BiologyQ1–55 of 55 questions
Page 1 of 1 · English
1
BiologyMediumMCQAIIMS · 2012
The scientific name of the mango plant is $Mangifera$ $indica$ $(Linn.)$ $Santapau$. In the above name,$Santapau$ refers to:
A
Variety of mango
B
$A$ taxonomist who proposed the present nomenclature in honour of Linnaeus
C
$A$ scientist who for the first time described the mango plant
D
$A$ scientist who changed the name proposed by Linnaeus and proposed the present name
Solution
(D) The collection of rules regarding the scientific nomenclature of plants is known as $ICBN$ (International Code of Botanical Nomenclature).
According to $ICBN$ rules,if a scientist changes the name originally proposed by another scientist,the name of the original author is written in parentheses,followed by the name of the scientist who proposed the new name.
In the name $Mangifera$ $indica$ $(Linn.)$ $Santapau$,$Linn.$ (Linnaeus) is the original author,and $Santapau$ is the scientist who corrected or proposed the current nomenclature.
According to $ICBN$ rules,if a scientist changes the name originally proposed by another scientist,the name of the original author is written in parentheses,followed by the name of the scientist who proposed the new name.
In the name $Mangifera$ $indica$ $(Linn.)$ $Santapau$,$Linn.$ (Linnaeus) is the original author,and $Santapau$ is the scientist who corrected or proposed the current nomenclature.
0 likesView Solution
2
BiologyEasyMCQAIIMS · 2012
The classification of Linnaeus was mainly based on
A
Sepals
B
Carpels
C
Petals
D
Stamens
Solution
(D) The classification system proposed by Carolus Linnaeus is known as an artificial system of classification.
Linnaeus classified the plant kingdom primarily based on reproductive characteristics,specifically focusing on two main features: $(1)$ the number and arrangement of stamens and $(2)$ the characteristics of the style.
Therefore,the correct option is $D$.
Linnaeus classified the plant kingdom primarily based on reproductive characteristics,specifically focusing on two main features: $(1)$ the number and arrangement of stamens and $(2)$ the characteristics of the style.
Therefore,the correct option is $D$.
0 likesView Solution
3
BiologyEasyMCQAIIMS · 2012
Sporocarp is a reproductive structure of
A
Some algae
B
Some aquatic ferns having sori
C
Angiosperms having spores
D
Bryophytes
Solution
(B) Sporocarp is a reproductive structure found in some aquatic ferns,such as $Marsilea$.
Sporocarps are functionally and developmentally modified leaves that bear several sori.
Each sorus consists of two types of sporangia: megasporangia,which produce large female megaspores,and microsporangia,which produce many small male microspores.
Sporocarps are functionally and developmentally modified leaves that bear several sori.
Each sorus consists of two types of sporangia: megasporangia,which produce large female megaspores,and microsporangia,which produce many small male microspores.
0 likesView Solution
4
BiologyEasyMCQAIIMS · 2012
"Portuguese man of war" is
A
Soldier of world war $I$
B
Portuguese soldier
C
$A$ sponge
D
$A$ polymorphic, colonial, coelenterate
Solution
(D) "Portuguese man of war" is a polymorphic, colonial coelenterate known as $Physalia \ physalis$.
It is named so due to its appearance, which resembles Portuguese warships (caravels) sailing in the sea during the $15^{th}$ and $16^{th}$ centuries.
It is named so due to its appearance, which resembles Portuguese warships (caravels) sailing in the sea during the $15^{th}$ and $16^{th}$ centuries.
0 likesView Solution
5
BiologyMediumMCQAIIMS · 2012
Which are exclusively viviparous?
A
Bony fishes
B
Cartilaginous fishes
C
Sharks
D
Whales
Solution
(D) Whales are exclusively viviparous. In viviparous animals (the majority of mammals,including human beings),the zygote develops into a young one inside the body of the female organism.
After attaining a certain stage of growth,the young ones are delivered out of the body of the female organism.
After attaining a certain stage of growth,the young ones are delivered out of the body of the female organism.
0 likesView Solution
6
BiologyMediumMCQAIIMS · 2012
Assertion : Acraniata is a group of organisms which do not have a distinct cranium.
Reason : It includes small marine forms without a head.
Reason : It includes small marine forms without a head.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(A) Acraniata (also known as Protochordata) is a group of chordates that lack a distinct cranium (brain box) and a vertebral column.
These organisms are exclusively marine and lack a well-defined head region,which is why they are often referred to as 'acraniates'.
Since the absence of a cranium is directly linked to the lack of a developed head region in these primitive chordates,the Reason correctly explains the Assertion.
These organisms are exclusively marine and lack a well-defined head region,which is why they are often referred to as 'acraniates'.
Since the absence of a cranium is directly linked to the lack of a developed head region in these primitive chordates,the Reason correctly explains the Assertion.
0 likesView Solution
7
BiologyMediumMCQAIIMS · 2012
Prickles of rose are
A
Modified leaves
B
Modified stipules
C
Exogenous in origin
D
Endogenous in origin
Solution
(C) Prickles of rose develop only from the cortex and epidermis and are found at the nodes or internodes.
They help in climbing and protection.
Since they arise from the superficial layers (cortex and epidermis),they are exogenous in origin.
They help in climbing and protection.
Since they arise from the superficial layers (cortex and epidermis),they are exogenous in origin.
0 likesView Solution
8
BiologyMediumMCQAIIMS · 2012
If a stem is girdled,what happens?
A
Root dies first
B
Shoot dies first
C
Both die together
D
None of the above would die
Solution
(A) Girdling involves the removal of a ring of bark (including the phloem) from the stem. Since the phloem is responsible for the translocation of food (sucrose) from the leaves to the roots,girdling prevents this transport. Consequently,the roots are deprived of nutrients and die first,followed by the death of the entire plant.
0 likesView Solution
9
BiologyDifficultMCQAIIMS · 2012
Three morphological forms of the Golgi complex are:
A
Lamellae,tubules and vesicles
B
Cisternae,tubules and vesicles
C
Cisternae,tubules and lamellae
D
Granum,thylakoids and vesicles
Solution
(B) The three morphological forms of the Golgi complex are cisternae,tubules,and vesicles.
