Blood and Blood Group Questions in English

(B) Blood group analysis is based on the inheritance of $ABO$ blood group alleles $(I^A, I^B, i)$.
While it can exclude a man from being the father if his blood group is incompatible with the child's genotype,it cannot definitively prove paternity.
This is because many individuals in the population share the same blood group phenotypes.
Therefore,blood group analysis can only prove that a man cannot be the father,but it cannot confirm paternity with absolute certainty.

(D) The $ABO$ blood group system was discovered by Karl Landsteiner in $1900$.
He identified the presence of antigens on the surface of red blood cells.
For this groundbreaking discovery,he was awarded the Nobel Prize in Physiology or Medicine in $1930$.

(C) The blood group $A$ can have genotypes $I^A I^A$ or $I^A i$. The blood group $O$ has the genotype $ii$.
If the parent with blood group $A$ is homozygous $(I^A I^A)$,the offspring will have genotype $I^A i$ (Blood group $A$).
If the parent with blood group $A$ is heterozygous $(I^A i)$,the offspring will have genotypes $I^A i$ (Blood group $A$) and $ii$ (Blood group $O$).
Therefore,the children can only have blood groups $A$ or $O$.

(C) The child has blood group $B$,which means the child's genotype is either $I^B I^B$ or $I^B i$.
Since the father has blood group $A$,his genotype is either $I^A I^A$ or $I^A i$.
The father cannot contribute the $I^B$ allele required for the child's blood group $B$.
Therefore,the $I^B$ allele must be inherited from the mother.
Individuals with blood group $B$ (genotypes $I^B I^B$ or $I^B i$) or blood group $AB$ (genotype $I^A I^B$) possess the $I^B$ allele.
Thus,the mother must have blood group $B$ or $AB$.

(A) The blood group $AB$ is considered the universal recipient.
This is because individuals with blood group $AB$ possess both $A$ and $B$ antigens on the surface of their red blood cells but lack both anti-$A$ and anti-$B$ antibodies in their plasma.
Consequently,they can receive blood from individuals with any $ABO$ blood group ($A, B, AB,$ or $O$) without triggering an immune reaction.

(D) . Erythroblastosis foetalis is a condition caused by $Rh$ incompatibility between an $Rh$-negative mother and an $Rh$-positive foetus.
During the first pregnancy,the mother's blood is exposed to the foetal $Rh$ antigens,leading to the production of anti-$Rh$ antibodies.
In subsequent pregnancies,these antibodies can cross the placenta and destroy the foetal red blood cells,leading to severe anaemia and jaundice,which may result in the death of the foetus or the newborn.

(D) Individuals with blood group $O$ possess both anti-$A$ and anti-$B$ antibodies in their plasma but lack both $A$ and $B$ antigens on the surface of their red blood cells. Because their immune system would recognize $A$ or $B$ antigens as foreign,they can only receive blood from donors who also have blood group $O$ (which lacks both antigens). Therefore,a person with blood group $O$ can only receive blood from group $O$ donors.

(C) Individuals with blood group $AB$ possess both $A$ and $B$ antigens on the surface of their red blood cells but lack both anti-$A$ and anti-$B$ antibodies in their plasma.
Because they lack these antibodies,they cannot cause an immune reaction (agglutination) against $A$ or $B$ antigens.
However,because they possess both $A$ and $B$ antigens,they can only receive blood from $AB$ donors without triggering an immune response in the recipient.
Therefore,blood from an $AB$ donor can only be safely transfused to a person with blood group $AB$.

(C) The $Rh$ factor is an antigen found on the surface of red blood cells.
It was first discovered in the $Rhesus$ monkey $(Macaca \text{ mulatta})$, from which the name '$Rh$' is derived.
Therefore, the correct option is $(c)$.

(C) The blood group of an individual is determined by the presence of specific antigens on the surface of red blood cells.
Individuals with blood group $AB$ possess both antigen $A$ and antigen $B$ on their red blood cells.
Because they have both antigens,their blood plasma does not contain anti-$A$ or anti-$B$ antibodies.
Therefore,a person with antigens $A$ and $B$ and no antibodies belongs to blood group $AB$.

