BiologyQ101–138 of 228 questions
Page 3 of 3 · English
101
BiologyMediumMCQAIPMT · 1993
Anomalous secondary growth is observed in ..........
A
Dracaena
B
Ginger
C
Wheat
D
Sunflower
Solution
(A) Anomalous secondary growth refers to any deviation from the normal pattern of secondary growth observed in dicot stems.
In most monocots,secondary growth is absent. However,some monocots like $Dracaena$,$Yucca$,and $Aloe$ exhibit anomalous secondary growth.
This occurs due to the formation of a secondary cambium in the cortex,which produces vascular bundles and parenchyma,leading to an increase in the girth of the stem.
Therefore,$Dracaena$ is the correct example among the given options.
In most monocots,secondary growth is absent. However,some monocots like $Dracaena$,$Yucca$,and $Aloe$ exhibit anomalous secondary growth.
This occurs due to the formation of a secondary cambium in the cortex,which produces vascular bundles and parenchyma,leading to an increase in the girth of the stem.
Therefore,$Dracaena$ is the correct example among the given options.
0 likesView Solution
102
BiologyMediumMCQAIPMT · 1993
The formation of endochondral bone involves:
A
Deposition of bone matrix by osteoblasts and resorption by chondroclasts.
B
Deposition of bone matrix by osteoclasts and resorption by chondroblasts.
C
Only deposition of bone matrix by osteoclasts.
D
Only deposition of bone matrix by osteoblasts.
Solution
(A) Endochondral ossification is the process by which cartilage is replaced by bone tissue.
$1$. During this process,cartilage models are formed by chondrocytes.
$2$. Osteoblasts (bone-forming cells) deposit the bone matrix on the cartilage scaffold.
$3$. Chondroclasts (cartilage-resorbing cells) are responsible for the resorption or breakdown of the cartilage matrix to allow for the replacement by bone tissue.
$4$. Therefore,the process involves the deposition of bone matrix by osteoblasts and the resorption of cartilage by chondroclasts.
$1$. During this process,cartilage models are formed by chondrocytes.
$2$. Osteoblasts (bone-forming cells) deposit the bone matrix on the cartilage scaffold.
$3$. Chondroclasts (cartilage-resorbing cells) are responsible for the resorption or breakdown of the cartilage matrix to allow for the replacement by bone tissue.
$4$. Therefore,the process involves the deposition of bone matrix by osteoblasts and the resorption of cartilage by chondroclasts.
0 likesView Solution
103
BiologyMediumMCQAIPMT · 1993
Vitamin $K$ is required for:
A
Synthesis of prothrombin
B
Conversion of fibrinogen to fibrin
C
Conversion of prothrombin to thrombin
D
Formation of thromboplastin
Solution
(A) Vitamin $K$ is essential for the synthesis of clotting factors in the liver,specifically prothrombin (Factor $II$),Factor $VII$,Factor $IX$,and Factor $X$. Prothrombin is an inactive precursor protein that is synthesized in the liver in the presence of Vitamin $K$. Once synthesized,it is released into the blood,where it later participates in the coagulation cascade to be converted into thrombin. Therefore,the primary role of Vitamin $K$ is in the synthesis of prothrombin.
0 likesView Solution
104
BiologyMediumMCQAIPMT · 1993
The genophore/bacterial genome or nucleoid is made up of:
A
Histones and non-histones
B
$RNA$ and histones
C
$A$ single double-stranded $DNA$
D
Single-stranded $DNA$
Solution
(C) The bacterial genome,often referred to as the genophore or nucleoid,consists of a single,circular,double-stranded $DNA$ molecule. Unlike eukaryotic cells,prokaryotic cells lack a defined nucleus and do not contain histone proteins to package their $DNA$. Therefore,the correct description is a single double-stranded $DNA$ molecule.
0 likesView Solution
105
BiologyMediumMCQAIPMT · 1993
The cell membrane,which is a component of the endomembrane system,is primarily composed of which biochemicals?
A
Proteins
B
Lipids
C
Proteins and lipids
D
Glycoproteins and glycolipids
Solution
(C) The cell membrane (plasma membrane) is primarily composed of lipids and proteins.
According to the fluid mosaic model,the membrane consists of a lipid bilayer in which protein molecules are embedded.