$1$. Cisternae: These are flattened,disc-shaped sacs stacked parallel to each other. They have a distinct convex $cis$ (forming) face and a concave $trans$ (maturing) face.
$2$. Tubules: These are tubular structures associated with the periphery of the cisternae.
$3$. Vesicles: These are small,spherical,or oval structures that bud off from the tubules or cisternae,involved in the transport of materials.
$1$. Cisternae: These are flattened,disc-shaped sacs stacked parallel to each other. They have a distinct convex $cis$ (forming) face and a concave $trans$ (maturing) face.
$2$. Tubules: These are tubular structures associated with the periphery of the cisternae.
$3$. Vesicles: These are small,spherical,or oval structures that bud off from the tubules or cisternae,involved in the transport of materials.
0 likesView Solution
10
BiologyMediumMCQAIIMS · 2012
Which chromosome may be lost during cell division?
A
Giant chromosome
B
Acentric chromosome
C
Polycentric chromosome
D
Telocentric chromosome
Solution
(B) An acentric chromosome is a chromosome that lacks a centromere.
Because it lacks a centromere,it cannot attach to the spindle fibers during cell division.
Consequently,it fails to move to the poles during anaphase and is often lost or excluded from the daughter nuclei.
Because it lacks a centromere,it cannot attach to the spindle fibers during cell division.
Consequently,it fails to move to the poles during anaphase and is often lost or excluded from the daughter nuclei.
0 likesView Solution
11
BiologyMediumMCQAIIMS · 2012
Assertion : Allosteric enzymes show feedback inhibition.
Reason : The inhibitor is competitive.
Reason : The inhibitor is competitive.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(C) Feedback inhibition is a type of reversible inhibition observed in allosteric enzymes.
In this process,the end product of a metabolic pathway acts as an inhibitor for an enzyme that functions early in the pathway.
The inhibitor in feedback inhibition is non-competitive,not competitive.
It binds to an allosteric site,which is distinct from the active site,causing a conformational change in the enzyme that reduces its activity.
Therefore,the Assertion is correct,but the Reason is incorrect.
In this process,the end product of a metabolic pathway acts as an inhibitor for an enzyme that functions early in the pathway.
The inhibitor in feedback inhibition is non-competitive,not competitive.
It binds to an allosteric site,which is distinct from the active site,causing a conformational change in the enzyme that reduces its activity.
Therefore,the Assertion is correct,but the Reason is incorrect.
0 likesView Solution
12
BiologyMediumMCQAIIMS · 2012
Assertion : Interphase is resting stage.
Reason : The interphase cell is metabolically inactive.
Reason : The interphase cell is metabolically inactive.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(D) Previously,interphase was called the resting stage because there is no apparent morphological activity related to cell division.
However,the interphase cell is metabolically quite active.
Interphase consists of three subphases ($G_1$,$S$,and $G_2$).
Synthesis of $DNA$ occurs in the $S$ phase.
$G_1$ is the period between the end of mitosis and the start of the $S$ phase.
$G_2$ is the phase between the $S$ phase and the next mitosis.
As the synthesis of $DNA$ and proteins occurs during interphase,it is considered a metabolically active phase.
Therefore,the Assertion is incorrect because it is not a resting stage,and the Reason is incorrect because the cell is metabolically active.
However,the interphase cell is metabolically quite active.
Interphase consists of three subphases ($G_1$,$S$,and $G_2$).
Synthesis of $DNA$ occurs in the $S$ phase.
$G_1$ is the period between the end of mitosis and the start of the $S$ phase.
$G_2$ is the phase between the $S$ phase and the next mitosis.
As the synthesis of $DNA$ and proteins occurs during interphase,it is considered a metabolically active phase.
Therefore,the Assertion is incorrect because it is not a resting stage,and the Reason is incorrect because the cell is metabolically active.
0 likesView Solution
13
BiologyMediumMCQAIIMS · 2012
Excessive loss of water causes wilting of leaves; it can be prevented by:
A
Keeping the plant in bright light
B
Spraying the plant with alcohol
C
Applying vaseline on the leaf surface
D
Adding high amounts of fertilizers to the soil
Solution
(C) Excessive loss of water from the leaves occurs due to transpiration.
Applying vaseline on the leaf surface creates a physical barrier that blocks the stomata.
By closing the stomata,the exit of water vapor is restricted,thereby preventing excessive water loss and subsequent wilting of the leaves.
Applying vaseline on the leaf surface creates a physical barrier that blocks the stomata.
By closing the stomata,the exit of water vapor is restricted,thereby preventing excessive water loss and subsequent wilting of the leaves.
0 likesView Solution
14
BiologyMediumMCQAIIMS · 2012
Assertion : Long distance flow of photoassimilates in plants occurs through sieve tubes.
Reason : Mature sieve tubes have parietal cytoplasm and perforated sieve plates.
Reason : Mature sieve tubes have parietal cytoplasm and perforated sieve plates.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(A) The assertion is correct because sieve tubes are the primary conducting elements for the translocation of photoassimilates (sucrose) in plants.
The reason is also correct because mature sieve tube elements lack a nucleus but retain a thin layer of parietal cytoplasm and possess perforated sieve plates at their end walls.
These structural features facilitate the mass flow of sap from one sieve tube element to the next,making the reason a correct explanation for the assertion.
The reason is also correct because mature sieve tube elements lack a nucleus but retain a thin layer of parietal cytoplasm and possess perforated sieve plates at their end walls.
These structural features facilitate the mass flow of sap from one sieve tube element to the next,making the reason a correct explanation for the assertion.
0 likesView Solution
15
BiologyEasyMCQAIIMS · 2012
Which one of the following elements is not an essential micronutrient for plant growth?
A
$Ca$
B
$Mn$
C
$Zn$
D
$Cu$
Solution
(A) Essential elements are divided into macronutrients and micronutrients based on their quantitative requirements.
Macronutrients are required in large amounts (e.g.,$C, H, O, N, P, K, S, Mg, Ca$).