(B) When an $Rh^-$ woman marries an $Rh^+$ man,the first child is typically $Rh^+$.
During the first pregnancy,some $Rh^+$ fetal blood cells may enter the mother's bloodstream during delivery.
This exposure causes the mother's immune system to produce anti-$Rh$ antibodies.
However,these antibodies are produced in significant amounts only after the first delivery.
Therefore,the first child is nearly always normal and survives.

(D) Individuals with blood group $O$ do not possess $A$ or $B$ antigens on the surface of their $RBC$s.
They possess both anti-$A$ and anti-$B$ antibodies in their plasma.
Because their $RBC$s lack $A$ and $B$ antigens,they do not trigger an immune response in recipients of any blood group.
Therefore,individuals with blood group $O$ are considered universal donors.

(B) The $ABO$ blood grouping system is based on the presence or absence of two surface antigens on the $RBC$s,namely antigen '$A$' and antigen '$B$'.
In blood group '$B$',the $RBC$s possess antigen '$B$' on their surface.
The plasma of an individual with blood group '$B$' contains antibodies against antigen '$A$',which are known as anti-$A$ or '$a$' antibodies.
Therefore,a person with antigen '$B$' on $RBC$s and antibody '$a$' in the plasma belongs to blood group '$B$'.

(A) In the $ABO$ blood grouping system,the blood group of an individual is determined by the presence or absence of specific antigens on the surface of red blood cells $(RBCs)$.
Individuals with blood group $A$ possess antigen $A$ on the surface of their $RBCs$.
These individuals naturally produce antibodies against the antigen they lack,which in this case is antigen $B$. Therefore,they contain antibody $b$ (also known as anti-$B$) in their blood plasma.
Thus,persons with blood group $A$ have antigen $A$ and antibody $b$.

(B) In the $ABO$ blood grouping system,the blood group is determined by the presence of specific antigens on the surface of red blood cells $(RBCs)$.
For an individual with blood group $A$,the $RBCs$ possess antigen $A$ on their surface.
Correspondingly,the plasma (serum) contains antibodies against the antigen that is absent,which in this case is antibody-anti-$B$.
Therefore,a person with blood group $A$ has antigen $A$ on the $RBCs$ and antibody-anti-$B$ in the serum.

(B) The $ABO$ blood grouping system is based on the presence or absence of two surface antigens,namely agglutinogen $A$ and agglutinogen $B$,on the surface of red blood cells $(RBCs)$.
These antigens determine the blood group of an individual.
Therefore,the correct option is $B$.

(A) person with blood group $A$ has $A$ antigens on the surface of their red blood cells and anti-$B$ antibodies in their plasma.
Therefore,they can receive blood from individuals with blood group $A$ (same antigen) or blood group $O$ (no antigens,universal donor).
Receiving blood from group $B$ or $AB$ would cause an immune reaction due to the presence of $B$ antigens,which the recipient's anti-$B$ antibodies would attack.

(D) This condition describes $Erythroblastosis \text{ } foetalis$, which occurs due to $Rh$ incompatibility.
$1$. The mother must be $Rh - ve$ so that her immune system can produce antibodies against $Rh$ antigens.
$2$. The father must be $Rh + ve$ for the foetus to inherit the $Rh$ antigen ($Rh + ve$ foetus).
$3$. During the first pregnancy, the mother is exposed to the $Rh$ antigens of the $Rh + ve$ foetus, leading to the formation of anti-$Rh$ antibodies in her blood.
$4$. In the second pregnancy, these antibodies cross the placenta and destroy the foetal red blood cells, causing severe anaemia. Thus, all the given statements are correct.

(C) Monocytes are a type of agranulocyte white blood cell. They are characterized by a large,kidney-shaped or bean-shaped nucleus. Lymphocytes typically have a large,spherical nucleus that occupies most of the cell. Neutrophils have a multi-lobed nucleus (usually $2-5$ lobes),and eosinophils typically have a bilobed nucleus.