Lipids are arranged within the membrane with the polar head towards the outer sides and the hydrophobic tails towards the inner part.
Therefore,the correct answer is proteins and lipids.
According to the fluid mosaic model,the membrane consists of a lipid bilayer in which protein molecules are embedded.
Lipids are arranged within the membrane with the polar head towards the outer sides and the hydrophobic tails towards the inner part.
Therefore,the correct answer is proteins and lipids.
0 likesView Solution
106
BiologyMediumMCQAIPMT · 1993
In which of the following are Golgi bodies absent?
A
Higher plants
B
Yeast
C
Bacteria and Blue-green algae
D
None of these
Solution
(C) Golgi bodies are membrane-bound organelles found in eukaryotic cells.
Prokaryotic cells,such as $Bacteria$ and $Blue-green$ $algae$ $(Cyanobacteria)$,lack membrane-bound organelles,including the Golgi apparatus.
Therefore,Golgi bodies are absent in bacteria and blue-green algae.
Prokaryotic cells,such as $Bacteria$ and $Blue-green$ $algae$ $(Cyanobacteria)$,lack membrane-bound organelles,including the Golgi apparatus.
Therefore,Golgi bodies are absent in bacteria and blue-green algae.
0 likesView Solution
107
BiologyEasyMCQAIPMT · 1993
The names of $Schleiden$ and $Schwann$ are associated with which of the following?
A
Protoplasm is the physical basis of life.
B
Cell Theory
C
Theory of linear cell structure
D
Regulation of cell functions by the nucleus
Solution
(B) $Matthias$ $Schleiden$ (a German botanist) in $1838$ and $Theodor$ $Schwann$ (a British zoologist) in $1839$ independently formulated the $Cell$ $Theory$.
$Schleiden$ observed that all plants are composed of cells,and $Schwann$ reported that animal cells have a thin outer layer (plasma membrane) and plant cells have a cell wall.
Together,they proposed that the bodies of plants and animals are composed of cells and products of cells.
Therefore,their names are associated with the $Cell$ $Theory$.
$Schleiden$ observed that all plants are composed of cells,and $Schwann$ reported that animal cells have a thin outer layer (plasma membrane) and plant cells have a cell wall.
Together,they proposed that the bodies of plants and animals are composed of cells and products of cells.
Therefore,their names are associated with the $Cell$ $Theory$.
0 likesView Solution
108
BiologyMediumMCQAIPMT · 1993
According to the Cell Theory,which statement is true regarding cell structure?
A
It is adapted due to the discovery of sub-cellular structures like chloroplasts and mitochondria.
B
All living organisms' cells have the capacity for reproduction,which is the basis of the modern Cell Theory.
C
Cell Theory is not true because all organisms cannot form cellular structures (e.g.,viruses).
D
Cell Theory means that all cells of all organisms have the capacity for reproduction or not.
Solution
(A) The modern Cell Theory (Cell Principle) states that all living organisms are composed of cells and products of cells. Furthermore,all cells arise from pre-existing cells ($Omnis$ $cellula-e$ $cellula$). The discovery of organelles like mitochondria and chloroplasts,which contain their own $DNA$ and can replicate independently,supports the idea that cells are the fundamental units of life and that they possess the machinery for reproduction and self-maintenance. Thus,the theory has been refined over time to include these observations.
0 likesView Solution
109
BiologyMediumMCQAIPMT · 1993
What is the membrane-bound sac containing hydrolytic enzymes used for the intracellular digestion of macromolecules called?
A
Endoplasmic reticulum
B
Nucleosome
C
Lysosome
D
Phagosome
Solution
(C) Lysosomes are membrane-bound vesicular structures formed by the process of packaging in the Golgi apparatus.
These organelles are rich in hydrolytic enzymes (hydrolases like lipases,proteases,and carbohydrases) that are optimally active at an acidic $pH$.
These enzymes are capable of digesting carbohydrates,proteins,lipids,and nucleic acids,making them essential for intracellular digestion and the removal of worn-out cell organelles.
These organelles are rich in hydrolytic enzymes (hydrolases like lipases,proteases,and carbohydrases) that are optimally active at an acidic $pH$.