Micronutrients are required in very small amounts (trace amounts). These include $Fe, Mn, Cu, Mo, Zn, B, Cl,$ and $Ni$.
Among the given options,$Ca$ (Calcium) is a macronutrient,while $Mn, Zn,$ and $Cu$ are micronutrients.
Therefore,$Ca$ is not a micronutrient.
Macronutrients are required in large amounts (e.g.,$C, H, O, N, P, K, S, Mg, Ca$).
Micronutrients are required in very small amounts (trace amounts). These include $Fe, Mn, Cu, Mo, Zn, B, Cl,$ and $Ni$.
Among the given options,$Ca$ (Calcium) is a macronutrient,while $Mn, Zn,$ and $Cu$ are micronutrients.
Therefore,$Ca$ is not a micronutrient.
0 likesView Solution
16
BiologyEasyMCQAIIMS · 2012
Which element plays an important role in nitrogen fixation?
A
$Mn$
B
$Mo$
C
$Zn$
D
$Cu$
Solution
(B) Molybdenum $(Mo)$ is a crucial micronutrient that plays an essential role in nitrogen fixation.
It is a key component of the enzyme nitrogenase,which is responsible for the reduction of atmospheric nitrogen to ammonia in leguminous plants.
Plants typically require molybdenum in concentrations ranging from $0.1$ to $2.5 \, ppm$ in their tissues for normal growth and metabolic processes.
The availability of molybdenum in the soil is highly dependent on soil type,being highest in organic soils,lower in clay soils,and least in sandy soils.
It is a key component of the enzyme nitrogenase,which is responsible for the reduction of atmospheric nitrogen to ammonia in leguminous plants.
Plants typically require molybdenum in concentrations ranging from $0.1$ to $2.5 \, ppm$ in their tissues for normal growth and metabolic processes.
The availability of molybdenum in the soil is highly dependent on soil type,being highest in organic soils,lower in clay soils,and least in sandy soils.
0 likesView Solution
17
BiologyEasyMCQAIIMS · 2012
The family in which many plants are $C_4$ type is:
A
Malvaceae
B
Solanaceae
C
Cruciferae
D
Gramineae
Solution
(D) $C_4$ cycle occurs in $1500$ species of $19$ angiospermic families. Most of these plants are monocots,which primarily belong to the families Gramineae (Poaceae) and Cyperaceae.
0 likesView Solution
18
BiologyMediumMCQAIIMS · 2012
In the electron transport chain during terminal oxidation,the cytochrome,which donates electrons to $O_2$ is
A
Cytochrome $-b$
B
Cytochrome $-c$
C
Cytochrome $-a_3$
D
Cytochrome $-f$
Solution
(C) In the $ETS$ (Electron Transport System) or respiratory chain,there are several cytochromes including $b$,$c_1$,$c$,$a$,and $a_3$.
Cytochrome $a_3$ is the terminal cytochrome of the $ETS$.
It is responsible for donating electrons directly to $O_2$,which acts as the final electron acceptor.
This process leads to the reduction of $O_2$ and the formation of metabolic water.
Cytochrome $a_3$ is the terminal cytochrome of the $ETS$.
It is responsible for donating electrons directly to $O_2$,which acts as the final electron acceptor.
This process leads to the reduction of $O_2$ and the formation of metabolic water.
0 likesView Solution
19
BiologyMediumMCQAIIMS · 2012
Assertion : Cyclic pathway of photosynthesis first appeared in some eubacterial species.
Reason : Oxygen started accumulating in the atmosphere after the non-cyclic pathway of photosynthesis evolved.
Reason : Oxygen started accumulating in the atmosphere after the non-cyclic pathway of photosynthesis evolved.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(A) The cyclic pathway of photosynthesis is considered the most primitive form,appearing first in some eubacterial species. It is the earliest mechanism for $ATP$ production using light energy.
Non-cyclic photophosphorylation involves the photolysis of water,where water molecules are split into oxygen and hydrogen under the influence of light and chlorophyll. This process is the primary natural source of molecular oxygen in the atmosphere. Therefore,oxygen accumulation began only after the evolution of the non-cyclic pathway. Both statements are correct,and the Reason explains why oxygen accumulation is linked to the evolution of the non-cyclic pathway.
Non-cyclic photophosphorylation involves the photolysis of water,where water molecules are split into oxygen and hydrogen under the influence of light and chlorophyll. This process is the primary natural source of molecular oxygen in the atmosphere. Therefore,oxygen accumulation began only after the evolution of the non-cyclic pathway. Both statements are correct,and the Reason explains why oxygen accumulation is linked to the evolution of the non-cyclic pathway.
0 likesView Solution
20
BiologyMediumMCQAIIMS · 2012
The enzymes of the $TCA$ cycle are located in the mitochondrial matrix,except for one which is located in the inner mitochondrial membrane in eukaryotes and in the cytosol in prokaryotes. This enzyme is:
A
Succinate dehydrogenase
B
Lactate dehydrogenase
C
Isocitrate dehydrogenase
D
Malate dehydrogenase
Solution
(A) All the oxidative enzymes of the $TCA$ cycle are located in the mitochondrial matrix,except for succinate dehydrogenase.
This enzyme catalyzes the conversion of succinic acid into fumaric acid.
It is an integral protein complex that is tightly bound to the inner mitochondrial membrane.
In fact,this enzyme is the preferred marker enzyme for the inner mitochondrial membrane during mitochondrial fractionation.
This enzyme catalyzes the conversion of succinic acid into fumaric acid.
It is an integral protein complex that is tightly bound to the inner mitochondrial membrane.
In fact,this enzyme is the preferred marker enzyme for the inner mitochondrial membrane during mitochondrial fractionation.
0 likesView Solution
21
BiologyEasyMCQAIIMS · 2012
Parotid salivary glands are present
A
Below the tongue
B
Below the cheeks
C
In the angle between two jaws
D
Below the eye orbits
Solution
(B) There are three pairs of salivary glands in humans.
$1$. Parotid glands: These are the largest salivary glands and are located below the cheeks,near the ears.
$2$. Submaxillary or submandibular glands: These are located in the angle between the two jaws.
$3$. Sublingual glands: These are located below the tongue.
