or damaged $RBC$s. Therefore,the spleen is known as the graveyard of $RBC$s.

(C) Serum is defined as the fluid portion of blood that remains after the clotting process has occurred.
When blood clots,the protein $Fibrinogen$ is converted into $Fibrin$ threads,which form the clot.
Therefore,serum is essentially blood plasma from which $Fibrinogen$ and other clotting factors have been removed.

(C) The average life span of $RBCs$ (Red Blood Cells) is $120$ days.
After this period, they are broken down in the spleen or liver.
The breakdown product of haemoglobin is a yellow-colored pigment called bilirubin, which is normally excreted through bile.
Meanwhile, the iron-containing haeme component is recycled and transferred to the bone marrow for the production of new $RBCs$.
Retention of bilirubin in the body leads to a condition known as jaundice.

(D) Foetus have severe anaemia and jaundice.
$A$ special case of $Rh$ incompatibility has been observed between $Rh-ve$ blood of a pregnant mother and $Rh+ve$ blood of the foetus.
During the delivery of the first child,there is a possibility of exposure of the maternal blood to a small amount of $Rh+ve$ blood from the foetus.
In such cases,the mother starts preparing antibodies against $Rh$ antigen in her blood.
In the case of her subsequent pregnancies,the $Rh$ antibodies from the mother can leak into the blood of the foetus and destroy foetal $RBCs$.
This could be fatal to the foetus or could cause severe anaemia and jaundice to the foetus.
This condition is called erythroblastosis foetalis.

(A) special case of $Rh$ incompatibility is observed between the $Rh-ve$ blood of a pregnant mother and the $Rh+ve$ blood of the foetus.
During the delivery of the first child,there is a possibility of exposure of the maternal blood to a small amount of $Rh+ve$ blood from the foetus.
In such cases,the mother starts preparing antibodies against the $Rh$ antigen in her blood.
In the case of her subsequent pregnancies,the $Rh$ antibodies from the mother can leak into the blood of the foetus and destroy the foetal $RBCs$.
This could be fatal to the foetus or could cause severe anaemia and jaundice to the foetus.
This condition is called erythroblastosis foetalis.

(B) Leucocytes,also known as white blood cells $(WBCs)$,are colourless because they lack the respiratory pigment haemoglobin,which is present in red blood cells $(RBCs)$.
Because they do not contain haemoglobin,they appear white or colourless under a microscope.
They are nucleated and are generally larger than $RBCs$.
The normal count of $WBCs$ in human blood is $6000-8000$ per $mm^3$.
$A$ decrease in their count is known as leukopenia,while an abnormal increase is often associated with conditions like leukaemia.
The average lifespan of $WBCs$ in humans ranges from $10$ to $30$ days.

(C) Lymphocytes constitute about $20-25$ $\%$ of the total white blood cells.
They are characterized by a large,rounded nucleus and are non-motile and non-phagocytic.
They exist in two major forms: $B$-lymphocytes and $T$-lymphocytes.
These cells are essential for the immune response of the body,as they are responsible for the production of antibodies and the regulation of immune functions.

(B) Another antigen,the $Rh$ antigen,similar to the one present in the Rhesus monkey (hence,$Rh$),is also observed on the surface of $RBCs$ of the majority (nearly $80\%$) of humans.
Such individuals are called $Rh$ positive $(Rh^+)$ and those in whom this antigen is absent are called $Rh$ negative $(Rh^-)$.

(C) The largest $RBCs$ among all vertebrates are found in amphibians,specifically in the genus $Amphiuma$,which measure approximately $70-80 \ \mu m$ in diameter.
In mammals,the largest $RBCs$ are found in the elephant,measuring about $9.4 \ \mu m$.
The $RBCs$ of a human are approximately $7.5-8 \ \mu m$ in size.

(A) During the process of blood coagulation,an injury or trauma stimulates the release of thromboplastin from injured tissues and platelet factors from blood platelets. These factors,along with other clotting factors present in the blood,combine to form the enzyme complex known as prothrombinase. This reaction is strictly dependent on the presence of calcium ions $(Ca^{2+})$. Once formed,prothrombinase converts inactive prothrombin into active thrombin.

(A) $pH$ is a measure of the concentration of hydrogen ions in a solution.
Blood is a type of fluid connective tissue.
Blood is slightly alkaline in nature,having an average $pH$ of $7.4$.
It consists of blood cells ($RBCs$,$WBCs$,etc.) and blood plasma.