These enzymes are capable of digesting carbohydrates,proteins,lipids,and nucleic acids,making them essential for intracellular digestion and the removal of worn-out cell organelles.
0 likesView Solution
110
BiologyMediumMCQAIPMT · 1993
In plant cells,peroxisomes are associated with which of the following?
A
Photorespiration
B
Phototropism
C
Photoperiodism
D
Photosynthesis
Solution
(A) In plant cells,peroxisomes (specifically leaf peroxisomes) play a crucial role in the process of $Photorespiration$ (also known as the $C_2$ cycle). During this process,they work in coordination with chloroplasts and mitochondria to metabolize glycolate,which is a byproduct of the oxygenase activity of $RuBisCO$.
0 likesView Solution
111
BiologyMediumMCQAIPMT · 1993
Glucose is reabsorbed from the glomerular filtrate by ......... .
A
Active transport
B
Passive transport
C
Osmosis
D
Diffusion
Solution
(A) In the nephron,the glomerular filtrate contains essential substances like glucose,amino acids,and electrolytes.
Glucose is reabsorbed from the proximal convoluted tubule $(PCT)$ of the nephron back into the blood.
This process occurs against the concentration gradient,which requires energy in the form of $ATP$.
Therefore,the reabsorption of glucose is an example of active transport.
Glucose is reabsorbed from the proximal convoluted tubule $(PCT)$ of the nephron back into the blood.
This process occurs against the concentration gradient,which requires energy in the form of $ATP$.
Therefore,the reabsorption of glucose is an example of active transport.
0 likesView Solution
112
BiologyMediumMCQAIPMT · 1993
Long bones function as ........
A
Support
B
Support,synthesis of red blood cells and white blood cells
C
Support and erythropoiesis
D
Erythropoiesis
Solution
(B) Long bones serve two primary functions in the human body:
$1$. Support: They provide structural framework and support for the body,allowing for posture and movement.
$2$. Erythropoiesis: The bone marrow located within the cavity of long bones is the primary site for the production of red blood cells (erythropoiesis),as well as white blood cells and platelets.
$1$. Support: They provide structural framework and support for the body,allowing for posture and movement.
$2$. Erythropoiesis: The bone marrow located within the cavity of long bones is the primary site for the production of red blood cells (erythropoiesis),as well as white blood cells and platelets.
0 likesView Solution
113
BiologyEasyMCQAIPMT · 1993
The amount of light entering the eye is regulated by the:
A
Pupil
B
Aperture
C
Cornea
D
Lens
Solution
(A) The $Pupil$ is a circular aperture in the center of the $Iris$. The $Iris$ contains muscles that contract or relax to change the size of the $Pupil$,thereby regulating the amount of light that enters the eye. When light intensity is high,the $Pupil$ constricts,and when light intensity is low,the $Pupil$ dilates.
0 likesView Solution
114
BiologyMediumMCQAIPMT · 1993
The $CNS$ is primarily composed of:
A
Motor neurons and sensory neurons
B
Sensory neurons and interneurons
C
Interneurons
D
Motor neurons and interneurons
Solution
(C) The Central Nervous System $(CNS)$ consists of the brain and the spinal cord.
Within the $CNS$,the primary functional units responsible for processing information and connecting sensory and motor pathways are interneurons (also known as association neurons).
While the $CNS$ receives input from sensory neurons and sends output via motor neurons,the actual structure of the $CNS$ itself is predominantly composed of interneurons that integrate these signals.
Within the $CNS$,the primary functional units responsible for processing information and connecting sensory and motor pathways are interneurons (also known as association neurons).
While the $CNS$ receives input from sensory neurons and sends output via motor neurons,the actual structure of the $CNS$ itself is predominantly composed of interneurons that integrate these signals.
0 likesView Solution
115
BiologyEasyMCQAIPMT · 1993
The function of the pupil is:
A
To move the lens forward and backward.
B
To regulate the amount of light entering the eye.
C
To induce movement of the eyelids.
D
To change the size of the eyeball.
Solution
(B) The pupil is the aperture located in the center of the iris of the eye. Its primary function is to regulate the amount of light that enters the eye. In bright light,the iris muscles contract to make the pupil smaller,reducing light entry. In dim light,the iris muscles relax to make the pupil larger,allowing more light to enter.