$1$. Parotid glands: These are the largest salivary glands and are located below the cheeks,near the ears.
$2$. Submaxillary or submandibular glands: These are located in the angle between the two jaws.
$3$. Sublingual glands: These are located below the tongue.
0 likesView Solution
22
BiologyEasyMCQAIIMS · 2012
Volume of air breathed in and out during normal breathing is called
A
Vital capacity
B
$IRV$
C
$ERV$
D
Tidal volume
Solution
(D) The volume of air inspired or expired during a normal breath is known as tidal volume $(TV)$.
It is approximately $500\, ml$.
$A$ healthy human can inspire or expire approximately $6000$ to $8000\, ml$ of air per minute,given that the normal breathing rate is $12-16$ times per minute.
It is approximately $500\, ml$.
$A$ healthy human can inspire or expire approximately $6000$ to $8000\, ml$ of air per minute,given that the normal breathing rate is $12-16$ times per minute.
0 likesView Solution
23
BiologyEasyMCQAIIMS · 2012
The much developed larynx of a human male is called:
A
Aristotle's lantern
B
Syrinx
C
Adam's apple
D
Muller's organ
Solution
(C) The larynx is a cartilaginous box that helps in sound production and is therefore known as the sound box. In human males, the larynx becomes more prominent during puberty due to the influence of androgens, and this enlarged structure is commonly referred to as the $Adam's apple$.
0 likesView Solution
24
BiologyMediumMCQAIIMS · 2012
Assertion : Inspiration occurs due to muscular relaxation.
Reason : During inspiration,the diaphragm and external intercostal muscle contract simultaneously.
Reason : During inspiration,the diaphragm and external intercostal muscle contract simultaneously.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If both the Assertion and Reason are incorrect.
D
If the Assertion is correct but Reason is incorrect.
Solution
(D) Inspiration is an active process that occurs due to the contraction of muscles.
The diaphragm and external intercostal muscles contract simultaneously during inspiration.
This contraction increases the volume of the thoracic cavity in the antero-posterior and dorso-ventral axes,leading to a decrease in intrapulmonary pressure,which allows air to flow into the lungs.
Since the assertion states that inspiration occurs due to muscular relaxation,it is incorrect.
However,the reason correctly states that the diaphragm and external intercostal muscles contract during inspiration.
Therefore,the assertion is incorrect,but the reason is correct.
The diaphragm and external intercostal muscles contract simultaneously during inspiration.
This contraction increases the volume of the thoracic cavity in the antero-posterior and dorso-ventral axes,leading to a decrease in intrapulmonary pressure,which allows air to flow into the lungs.
Since the assertion states that inspiration occurs due to muscular relaxation,it is incorrect.
However,the reason correctly states that the diaphragm and external intercostal muscles contract during inspiration.
Therefore,the assertion is incorrect,but the reason is correct.
0 likesView Solution
25
BiologyMediumMCQAIIMS · 2012
Assertion : Blood is coloured in the insects.
Reason : Insect blood has no role in $O_2$ transport.
Reason : Insect blood has no role in $O_2$ transport.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(D) The blood of insects,known as hemolymph,is colourless because it lacks respiratory pigments like hemoglobin. Therefore,the Assertion is incorrect. The Reason is correct because insect blood does not transport $O_2$; instead,insects utilize a tracheal system for gas exchange,where air is delivered directly to tissues via tracheae.
0 likesView Solution
26
BiologyMediumMCQAIIMS · 2012
In which of the following is the minimum content of urea present?
A
Hepatic portal vein
B
Portal vein
C
Renal vein
D
Vena cava
Solution
(C) The renal vein carries blood away from the kidneys after the process of filtration and reabsorption.
Since the kidneys are responsible for removing nitrogenous wastes like urea from the blood,the blood exiting the kidneys via the renal vein contains the lowest concentration of urea compared to other major blood vessels in the body.
Therefore,the renal vein has the minimum content of urea.
Since the kidneys are responsible for removing nitrogenous wastes like urea from the blood,the blood exiting the kidneys via the renal vein contains the lowest concentration of urea compared to other major blood vessels in the body.
Therefore,the renal vein has the minimum content of urea.
0 likesView Solution
27
BiologyEasyMCQAIIMS · 2012
The $Duct$ of $Bellini$ is concerned with
A
Filtration of urine
B
Purification of urine
C
Conduction of urine
D
All the above
Solution
(C) The $Duct$ of $Bellini$ refers to the terminal part of the collecting ducts in the kidney.
These ducts are responsible for the conduction of urine from the nephrons to the renal pelvis.
They do not perform filtration or purification; their primary function is the transport of urine.
These ducts are responsible for the conduction of urine from the nephrons to the renal pelvis.
They do not perform filtration or purification; their primary function is the transport of urine.
0 likesView Solution
28
BiologyMediumMCQAIIMS · 2012
Assertion : In vertebrates,the liver is also referred to as an accessory excretory organ.
Reason : Liver helps kidneys in the secretion of urine.
Reason : Liver helps kidneys in the secretion of urine.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(C) In vertebrates,the lungs,liver,and skin are referred to as accessory excretory organs because,besides the urinary system,these organs also participate in the removal of waste products from the body.
The liver is the principal organ for the excretion of cholesterol,bile pigments (bilirubin and biliverdin),inactivated products of steroid hormones,some vitamins,and many drugs.
It secretes these substances into the bile and indirectly helps by the formation of urea through amino acids in the ornithine cycle.
The liver has no role in the secretion of urine; urine secretion is the primary function of the kidneys.
The liver is the principal organ for the excretion of cholesterol,bile pigments (bilirubin and biliverdin),inactivated products of steroid hormones,some vitamins,and many drugs.
It secretes these substances into the bile and indirectly helps by the formation of urea through amino acids in the ornithine cycle.
The liver has no role in the secretion of urine; urine secretion is the primary function of the kidneys.
0 likesView Solution
29
BiologyEasyMCQAIIMS · 2012
Sesamoid bone is derived from
A
Cartilage
B
Areolar tissue
C
Tendon
D
Ligament
Solution
(C) Sesamoid bones are small,rounded bones that are embedded within certain tendons.