(D) If the parents have blood groups $A$ and $B$,they can be heterozygous for the $O$ allele (genotypes $I^A i$ and $I^B i$).
When these parents cross,the possible genotypes for their offspring are $I^A I^B$ (blood group $AB$),$I^A i$ (blood group $A$),$I^B i$ (blood group $B$),and $ii$ (blood group $O$).
Thus,there are $4$ possible outcomes,and only $1$ of them results in blood group $O$.
Therefore,the probability of having a child with blood group $O$ is $1$ out of $4$.

(D) The mother has blood group $A$, so her possible genotypes are $I^A I^A$ or $I^A i$.
The father has blood group $AB$, so his genotype is $I^A I^B$.
If we cross $I^A I^A \times I^A I^B$, the offspring can have genotypes $I^A I^A$ (Group $A$), $I^A I^B$ (Group $AB$).
If we cross $I^A i \times I^A I^B$, the offspring can have genotypes $I^A I^A$ (Group $A$), $I^A I^B$ (Group $AB$), $I^A i$ (Group $A$), or $I^B i$ (Group $B$).
In both cases, the genotype $ii$ (Group $O$) is impossible because the father must contribute either an $I^A$ or $I^B$ allele to the child. Therefore, the child cannot have blood group $O$.

(D) Blood transfusion is not restricted by biological relationships such as family members. The primary requirement for a successful blood transfusion is the compatibility of the $ABO$ and $Rh$ blood group systems between the donor and the recipient. Therefore,any two individuals,regardless of their relationship,can be donor and recipient if their blood types are compatible.

(A) The blood group is determined by the presence of antigens on the surface of red blood cells.
$1$. If blood coagulates with antiserum $A$,it contains antigen $A$,so the blood group is $A$.
$2$. If blood coagulates with antiserum $B$,it contains antigen $B$,so the blood group is $B$.
$3$. If blood coagulates with both antiserum $A$ and $B$,it contains both antigens $A$ and $B$,so the blood group is $AB$.
$4$. If blood does not coagulate with either antiserum,it contains no antigens,so the blood group is $O$.
Therefore,the statement in option $A$ is correct.

(D) The correct answer is $D$.
In the $ABO$ blood grouping system,a transfusion reaction occurs when the donor's antigens react with the recipient's antibodies.
Group $O$ individuals possess both anti-$A$ and anti-$B$ antibodies in their plasma.
If group $A$ blood (which contains $A$ antigens) is transfused into a group $O$ recipient,the recipient's anti-$A$ antibodies will react with the donor's $A$ antigens,causing agglutination (a transfusion reaction).
Options $A$,$B$,and $C$ represent compatible blood transfusions where no such reaction occurs.

(A) The $Rh$ factor is an antigen found on the surface of red blood cells.
If a person with $Rh^-$ blood receives blood from an $Rh^+$ donor,the recipient's immune system recognizes the $Rh$ antigen as foreign.
This triggers the production of anti-$Rh$ antibodies in the recipient.
These antibodies react with the donor's $Rh^+$ red blood cells,causing them to clump together,a process known as agglutination.
Therefore,$X$ being $Rh^+$ and $Y$ being $Rh^-$ leads to this incompatibility.

(B) The correct answer is $O$.
Blood group $O$ individuals have neither $A$ nor $B$ antigens on the surface of their red blood cells.
Because they lack these antigens,their blood does not trigger an immune response (agglutination) when transfused into patients with other blood types.
Therefore,individuals with blood group $O$ are considered universal donors,and their blood can be safely transfused to a patient with type $A$ blood in an emergency.

(A) Individuals with blood group $O$ are known as universal donors.
This is because their red blood cells lack both $A$ and $B$ antigens on the surface.
Therefore,their blood does not trigger an immune response when transfused into patients with any other blood group ($A$,$B$,$AB$,or $O$).

(A) The $Rh$ factor (or $Rh$ antigen) is a protein found on the surface of red blood cells. It is a critical component used in the classification of human blood groups,alongside the $ABO$ blood group system. Individuals who possess this antigen are termed $Rh$ positive $(Rh^+)$,while those who lack it are termed $Rh$ negative $(Rh^-)$. Therefore,it is directly concerned with blood groups.