0 likesView Solution
116
BiologyEasyMCQAIPMT · 1993
The area of the retina that is most sensitive to light is the:
A
Optic disc
B
Sclera
C
Macula lutea
D
Fovea centralis
Solution
(D) The $Fovea$ $centralis$ is a small, central pit in the $Macula$ $lutea$ of the retina.
It contains the highest density of cone cells and is responsible for sharp, detailed central vision.
Because it lacks rod cells and has the highest concentration of cones, it is the area of the retina that is most sensitive to light and provides the highest visual acuity.
It contains the highest density of cone cells and is responsible for sharp, detailed central vision.
Because it lacks rod cells and has the highest concentration of cones, it is the area of the retina that is most sensitive to light and provides the highest visual acuity.
0 likesView Solution
117
BiologyMediumMCQAIPMT · 1993
What does an enzyme do?
A
Decreases the reaction time.
B
Increases the reaction time.
C
Increases the activation energy.
D
Decreases the activation energy.
Solution
(D) Enzymes are biological catalysts that speed up chemical reactions in living organisms.
They function by lowering the activation energy $(E_a)$ required for a reaction to proceed.
By reducing the energy barrier,more substrate molecules can reach the transition state at a given temperature,thereby increasing the rate of the reaction.
They function by lowering the activation energy $(E_a)$ required for a reaction to proceed.
By reducing the energy barrier,more substrate molecules can reach the transition state at a given temperature,thereby increasing the rate of the reaction.
0 likesView Solution
118
BiologyMediumMCQAIPMT · 1993
Which of the following statements is incorrect regarding nucleic acids?
A
Some viruses contain single-stranded $DNA$.
B
$RNA$ sometimes exists as a double-stranded molecule.
C
In $\beta-DNA$,one turn has a length of $45 \ \mathring{A}$.
D
$Z-DNA$ has $12$ base pairs per turn.
Solution
(C) In $\beta-DNA$ (the standard Watson-Crick model),one full turn of the helix is $34 \ \mathring{A}$ long,not $45 \ \mathring{A}$.
Therefore,the statement in option $C$ is incorrect.
- Some viruses (e.g.,$\phi X174$) contain single-stranded $DNA$.
- $RNA$ can be double-stranded in certain viruses (e.g.,Reovirus).
- $Z-DNA$ is a left-handed helix with $12$ base pairs per turn.
Therefore,the statement in option $C$ is incorrect.
- Some viruses (e.g.,$\phi X174$) contain single-stranded $DNA$.
- $RNA$ can be double-stranded in certain viruses (e.g.,Reovirus).
- $Z-DNA$ is a left-handed helix with $12$ base pairs per turn.
0 likesView Solution
119
BiologyMediumMCQAIPMT · 1993
Balbiani rings (puffs) are sites of:
A
$DNA$ replication
B
$RNA$ and protein synthesis
C
Synthesis of polysaccharides
D
Synthesis of lipids
Solution
(B) Balbiani rings,also known as chromosomal puffs,are large,localized swellings found on polytene chromosomes in certain insect tissues (e.g.,salivary glands of Chironomus larvae).
These structures represent regions of intense gene activity where the chromatin is decondensed.
This decondensation allows for high levels of transcription,leading to the synthesis of large amounts of $mRNA$ (messenger $RNA$).
Consequently,these $mRNA$ molecules are subsequently used for protein synthesis in the cytoplasm.
Therefore,Balbiani rings are primarily sites of active $RNA$ transcription and subsequent protein synthesis.
These structures represent regions of intense gene activity where the chromatin is decondensed.
This decondensation allows for high levels of transcription,leading to the synthesis of large amounts of $mRNA$ (messenger $RNA$).
Consequently,these $mRNA$ molecules are subsequently used for protein synthesis in the cytoplasm.
Therefore,Balbiani rings are primarily sites of active $RNA$ transcription and subsequent protein synthesis.
0 likesView Solution
120
BiologyMediumMCQAIPMT · 1993
What does Meiosis-$II$ represent?
A
Separation of sex chromosomes
B
Synthesis of $DNA$ and centromeres
C
Separation of homologous chromosomes
D
Separation of chromatids
Solution
(D) Meiosis-$II$ is known as an equational division,similar to mitosis.