These bones are typically found where a tendon passes over a joint,such as in the hand,knee (e.g.,the patella),and foot.
Functionally,they act to protect the tendon from excessive wear and tear and improve the mechanical advantage of the joint by increasing the leverage of the muscle.
These bones are typically found where a tendon passes over a joint,such as in the hand,knee (e.g.,the patella),and foot.
Functionally,they act to protect the tendon from excessive wear and tear and improve the mechanical advantage of the joint by increasing the leverage of the muscle.
0 likesView Solution
30
BiologyMediumMCQAIIMS · 2012
Assertion : Ball and socket joints are the most mobile joints.
Reason : Synovial fluid is present here.
Reason : Synovial fluid is present here.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(B) The Assertion is correct because ball and socket joints allow movement in many planes,making them the most mobile joints in the body.
The Reason is also correct because these joints are a type of synovial joint,which contains synovial fluid to reduce friction.
However,the presence of synovial fluid is a characteristic of all synovial joints,not the specific reason why ball and socket joints are the most mobile. The primary reason for their high mobility is the structural arrangement where a spherical head of one bone fits into a cup-like cavity of another bone.
Therefore,both statements are correct,but the Reason is not the correct explanation of the Assertion.
The Reason is also correct because these joints are a type of synovial joint,which contains synovial fluid to reduce friction.
However,the presence of synovial fluid is a characteristic of all synovial joints,not the specific reason why ball and socket joints are the most mobile. The primary reason for their high mobility is the structural arrangement where a spherical head of one bone fits into a cup-like cavity of another bone.
Therefore,both statements are correct,but the Reason is not the correct explanation of the Assertion.
0 likesView Solution
31
BiologyMediumMCQAIIMS · 2012
Assertion : Intercalated discs are important regions of cardiac muscle cells.
Reason : Intercalated discs function as boosters for muscle contraction waves.
Reason : Intercalated discs function as boosters for muscle contraction waves.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(A) Cardiac muscle cells are short,cylindrical cells joined end-to-end and by side branching to form a network.
Intercalated discs are the dense junctions formed between cardiac muscle cells where they meet each other.
These discs are specialized regions of the cell membranes that allow the rapid transmission of electrical impulses.
Since cardiac muscle possesses considerable rhythmicity and generates its own wave of excitation,these discs function as boosters for the muscle contraction wave,ensuring that the heart contracts as a single unit (syncytium).
Intercalated discs are the dense junctions formed between cardiac muscle cells where they meet each other.
These discs are specialized regions of the cell membranes that allow the rapid transmission of electrical impulses.
Since cardiac muscle possesses considerable rhythmicity and generates its own wave of excitation,these discs function as boosters for the muscle contraction wave,ensuring that the heart contracts as a single unit (syncytium).
0 likesView Solution
32
BiologyMediumMCQAIIMS · 2012
Bipolar nerve cells are present in
A
Skin tactile corpuscles
B
Spinal cord
C
Retina of eye
D
All the above
Solution
(C) Bipolar neurons are nerve cells that have two extensions: one axon and one dendrite.
These cells are specialized sensory neurons for the transmission of special senses.
They are found in the retina of the eye,the olfactory epithelium of the nose,and the ganglia of the vestibulocochlear nerve ($VIII$ cranial nerve).
These cells are specialized sensory neurons for the transmission of special senses.
They are found in the retina of the eye,the olfactory epithelium of the nose,and the ganglia of the vestibulocochlear nerve ($VIII$ cranial nerve).
0 likesView Solution
33
BiologyMediumMCQAIIMS · 2012
Fenestra ovalis is the opening of
A
Cranium
B
Tympanum
C
Tympanic cavity
D
Brain
Solution
(C) The $Fenestra ovalis$ (also known as the oval window) is a membrane-covered opening that connects the middle ear (tympanic cavity) to the inner ear (vestibule).
It allows the vibrations from the ossicles to be transmitted to the fluid within the cochlea.
It allows the vibrations from the ossicles to be transmitted to the fluid within the cochlea.
0 likesView Solution
34
BiologyMediumMCQAIIMS · 2012
Multipolar nerve cells are present in
A
Cochlea
B
Dorsal root ganglia of spinal cord
C
Retina of eye
D
Brain
Solution
(D) Multipolar neurons are characterized by having one axon and two or more dendrites. They are the most common type of neurons in the vertebrate nervous system and are found in the cerebral cortex of the brain and the spinal cord. In contrast,bipolar neurons are found in the retina of the eye,and pseudounipolar neurons are found in the dorsal root ganglia of the spinal cord.
0 likesView Solution
35
BiologyMediumMCQAIIMS · 2012
Assertion : The brain stem contains centres for controlling activities.
Reason : Brain stem is very sensitive.
Reason : Brain stem is very sensitive.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(C) The brain stem consists of the midbrain,pons,and medulla oblongata.
It acts as a vital connection between the brain and the spinal cord.
It contains centers that control many involuntary vital activities such as respiration,cardiovascular reflexes,and gastric secretions.
Therefore,the Assertion is correct.
However,the statement that the brain stem is 'very sensitive' is a vague and scientifically inaccurate description of its function or physiological property in this context.
Thus,the Reason is incorrect.
It acts as a vital connection between the brain and the spinal cord.
It contains centers that control many involuntary vital activities such as respiration,cardiovascular reflexes,and gastric secretions.
Therefore,the Assertion is correct.
However,the statement that the brain stem is 'very sensitive' is a vague and scientifically inaccurate description of its function or physiological property in this context.
Thus,the Reason is incorrect.
0 likesView Solution
36
BiologyMediumMCQAIIMS · 2012
Which gland is concerned with salt equilibrium in the body?
A
Anterior pituitary
B
Pancreas
C
Adrenal
D
Thyroid
Solution
(C) Adrenal glands are concerned with salt equilibrium in the body.
Mineralocorticoids are secreted from the adrenal cortex.
Aldosterone is the main mineralocorticoid in our body.
Aldosterone acts mainly at the renal tubules and stimulates the reabsorption of $Na^+$ and water and the excretion of $K^+$ and phosphate ions.