(C) The $Rh$ factor (Rhesus factor) was discovered in $1940$ by Karl Landsteiner and Alexander $S$. Weiner. They identified this antigen on the surface of red blood cells in Rhesus monkeys,which is also present in most humans.

(D) The $Rh$ incompatibility problem arises when $Rh^-$ blood is exposed to $Rh^+$ blood.
$1$. Through transfusion: If an $Rh^-$ individual receives $Rh^+$ blood, their immune system produces anti-$Rh$ antibodies.
$2$. During pregnancy: If an $Rh^-$ mother carries an $Rh^+$ fetus, fetal blood may mix with maternal blood during delivery, causing the mother to develop anti-$Rh$ antibodies, which can affect subsequent $Rh^+$ pregnancies (Erythroblastosis fetalis).
Mixing in a test tube is a controlled laboratory procedure and does not represent a physiological 'problem' in the context of clinical pathology.

(B) In erythroblastosis foetalis,the $Rh$ antibodies produced in the mother's blood stream cross the placenta and enter the foetal circulation.
These antibodies attack and destroy the $Rh$-positive red blood cells of the foetus,leading to severe anaemia and jaundice.

(A) The correct answer is $A$.
Blood groups in humans are hereditary traits determined by specific genes.
These traits are inherited from parents to offspring according to Mendel's laws of inheritance.
Other components like haem (a chemical component of hemoglobin) or the presence of a nucleus (which is absent in mature human red blood cells) are not considered hereditary characters in the same context as blood groups.

(C) To analyze blood corpuscles and plasma,the blood must remain in a liquid state (prevented from clotting).
$1$. Heparin is a natural anticoagulant that prevents blood clotting by inhibiting thrombin.
$2$. Sodium oxalate acts as an anticoagulant by chelating calcium ions,which are essential for the coagulation cascade.
$3$. Calcium bicarbonate is a source of calcium ions. Calcium ions $(Ca^{2+})$ are critical factors in the blood clotting process. Adding calcium to a blood sample will promote or accelerate clotting,making it impossible to separate and analyze the plasma and corpuscles effectively.
$4$. Chilled test tubes are often used to slow down metabolic processes and enzymatic reactions,including the clotting cascade,and are acceptable for short-term storage.
Therefore,the test tube containing calcium bicarbonate should not be used.

(B) Blood group systems are classified based on the presence of specific antigens on the surface of red blood cells.
$ABO$,$Rh$,$MN$,$Lewis$,and $Duffy$ are all well-documented human blood group systems recognized by the International Society of Blood Transfusion $(ISBT)$.
'Buffs' and 'Kips' are not recognized blood group systems in human biology.
Therefore,option $B$ is the correct answer.

(B) Individuals with blood group $O$ do not possess either $A$ or $B$ antigens on the surface of their red blood cells.
Because they lack these antigens,their plasma contains both anti-$A$ and anti-$B$ antibodies.
Therefore,the correct statement is that blood group $O$ has no antigens.

(A) The $Rh$ factor causes erythroblastosis foetalis when a woman who is $Rh^-$ develops antibodies against her foetus,which is $Rh^+$.
During delivery,the mother's blood is exposed to the $Rh$ antigens of the foetus,leading to the production of anti-$Rh$ antibodies in the mother's blood.
In subsequent pregnancies,these antibodies can cross the placenta and attack the foetal red blood cells,causing agglutination and destruction of the baby's red blood cells.

(D) The correct answer is $D$.
Blood coagulation is a complex process involving a cascade of clotting factors.
When tissue is damaged or platelets are activated,they release $Thromboplastin$.
$Thromboplastin$ acts as a catalyst in the conversion of inactive $Prothrombin$ into active $Thrombin$ in the presence of $Ca^{2+}$ ions.
Therefore,if $Thromboplastin$ is introduced directly into the bloodstream,it initiates the clotting cascade at that specific site,leading to blood coagulation.

(A) The marriage between an $Rh^+$ male and an $Rh^-$ female should be avoided because it can lead to Erythroblastosis fetalis in the offspring.
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 maternal antibodies can cross the placenta and destroy the fetal red blood cells,causing severe anemia and jaundice in the newborn.