During Meiosis-$II$,the sister chromatids of each chromosome separate at the centromere.
This process results in the formation of four haploid daughter cells from the two haploid cells produced in Meiosis-$I$.
Therefore,the primary event in Meiosis-$II$ is the separation of chromatids.
During Meiosis-$II$,the sister chromatids of each chromosome separate at the centromere.
This process results in the formation of four haploid daughter cells from the two haploid cells produced in Meiosis-$I$.
Therefore,the primary event in Meiosis-$II$ is the separation of chromatids.
0 likesView Solution
121
BiologyMediumMCQAIPMT · 1993
Polytene chromosomes in salivary glands are formed by the pairing of:
A
Absent
B
Sometimes
C
Non-homologous chromosomes
D
Homologous chromosomes
Solution
(D) Polytene chromosomes are giant chromosomes found in the salivary glands of Drosophila larvae and some other Dipteran insects.
They are formed through a process called endoreduplication,where the $DNA$ undergoes multiple rounds of replication without cell division.
These replicated chromatids remain attached to each other side-by-side,a process known as somatic pairing.
This pairing occurs specifically between homologous chromosomes,resulting in a bundle of many parallel chromatids.
They are formed through a process called endoreduplication,where the $DNA$ undergoes multiple rounds of replication without cell division.
These replicated chromatids remain attached to each other side-by-side,a process known as somatic pairing.
This pairing occurs specifically between homologous chromosomes,resulting in a bundle of many parallel chromatids.
0 likesView Solution
122
BiologyMediumMCQAIPMT · 1993
Which surface is better adapted for gas exchange in plant leaves?
A
Lower surface trichomes
B
Multilayered epidermis
C
Waxy cuticle
D
Stomata on the lower surface away from direct sunlight
Solution
(D) In most dicotyledonous plants,the lower surface of the leaf is better adapted for gas exchange because it contains a higher density of stomata. Placing stomata on the lower surface helps in reducing the rate of transpiration by keeping them away from direct sunlight,while still allowing efficient $CO_2$ uptake and $O_2$ release for photosynthesis.
0 likesView Solution
123
BiologyEasyMCQAIPMT · 1993
In the Calvin cycle of $C_3$ plants,which molecule acts as the primary $CO_2$ acceptor?
A
Phosphoenolpyruvate $(PEP)$
B
Ribulose $1,5$-bisphosphate $(RuBP)$
C
Phosphoglyceric acid $(PGA)$
D
Ribulose monophosphate $(RMP)$
Solution
(B) In the Calvin cycle,which occurs in the stroma of chloroplasts,the primary $CO_2$ acceptor is a $5$-carbon ketose sugar called Ribulose $1,5$-bisphosphate $(RuBP)$.
This reaction is catalyzed by the enzyme Ribulose bisphosphate carboxylase-oxygenase $(RuBisCO)$.
$PEP$ is the primary $CO_2$ acceptor in $C_4$ plants,while $PGA$ is the first stable product of the Calvin cycle.
This reaction is catalyzed by the enzyme Ribulose bisphosphate carboxylase-oxygenase $(RuBisCO)$.
$PEP$ is the primary $CO_2$ acceptor in $C_4$ plants,while $PGA$ is the first stable product of the Calvin cycle.
0 likesView Solution
124
BiologyMediumMCQAIPMT · 1993
If a photosynthetic plant releases $18$ $O_2$ more than usual,what must the plant have received?
A
$O_3$
B
$H_2^{18}O$
C
$C^{18}O_2$
D
$C_6H_{12}^{18}O_6$ along with $18$ $O_2$
Solution
(B) The oxygen released during photosynthesis comes from the photolysis of water $(H_2O)$.
According to the experiments conducted by Ruben,Hassid,and Kamen using the heavy isotope of oxygen $(^{18}O)$,it was proven that the $O_2$ evolved during photosynthesis is derived from water and not from carbon dioxide $(CO_2)$.
Therefore,if a plant releases $O_2$ containing the heavy isotope $^{18}O$,it must have been provided with water labeled with the heavy isotope,i.e.,$H_2^{18}O$.