Mineralocorticoids are secreted from the adrenal cortex.
Aldosterone is the main mineralocorticoid in our body.
Aldosterone acts mainly at the renal tubules and stimulates the reabsorption of $Na^+$ and water and the excretion of $K^+$ and phosphate ions.
0 likesView Solution
37
BiologyMediumMCQAIIMS · 2012
Chasmogamy refers to the condition where
A
Flowers remain closed
B
Flowers are absent
C
Flowers are open
D
Flowers are gamopetalous
Solution
(C) Chasmogamous flowers are those that remain open,exposing their anthers and stigmas to the environment. This allows for cross-pollination or self-pollination. In certain bisexual plants like $Commelina$ and $Viola$,both chasmogamous and cleistogamous flowers (which never open throughout their life) are found.
0 likesView Solution
38
BiologyDifficultMCQAIIMS · 2012
Assertion: $Chasmogamous$ flowers require pollinating agents.
Reason: $Cleistogamous$ flowers do not expose their sex organs.
Reason: $Cleistogamous$ flowers do not expose their sex organs.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(A) The majority of angiosperms bear $Chasmogamous$ flowers,which means the flowers expose their mature anthers and stigma to the pollinating agents. Therefore,they require external agents for pollination.
$Cleistogamous$ flowers are those that do not open at all,meaning their anthers and stigma lie close to each other. When anthers dehisce in the closed flower buds,pollen grains come in contact with the stigma to effect pollination. Thus,they do not expose their sex organs and do not require pollinating agents.
Since both statements are correct and the reason explains why $Chasmogamous$ flowers (which do expose their sex organs) require agents while $Cleistogamous$ flowers do not,the correct option is $A$.
$Cleistogamous$ flowers are those that do not open at all,meaning their anthers and stigma lie close to each other. When anthers dehisce in the closed flower buds,pollen grains come in contact with the stigma to effect pollination. Thus,they do not expose their sex organs and do not require pollinating agents.
Since both statements are correct and the reason explains why $Chasmogamous$ flowers (which do expose their sex organs) require agents while $Cleistogamous$ flowers do not,the correct option is $A$.
0 likesView Solution
39
BiologyMediumMCQAIIMS · 2012
Which of the following organs is differentiated first during human embryonic development?
A
Heart
B
Skin
C
Brain
D
Neural tube
Solution
(A) In human beings,the first sign of the growing fetus may be noticed by listening to the heart sound carefully through the stethoscope.
After one month of pregnancy,the embryo's heart is formed.
By the end of the second month of pregnancy,the fetus develops limbs and digits.
By the end of $12$ weeks (the first trimester),most of the major organ systems,including the limbs and external genital organs,are well-developed.
After one month of pregnancy,the embryo's heart is formed.
By the end of the second month of pregnancy,the fetus develops limbs and digits.
By the end of $12$ weeks (the first trimester),most of the major organ systems,including the limbs and external genital organs,are well-developed.
0 likesView Solution
40
BiologyMediumMCQAIIMS · 2012
What is the function of Copper-$T$?
A
Checks mutation
B
Stops fertilization
C
Stops zygote formation
D
Stops obliteration of blastocoel
Solution
(B) Copper-$T$ is a copper-releasing intra-uterine device $(IUD)$. It increases the phagocytosis of sperms within the uterus,suppresses sperm motility,and reduces the fertilizing capacity of sperms,thereby preventing fertilization.
0 likesView Solution
41
BiologyMediumMCQAIIMS · 2012
Assertion: Cross of $F_1$ individual with recessive homozygous parent is test cross.
Reason: No recessive individuals are obtained in the monohybrid test cross.
Reason: No recessive individuals are obtained in the monohybrid test cross.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(C) test cross is defined as the cross of an $F_1$ hybrid with its homozygous recessive parent to determine the genotype of the $F_1$ individual.
In a monohybrid test cross (e.g.,$Tt \times tt$),the offspring are produced in a $1:1$ ratio,where $50\%$ of the individuals exhibit the dominant trait and $50\%$ exhibit the recessive trait.
Therefore,the Assertion is correct because it accurately defines a test cross.
However,the Reason is incorrect because recessive individuals are indeed obtained in a monohybrid test cross.
In a monohybrid test cross (e.g.,$Tt \times tt$),the offspring are produced in a $1:1$ ratio,where $50\%$ of the individuals exhibit the dominant trait and $50\%$ exhibit the recessive trait.
Therefore,the Assertion is correct because it accurately defines a test cross.
However,the Reason is incorrect because recessive individuals are indeed obtained in a monohybrid test cross.
0 likesView Solution
42
BiologyMediumMCQAIIMS · 2012
Which one of the following correctly represents the manner of replication of $DNA$?
A
B
C
D
Solution
(B) $DNA$ replication is semi-conservative and proceeds in the $5' \to 3'$ direction.
Because the two strands of the $DNA$ double helix are antiparallel,the replication fork moves in one direction,but the synthesis of new strands occurs differently on the two templates.
The leading strand is synthesized continuously in the $5' \to 3'$ direction towards the replication fork.
The lagging strand is synthesized discontinuously in the $5' \to 3'$ direction away from the replication fork,forming Okazaki fragments.
Option $B$ correctly depicts the antiparallel nature of the template strands ($5' \to 3'$ and $3' \to 5'$) and the resulting continuous and discontinuous synthesis of the new strands in the $5' \to 3'$ direction.
Because the two strands of the $DNA$ double helix are antiparallel,the replication fork moves in one direction,but the synthesis of new strands occurs differently on the two templates.
The leading strand is synthesized continuously in the $5' \to 3'$ direction towards the replication fork.
The lagging strand is synthesized discontinuously in the $5' \to 3'$ direction away from the replication fork,forming Okazaki fragments.
Option $B$ correctly depicts the antiparallel nature of the template strands ($5' \to 3'$ and $3' \to 5'$) and the resulting continuous and discontinuous synthesis of the new strands in the $5' \to 3'$ direction.
0 likesView Solution
43
BiologyMediumMCQAIIMS · 2012
Which of the following cannot be explained by Lamarckism?