(D) Prothrombin is a plasma protein synthesized in the liver.
$Vitamin-K$ is essential for the liver to synthesize prothrombin normally.
During the process of blood coagulation,the enzyme prothrombinase converts inactive prothrombin into active thrombin.
Therefore,all the given statements are correct.

(B) Human $RBCs$ (Red Blood Cells) are characterized by the following properties:
$1$. They are devoid of a nucleus (enucleated) in their mature state to provide more space for hemoglobin.
$2$. They are formed in the bone marrow (erythropoiesis).
$3$. They are biconcave in shape,which increases their surface area for efficient $O_2$ transport and allows them to pass through narrow capillaries.
Healing properties and blood clotting are functions associated with platelets and other plasma factors,not $RBCs$.
Therefore,the correct properties are $I, II,$ and $IV$.

(C) When an $Rh^-$ person donates blood to an $Rh^+$ person,the recipient's immune system already recognizes the $Rh$ antigen as 'self' because they possess the $Rh$ factor. Therefore,no anti-$Rh$ antibodies are produced against the donor's blood. This is a safe transfusion,and nothing will happen to either individual.

(D) special case of $Rh$ incompatibility is observed between the $Rh$-negative blood of a pregnant mother and the $Rh$-positive blood of the foetus.
During the delivery of the first child,there is a possibility of exposure of the maternal blood to a small amount of $Rh$-positive blood from the foetus.
In such cases,the mother starts preparing antibodies against the $Rh$ antigen in her blood.
In the case of her subsequent pregnancies,the $Rh$ antibodies from the mother can leak into the blood of the foetus and destroy the foetal $RBCs$.
This could be fatal to the foetus or could cause severe anaemia and jaundice. This condition is called erythroblastosis foetalis.

(A) The doctor suggests this when the male is $Rh^{+}$ (Rh-positive) and the female is $Rh^{-}$ (Rh-negative). This condition leads to Erythroblastosis fetalis. If the mother is $Rh^{-}$ and the fetus is $Rh^{+}$,the mother's immune system may develop antibodies against the $Rh$ antigen during the first pregnancy. In subsequent pregnancies,these antibodies can cross the placenta and destroy the fetal red blood cells,causing severe anemia and jaundice.

(A) Vitamin-$K$,also known as the anti-haemorrhagic factor,is a fat-soluble vitamin. It is essential for the synthesis of prothrombin (clotting factor $II$) in the liver. Without adequate levels of vitamin-$K$,the liver cannot produce sufficient prothrombin,which impairs the blood coagulation process.

(D) The correct answer is $(d)$.
Erythroblastosis foetalis does not occur in the first child because the mother's blood initially lacks $Rh$ antibodies.
During the delivery of the first child,there is a possibility of exposure of the maternal blood to a small amount of $Rh^+$ blood from the foetus.
In such cases,the mother starts preparing $Rh$ antibodies against the $Rh$ antigen in her blood.
Since these antibodies are not present before or during the first pregnancy,the first child remains unaffected.
In subsequent pregnancies,the $Rh$ antibodies from the mother can leak into the blood of the foetus and destroy the foetal $RBCs$,leading to erythroblastosis foetalis.

(A) The process of $RBC$ formation is known as erythropoiesis.
Erythropoietic organs in the foetus include the liver,lymph nodes,and spleen.
After birth,the primary site for erythropoiesis is the red bone marrow.
White bone marrow is not involved in the production of red blood cells.
Therefore,$I, II, III,$ and $V$ are erythropoietic organs,while $IV$ (white bone marrow) is not.

(B) In the $ABO$ blood grouping system,compatibility is determined by the presence of antigens on the surface of red blood cells and antibodies in the plasma.
$1$. Blood group $O$ has no antigens and can donate to $A, B, AB$,and $O$. It is the universal donor.
$2$. Blood group $A$ has antigen $A$ and can donate to $A$ and $AB$.
$3$. Blood group $B$ has antigen $B$ and can donate to $B$ and $AB$.
$4$. Blood group $AB$ has both antigens $A$ and $B$ and can donate only to $AB$. It is the universal recipient.
Option $B$ correctly represents these donor-recipient relationships.

(A) The correct properties of leucocytes are:
$I$. Leucocytes are nucleated cells.
$III$. Their normal count is $6000-8000 \; mm^{-3}$ of blood.
$V$. They are short-lived cells compared to $RBC$s,with a lifespan typically ranging from $10-30$ days.
Therefore,the correct combination is $I, III$ and $V$.