According to the experiments conducted by Ruben,Hassid,and Kamen using the heavy isotope of oxygen $(^{18}O)$,it was proven that the $O_2$ evolved during photosynthesis is derived from water and not from carbon dioxide $(CO_2)$.
Therefore,if a plant releases $O_2$ containing the heavy isotope $^{18}O$,it must have been provided with water labeled with the heavy isotope,i.e.,$H_2^{18}O$.
0 likesView Solution
125
BiologyMediumMCQAIPMT · 1993
Out of $38$ $ATP$ molecules produced per glucose,$32$ $ATP$ molecules are generated from $NADH/FADH_2$ in which of the following processes?
A
Respiratory chain
B
Krebs cycle
C
Oxidative decarboxylation
D
$EMP$ pathway
Solution
(A) In aerobic respiration,the complete oxidation of one glucose molecule yields $38$ $ATP$ molecules.
Out of these,$4$ $ATP$ are produced via substrate-level phosphorylation (two from glycolysis and two from the Krebs cycle).
The remaining $32$ $ATP$ molecules are generated through the Electron Transport System $(ETS)$ or Respiratory chain,where $NADH$ and $FADH_2$ are oxidized to produce $ATP$ via oxidative phosphorylation.
Out of these,$4$ $ATP$ are produced via substrate-level phosphorylation (two from glycolysis and two from the Krebs cycle).
The remaining $32$ $ATP$ molecules are generated through the Electron Transport System $(ETS)$ or Respiratory chain,where $NADH$ and $FADH_2$ are oxidized to produce $ATP$ via oxidative phosphorylation.
0 likesView Solution
126
BiologyMediumMCQAIPMT · 1993
What is the final product of the Citric Acid Cycle / Krebs Cycle?
A
Citric acid
B
Lactic acid
C
Pyruvic acid
D
$CO_2 + H_2O$
Solution
(D) The Citric Acid Cycle,also known as the Krebs Cycle,is a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates,fats,and proteins into $CO_2$ and chemical energy in the form of $ATP$.
In this cycle,the acetyl group is completely oxidized to $CO_2$,and the electrons are transferred to $NAD^+$ and $FAD$ to form $NADH$ and $FADH_2$.
Therefore,the final products of the complete aerobic respiration process,including the Krebs cycle and the electron transport chain,are $CO_2$ and $H_2O$.
In this cycle,the acetyl group is completely oxidized to $CO_2$,and the electrons are transferred to $NAD^+$ and $FAD$ to form $NADH$ and $FADH_2$.
Therefore,the final products of the complete aerobic respiration process,including the Krebs cycle and the electron transport chain,are $CO_2$ and $H_2O$.
0 likesView Solution
127
BiologyMediumMCQAIPMT · 1993
Life without air is ........
A
Reductive.
B
Free from oxidative injury.
C
Impossible.
D
Anaerobic.
Solution
(C) Life as we know it on Earth is primarily dependent on aerobic respiration,which requires $O_2$ to efficiently produce $ATP$ through the electron transport chain. Without air (specifically $O_2$),the complex metabolic processes required to sustain multicellular life cannot occur. While some microorganisms are obligate anaerobes,for the vast majority of living organisms,life without air is impossible.
0 likesView Solution
128
BiologyEasyMCQAIPMT · 1993
Abscisic acid $(ABA)$ regulates which of the following?
A
Cell division
B
Leaf abscission and dormancy
C
Shoot elongation
D
Cell elongation and cell wall formation
Solution
(B) Abscisic acid $(ABA)$ is a plant growth inhibitor.
It plays a crucial role in the abscission of leaves and fruits.
It also induces dormancy in seeds and buds,which helps plants survive unfavorable environmental conditions.
Therefore,$ABA$ is primarily associated with the regulation of leaf abscission and dormancy.
It plays a crucial role in the abscission of leaves and fruits.
It also induces dormancy in seeds and buds,which helps plants survive unfavorable environmental conditions.
Therefore,$ABA$ is primarily associated with the regulation of leaf abscission and dormancy.
0 likesView Solution
129
BiologyMediumMCQAIPMT · 1993
The clinostat is used for the study of which of the following?
A
Osmosis
B
Growth movements
C
Photosynthesis
D
Respiration
Solution
(B) $clinostat$ is a device used to eliminate the effect of gravity on plant growth.