A
Absence of limbs in snakes
B
Long neck of giraffe
C
Degeneration of visual apparatus in cave dwellers
D
Dull progeny of Nobel laureate
Solution
(D) According to Lamarck's theory of inheritance of acquired characters,traits developed during an organism's lifetime due to use and disuse of organs or environmental influence are passed on to the next generation.
Lamarckism suggests that if an individual acquires a trait (like intelligence or physical changes),it should be inherited by their offspring.
However,the observation that highly intelligent individuals (like Nobel laureates) can have offspring with average or lower intelligence contradicts the idea that acquired intellectual traits are inherited.
Therefore,the dull progeny of a Nobel laureate cannot be explained by Lamarckism.
Lamarckism suggests that if an individual acquires a trait (like intelligence or physical changes),it should be inherited by their offspring.
However,the observation that highly intelligent individuals (like Nobel laureates) can have offspring with average or lower intelligence contradicts the idea that acquired intellectual traits are inherited.
Therefore,the dull progeny of a Nobel laureate cannot be explained by Lamarckism.
0 likesView Solution
44
BiologyMediumMCQAIIMS · 2012
Assertion : Natural selection is the outcome of difference in survival and reproduction among individuals that show variation in one or more traits.
Reason : Adaptive forms of a given trait tend to become more common; less adaptive ones become less common or disappear.
Reason : Adaptive forms of a given trait tend to become more common; less adaptive ones become less common or disappear.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(A) Natural selection is the process by which individuals with favorable variations are better adapted to their environment,leading to higher survival and reproductive success.
This differential survival and reproduction result in the propagation of advantageous traits within a population.
Adaptive forms of a trait provide a survival advantage,allowing those individuals to reproduce more effectively,thus increasing the frequency of these traits in subsequent generations.
Conversely,less adaptive forms are selected against,leading to their decline or eventual disappearance from the population.
Therefore,the Reason correctly explains the mechanism behind the Assertion.
This differential survival and reproduction result in the propagation of advantageous traits within a population.
Adaptive forms of a trait provide a survival advantage,allowing those individuals to reproduce more effectively,thus increasing the frequency of these traits in subsequent generations.
Conversely,less adaptive forms are selected against,leading to their decline or eventual disappearance from the population.
Therefore,the Reason correctly explains the mechanism behind the Assertion.
0 likesView Solution
45
BiologyEasyMCQAIIMS · 2012
Match the following bacteria with the diseases:
| Column-$I$ | Column-$II$ |
| $A$. Treponema pallidum | $I$. Plague |
| $B$. Yersinia pestis | $II$. Anthrax |
| $C$. Bacillus anthracis | $III$. Syphilis |
| $D$. Vibrio | $IV$. Cholera |
A
$A-III, B-I, C-II, D-IV$
B
$A-IV, B-I, C-II, D-III$
C
$A-III, B-II, C-I, D-IV$
D
$A-I, B-III, C-II, D-IV$
Solution
(A) The correct matches are as follows:
$A$. Treponema pallidum causes Syphilis $(A-III)$.
$B$. Yersinia pestis causes Plague $(B-I)$.
$C$. Bacillus anthracis causes Anthrax $(C-II)$.
$D$. Vibrio (specifically Vibrio cholerae) causes Cholera $(D-IV)$.
Therefore, the correct sequence is $A-III, B-I, C-II, D-IV$.
$A$. Treponema pallidum causes Syphilis $(A-III)$.
$B$. Yersinia pestis causes Plague $(B-I)$.
$C$. Bacillus anthracis causes Anthrax $(C-II)$.
$D$. Vibrio (specifically Vibrio cholerae) causes Cholera $(D-IV)$.
Therefore, the correct sequence is $A-III, B-I, C-II, D-IV$.
0 likesView Solution
46
BiologyMediumMCQAIIMS · 2012
Assertion : Histamine is involved in allergic and inflammatory reactions.
Reason : Histamine is a vasodilator.
Reason : Histamine is a vasodilator.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(A) Histamine is a derivative of the amino acid $histidine$ produced by damaged cells of vertebrates.
When released,it acts as a vasodilator,meaning it dilates blood vessels (capillaries) and lowers blood pressure.
This physiological effect is a key component of the inflammatory response and allergic reactions.
Therefore,the Reason correctly explains why Histamine is involved in these reactions.
When released,it acts as a vasodilator,meaning it dilates blood vessels (capillaries) and lowers blood pressure.
This physiological effect is a key component of the inflammatory response and allergic reactions.
Therefore,the Reason correctly explains why Histamine is involved in these reactions.
0 likesView Solution
47
BiologyMediumMCQAIIMS · 2012
After $4$ $PCR$ cycles,how many $DNA$ molecules are formed from one $DNA$ template molecule?
A
$4$
B
$32$
C
$16$
D
$8$
Solution
(C) In the polymerase chain reaction $(PCR)$,the number of $DNA$ molecules produced after $n$ cycles is given by the formula $2^n$,where $n$ is the number of cycles.
Given that the number of cycles $n = 4$,the number of $DNA$ molecules formed will be $2^4 = 2 \times 2 \times 2 \times 2 = 16$.
Given that the number of cycles $n = 4$,the number of $DNA$ molecules formed will be $2^4 = 2 \times 2 \times 2 \times 2 = 16$.
0 likesView Solution
48
BiologyEasyMCQAIIMS · 2012
Golden rice is a transgenic crop of the future with the following improved trait:
A
High lysine (essential amino acid) content
B
Insect resistance
C
High protein content
D
High vitamin $A$ content
Solution
(D) Golden rice is a genetically modified variety of rice engineered to produce beta-carotene,which is a precursor of vitamin $A$. This modification helps in addressing vitamin $A$ deficiency in populations that rely heavily on rice as a staple food.
0 likesView Solution
49
BiologyMediumMCQAIIMS · 2012
The presence of flagellated protozoans in the gut of termites is an example of:
A
Symbiosis
B
Parasitism
C
Antibiosis
D
Commensalism
Solution
(A) The presence of flagellated protozoans in the gut of termites is an example of symbiosis (mutualism).
In this type of association,both partners are mutually benefited from each other.