(C) The $O$ blood group is known as the universal donor because it lacks both $A$ and $B$ antigens on the surface of red blood cells.
Furthermore,$Rh^-$ blood is considered safer for emergency transfusions because it lacks the $Rh$ antigen,preventing the risk of anti-$Rh$ antibody formation in an $Rh^-$ recipient.
Therefore,$O, Rh^-$ blood is the safest choice for emergency transfusion when the patient's blood group is unknown.

(D) The correct answer is $(d)$.
In humans,the $ABO$ blood group incompatibility between mother and foetus does not typically lead to the death of the foetus.
$Erythroblastosis \, foetalis$ is a condition that occurs due to $Rh$ factor incompatibility,not $ABO$ blood group incompatibility.
Therefore,the foetus would remain unaffected by the $ABO$ blood group of the mother,whether the foetus has $A, B$ or $AB$ blood group.

(A) The inheritance of $ABO$ blood groups is determined by three alleles: $I^A$,$I^B$,and $i$.
Parents with blood group $O$ have the genotype $ii$.
If both parents have blood group $O$,their genotype is $ii \times ii$.
All offspring from such a cross will have the genotype $ii$,resulting in blood group $O$.
Therefore,it is genetically impossible for parents with blood group $O$ to have a child with blood group $A$.

(C) At normal body temperature,the $Na^+-K^+$ pump (an active transport mechanism) maintains a high concentration of $K^+$ ions inside the $RBC$ compared to the plasma.
When blood is stored at a low temperature $(4^{\circ}C)$,the metabolic activity of the $RBC$ membrane is significantly reduced.
This low temperature inhibits the $Na^+-K^+$ pump,causing active transport to cease.
As a result,$K^+$ ions move down their concentration gradient from the $RBC$ into the plasma,eventually leading to ionic equilibrium.

(D) The blood group $AB$ individuals are known as universal recipients because they can receive blood from any of the four blood groups $(A, B, AB, O)$.
Conversely,individuals with blood group $O$ are universal donors.
In option $(D)$,it suggests $AB$ is the donor and $O$ is the recipient. This is not possible because the $O$ blood group contains both anti-$A$ and anti-$B$ antibodies in the plasma,which would react with the $A$ and $B$ antigens present on the $AB$ donor's red blood cells,leading to agglutination.

(A) The blood group '$O$' is determined by the genotype '$ii$'.
This means the child must have inherited one '$i$' allele from each parent.
If a parent has blood group '$AB$',their genotype is '$I^A I^B$'.
Such a parent can only pass on either the '$I^A$' allele or the '$I^B$' allele to their offspring,but never the '$i$' allele.
Therefore,if one parent has blood group '$AB$',it is impossible for them to have a child with blood group '$O$'.

(D) The genotype of a woman with blood group $O$ is $ii$. Therefore,she can only pass the $i$ allele to her offspring. Since the child has blood group $O$ (genotype $ii$),the child must have received one $i$ allele from the mother and one $i$ allele from the father. $A$ man with blood group $AB$ has the genotype $I^A I^B$. He can only pass either the $I^A$ or $I^B$ allele to his offspring. He cannot pass an $i$ allele. Therefore,it is genetically impossible for a man with blood group $AB$ to be the father of a child with blood group $O$. Thus,the mother is the true parent,but the man claimed as the father cannot be the biological father.

(C) Globulins are a group of proteins present in the blood plasma.
They are primarily synthesized by the liver and the immune system.
Globulins are essential for liver function,blood clotting,and fighting infection.
Specifically,immunoglobulins (also known as antibodies) are a type of globulin that plays a crucial role in the immune response by identifying and neutralizing foreign pathogens like bacteria and viruses.

(D) Leucocytes,also known as white blood cells $(WBCs)$,are referred to as the 'Police guard' of the body.
They play a crucial role in the immune system by defending the body against infectious diseases and foreign invaders.
They identify,engulf,and destroy pathogens like bacteria and viruses,thereby maintaining the body's internal defense mechanism.