It consists of a rotating shaft that slowly turns a plant,ensuring that the gravitational force is applied equally from all directions.
This helps in studying $geotropism$ (or $gravitropism$) and other growth movements by neutralizing the directional influence of gravity.
It consists of a rotating shaft that slowly turns a plant,ensuring that the gravitational force is applied equally from all directions.
This helps in studying $geotropism$ (or $gravitropism$) and other growth movements by neutralizing the directional influence of gravity.
0 likesView Solution
130
BiologyMediumMCQAIPMT · 1993
What is the result of removing the apical bud?
A
$A$ new apical bud is formed
B
The main stem elongates
C
The plant dies
D
Lateral branches are formed
Solution
(D) The apical bud produces the hormone auxin,which inhibits the growth of lateral buds,a phenomenon known as apical dominance. When the apical bud is removed,the source of auxin is eliminated. This releases the lateral buds from inhibition,allowing them to grow and develop into lateral branches.
0 likesView Solution
131
BiologyMediumMCQAIPMT · 1993
Which of the following plant growth regulators is known as a "Stress hormone"?
A
Abscisic acid
B
Ethylene
C
$GA_3$
D
Indole-3-acetic acid
Solution
(A) Abscisic acid $(ABA)$ is known as the "Stress hormone" in plants.
It plays a crucial role in helping plants cope with various environmental stresses, such as drought, salinity, and extreme temperatures.
$ABA$ promotes the closure of stomata to prevent water loss during water-deficit conditions, thereby protecting the plant from desiccation.
It plays a crucial role in helping plants cope with various environmental stresses, such as drought, salinity, and extreme temperatures.
$ABA$ promotes the closure of stomata to prevent water loss during water-deficit conditions, thereby protecting the plant from desiccation.
0 likesView Solution
132
BiologyMediumMCQAIPMT · 1993
The secretion of gastric juice is inhibited by .........
A
Gastrin
B
Pancreozymin
C
Cholecystokinin
D
Enterogastrone
Solution
(D) The secretion of gastric juice is primarily regulated by both neural and hormonal mechanisms.
$1$. Gastrin is a hormone that stimulates the secretion of gastric juice.
$2$. Enterogastrone (also known as Gastric Inhibitory Peptide or $GIP$) is a hormone secreted by the duodenal mucosa when fatty acids and acidic chyme enter the duodenum.
$3$. This hormone acts to inhibit the secretion of gastric juice and reduces gastric motility,allowing more time for digestion in the small intestine.
Therefore,the correct answer is $D$.
$1$. Gastrin is a hormone that stimulates the secretion of gastric juice.
$2$. Enterogastrone (also known as Gastric Inhibitory Peptide or $GIP$) is a hormone secreted by the duodenal mucosa when fatty acids and acidic chyme enter the duodenum.
$3$. This hormone acts to inhibit the secretion of gastric juice and reduces gastric motility,allowing more time for digestion in the small intestine.
Therefore,the correct answer is $D$.
0 likesView Solution
133
BiologyMediumMCQAIPMT · 1993
Which of the following pairs shows symptoms like swollen lips,thick pigmented skin on the hands,and irritability?
A
Thiamine - Beriberi
B
Protein - Kwashiorkor
C
Nicotinamide - Pellagra
D
Iodine - Goiter
Solution
(C) Pellagra is a deficiency disease caused by a lack of $Vitamin B_3$ (Niacin or Nicotinamide).
Symptoms of Pellagra are often described by the '$4Ds$': Dermatitis (thick,pigmented skin),Diarrhea,Dementia (irritability,confusion),and Death.
Swollen lips (cheilosis) and glossitis are also common clinical features associated with this deficiency.
Therefore,the correct pair is Nicotinamide - Pellagra.
Symptoms of Pellagra are often described by the '$4Ds$': Dermatitis (thick,pigmented skin),Diarrhea,Dementia (irritability,confusion),and Death.
Swollen lips (cheilosis) and glossitis are also common clinical features associated with this deficiency.
Therefore,the correct pair is Nicotinamide - Pellagra.
0 likesView Solution
134
BiologyMediumMCQAIPMT · 1993
Most of the fat digestion occurs in the ....... .