Termites are dependent on the protozoa for the digestion of cellulose in their food,while the protozoa receive shelter and nutrients from the termite host.
In this type of association,both partners are mutually benefited from each other.
Termites are dependent on the protozoa for the digestion of cellulose in their food,while the protozoa receive shelter and nutrients from the termite host.
0 likesView Solution
50
BiologyMediumMCQAIIMS · 2012
Assertion: Thick cuticle is mostly present in disease-resistant plants.
Reason: Disease-causing agents cannot grow on the cuticle and cannot invade the cuticle.
Reason: Disease-causing agents cannot grow on the cuticle and cannot invade the cuticle.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(A) Many plants have evolved structural defenses to protect themselves against pathogens. $A$ thick cuticle acts as a physical barrier on the surface of leaves and stems. Because the cuticle is a waxy,non-living layer,disease-causing agents (pathogens) cannot easily grow on it or penetrate through it to reach the living tissues underneath. Therefore,a thick cuticle is a significant trait in disease-resistant plants,and the reason provided correctly explains this biological adaptation.
0 likesView Solution
51
BiologyMediumMCQAIIMS · 2012
Whale is
A
Primary producer
B
Carnivorous,secondary consumer
C
$A$ decomposer
D
Herbivorous
Solution
(B) Whales are carnivorous animals. They feed on primary consumers (such as krill or small fish) and occupy the third trophic level of the ecosystem.
0 likesView Solution
52
BiologyMediumMCQAIIMS · 2012
Assertion : Biotic community has higher position than population in ecological hierarchy.
Reason : Population of similar individuals remains isolated in the community.
Reason : Population of similar individuals remains isolated in the community.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(C) The ecological hierarchy is organized as: Individual $\rightarrow$ Population $\rightarrow$ Biotic Community $\rightarrow$ Ecosystem $\rightarrow$ Biome $\rightarrow$ Biosphere.
Therefore,the Assertion is correct because a biotic community consists of multiple populations of different species living together in a specific area,placing it at a higher level than a population.
The Reason is incorrect because populations within a biotic community are not isolated. They interact with each other through various ecological processes such as competition,predation,mutualism,and commensalism,forming a complex,interdependent network.
Therefore,the Assertion is correct because a biotic community consists of multiple populations of different species living together in a specific area,placing it at a higher level than a population.
The Reason is incorrect because populations within a biotic community are not isolated. They interact with each other through various ecological processes such as competition,predation,mutualism,and commensalism,forming a complex,interdependent network.
0 likesView Solution
53
BiologyMediumMCQAIIMS · 2012
If the Bengal tiger becomes extinct,
A
Hyenas and wolves will become scarce
B
The wild area will be safe for man and domestic animals
C
Its gene pool will be lost forever
D
The population of beautiful animals like deer will be stabilized
Solution
(C) If the Bengal tiger becomes extinct,its unique genetic information,known as the gene pool,will be lost forever. Biodiversity conservation is essential because species represent a unique evolutionary history. Methods for conservation include in-situ conservation (e.g.,National Parks,Wildlife Sanctuaries) and ex-situ conservation (e.g.,zoological parks,gene banks,and cryopreservation).
0 likesView Solution
54
BiologyMediumMCQAIIMS · 2012
Assertion: Tropical rain forests are disappearing fast from developing countries such as India.
Reason: No value is attached to these forests because these are poor in biodiversity.
Reason: No value is attached to these forests because these are poor in biodiversity.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
Solution
(C) Tropical rain forests are located in the equatorial regions where the annual rainfall exceeds $140\, cm$.
They are also called jungles and cover one-twelfth of the Earth's surface but contain more than half of the Earth's flora and fauna,meaning they are extremely rich in biodiversity.
Therefore,the Reason provided is factually incorrect because these forests are actually very rich in biodiversity,not poor.
Nowadays,these forests are disappearing rapidly due to excessive deforestation for domestic purposes like fuel,furniture,accommodation,clothing,resin,gum,etc.
They are also called jungles and cover one-twelfth of the Earth's surface but contain more than half of the Earth's flora and fauna,meaning they are extremely rich in biodiversity.
Therefore,the Reason provided is factually incorrect because these forests are actually very rich in biodiversity,not poor.
Nowadays,these forests are disappearing rapidly due to excessive deforestation for domestic purposes like fuel,furniture,accommodation,clothing,resin,gum,etc.
0 likesView Solution
55
BiologyMediumMCQAIIMS · 2012
In the environment,ozone is known for its
A
Harmful effects
B
Useful effects
C
Both $(A)$ and $(B)$
D
Inert nature
Solution
(C) In the environment,ozone is known for both its harmful and useful effects.
Ozone present in the stratosphere is useful because it acts as a shield and protects the Earth from harmful $UV$ rays.
Ozone present in the troposphere acts as a pollutant and has many deleterious effects on living organisms.
Ozone present in the stratosphere is useful because it acts as a shield and protects the Earth from harmful $UV$ rays.
Ozone present in the troposphere acts as a pollutant and has many deleterious effects on living organisms.
0 likesView Solution
Vedclass Products
For Students
Vedclass Test Series
Mock tests in real AIIMS style covering Biology with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D Biology papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Run live AIIMS mock exams with unlimited students, 360° analytics & white-label branding.
See DemoFrequently Asked Questions
How many Biology questions are in AIIMS 2012?
There are 55 Biology questions from the AIIMS 2012 paper on Vedclass, each with a detailed step-by-step solution in English.
Are AIIMS 2012 Biology solutions available in English?
Yes. All solutions on this page are in English. You can also switch to English or Hindi using the language buttons above the questions.
Can I practice AIIMS 2012 Biology as a timed test?
Yes. Use the Vedclass Test Series to attempt a full AIIMS mock test covering Biology with time limits and instant score analysis.
Can teachers create Biology papers from AIIMS previous year questions?
Yes. The Vedclass Exam Paper Generator lets teachers mix AIIMS Biology questions and generate Set A/B/C/D papers in minutes.
For Teachers & Institutes
Build a Custom Biology Paper
Pick AIIMS 2012 Biology questions, set difficulty, and generate Set A/B/C/D in 2 minutes.