A
Rectum
B
Stomach
C
Duodenum
D
Small intestine
Solution
(D) The digestion of fats begins in the stomach to a very small extent,but the majority of fat digestion occurs in the $Small \ intestine$.
Specifically,the $Duodenum$ (the first part of the small intestine) receives bile from the liver,which emulsifies fats,and pancreatic lipase,which breaks down the emulsified fats into fatty acids and glycerol.
Therefore,the small intestine is the primary site for fat digestion.
Specifically,the $Duodenum$ (the first part of the small intestine) receives bile from the liver,which emulsifies fats,and pancreatic lipase,which breaks down the emulsified fats into fatty acids and glycerol.
Therefore,the small intestine is the primary site for fat digestion.
0 likesView Solution
135
BiologyMediumMCQAIPMT · 1993
The transport of carbon dioxide from tissues to the respiratory surface occurs primarily through ..........
A
Plasma and Red Blood Cells
B
Plasma
C
Red Blood Cells
D
Red Blood Cells and White Blood Cells
Solution
(A) Carbon dioxide $(CO_2)$ is transported from tissues to the lungs in three forms:
$1$. As dissolved gas in plasma $(7\%)$.
$2$. As bicarbonate ions $(HCO_3^-)$ in plasma $(70\%)$.
$3$. As carbaminohemoglobin in red blood cells $(23\%)$.
Since both plasma and red blood cells are involved in the transport of $CO_2$,the correct option is $A$.
$1$. As dissolved gas in plasma $(7\%)$.
$2$. As bicarbonate ions $(HCO_3^-)$ in plasma $(70\%)$.
$3$. As carbaminohemoglobin in red blood cells $(23\%)$.
Since both plasma and red blood cells are involved in the transport of $CO_2$,the correct option is $A$.
0 likesView Solution
136
BiologyMediumMCQAIPMT · 1993
The wall of blood capillaries is composed of:
A
Hemocytes
B
Parietal cells
C
Endothelial cells
D
Oxyntic cells
Solution
(C) The wall of blood capillaries is extremely thin and is composed of a single layer of squamous epithelial cells,which are known as $Endothelial$ $cells$. These cells rest on a basement membrane. This structure allows for the efficient exchange of gases,nutrients,and waste products between the blood and the surrounding tissues.
0 likesView Solution
137
BiologyEasyMCQAIPMT · 1993
Cells produced in the bone marrow include .......
A
$RBCs$
B
$RBCs$ and $WBCs$
C
$WBCs$
D
Lymphocytes
Solution
(B) The bone marrow is the primary lymphoid organ where all blood cells,including $RBCs$ (erythrocytes),$WBCs$ (leukocytes),and platelets,are produced through the process of hematopoiesis. Therefore,the bone marrow produces both $RBCs$ and $WBCs$.
0 likesView Solution
138
BiologyEasyMCQAIPMT · 1993
Which type of soil is most suitable for plant growth?
A
Clay
B
Loamy
C
Sandy
D
Gravelly
Solution
(B) Loamy soil is considered the most suitable for plant growth because it contains a balanced mixture of sand,silt,and clay. This composition provides the ideal balance of water retention,aeration,and nutrient availability,which are essential for healthy root development and plant growth.
0 likesView Solution
Vedclass Products
For Students
Vedclass Test Series
Mock tests in real AIPMT 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 AIPMT mock exams with unlimited students, 360° analytics & white-label branding.
See DemoFrequently Asked Questions
How many Biology questions are in AIPMT 1993?
There are 228 Biology questions from the AIPMT 1993 paper on Vedclass, each with a detailed step-by-step solution in English.
Are AIPMT 1993 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 AIPMT 1993 Biology as a timed test?
Yes. Use the Vedclass Test Series to attempt a full AIPMT mock test covering Biology with time limits and instant score analysis.
Can teachers create Biology papers from AIPMT previous year questions?
Yes. The Vedclass Exam Paper Generator lets teachers mix AIPMT Biology questions and generate Set A/B/C/D papers in minutes.
For Teachers & Institutes
Build a Custom Biology Paper
Pick AIPMT 1993 Biology questions, set difficulty, and generate Set A/B/C/D in 2 minutes.