BiologyQ101–109 of 171 questions
Page 3 of 3 · English
101
BiologyMediumMCQAIPMT · 1990
Phototropism and geotropism are associated with which of the following?
A
Gibberellin
B
Enzymes
C
Auxin
D
Cytokinin
Solution
(C) Phototropism (growth towards light) and geotropism (growth in response to gravity) are primarily regulated by the plant hormone $Auxin$.
$Auxin$ is synthesized at the shoot tips and root tips.
It promotes cell elongation in the shoot and inhibits it in the root,leading to differential growth that results in the bending of plants towards light or in response to gravity.
$Auxin$ is synthesized at the shoot tips and root tips.
It promotes cell elongation in the shoot and inhibits it in the root,leading to differential growth that results in the bending of plants towards light or in response to gravity.
0 likesView Solution
102
BiologyMediumMCQAIPMT · 1990
Which of the following is $NOT$ an effect of $Auxin$?
A
Bending of the shoot towards the direction of light.
B
Bending of the root towards the direction of gravity.
C
Bending of the leaf towards the direction of fragrance.
D
Bending of the sunflower apex towards the direction of the sun.
Solution
(C) $1$. $Auxin$ is a plant hormone responsible for phototropism and geotropism.
$2$. The bending of shoots towards light (phototropism) and roots towards gravity (geotropism) are classic responses mediated by $Auxin$ distribution.
$3$. The movement of the sunflower apex towards the sun (heliotropism) is also regulated by $Auxin$ gradients.
$4$. There is no biological evidence or physiological mechanism where $Auxin$ causes a leaf to bend towards a 'fragrance'. Therefore,option $C$ is not an effect of $Auxin$.
$2$. The bending of shoots towards light (phototropism) and roots towards gravity (geotropism) are classic responses mediated by $Auxin$ distribution.
$3$. The movement of the sunflower apex towards the sun (heliotropism) is also regulated by $Auxin$ gradients.
$4$. There is no biological evidence or physiological mechanism where $Auxin$ causes a leaf to bend towards a 'fragrance'. Therefore,option $C$ is not an effect of $Auxin$.
0 likesView Solution
103
BiologyMediumMCQAIPMT · 1990
Emulsification of fats does not occur in the absence of .....
A
Lipase
B
Bile pigments
C
Bile salts
D
Pancreatic juice
Solution
(C) Emulsification is the process of breaking down large fat globules into smaller droplets,which increases the surface area for the action of enzymes. This process is primarily facilitated by bile salts (such as sodium glycocholate and sodium taurocholate) present in the bile juice. In the absence of bile salts,fats cannot be emulsified,which significantly hinders their digestion. Therefore,the correct answer is $C$.
0 likesView Solution
104
BiologyEasyMCQAIPMT · 1990
In humans,zymogen or chief cells are found in the ........
A
Cardiac part of the stomach
B
Pyloric part of the stomach
C
Duodenum
D
Fundic part of the stomach
Solution
(D) Zymogen cells,also known as chief cells or peptic cells,are primarily located in the gastric glands of the fundic region of the stomach.
These cells are responsible for the secretion of proenzymes such as pepsinogen and prorennin,which are essential for protein digestion.
Therefore,the correct location is the fundic part of the stomach.
These cells are responsible for the secretion of proenzymes such as pepsinogen and prorennin,which are essential for protein digestion.
Therefore,the correct location is the fundic part of the stomach.
0 likesView Solution
105
BiologyMediumMCQAIPMT · 1990
The secretion of pancreatic juice is stimulated by:
A
Enterokinase
B
Cholecystokinin
C
Trypsinogen
D
Secretin
Solution
(D) The secretion of pancreatic juice is primarily regulated by gastrointestinal hormones.
$1$. $Secretin$ acts on the exocrine pancreas to stimulate the secretion of water and bicarbonate ions.
$2$. $Cholecystokinin$ $(CCK)$ stimulates the pancreas to secrete digestive enzymes.
Since both hormones are involved,and $Secretin$ is the primary hormone known for stimulating the watery component of pancreatic juice,in many contexts,both are considered correct. However,$Secretin$ is the classic answer for the stimulation of pancreatic juice secretion (specifically the bicarbonate-rich fluid).
Therefore,the most appropriate answer is $Secretin$.
$1$. $Secretin$ acts on the exocrine pancreas to stimulate the secretion of water and bicarbonate ions.
$2$. $Cholecystokinin$ $(CCK)$ stimulates the pancreas to secrete digestive enzymes.
Since both hormones are involved,and $Secretin$ is the primary hormone known for stimulating the watery component of pancreatic juice,in many contexts,both are considered correct. However,$Secretin$ is the classic answer for the stimulation of pancreatic juice secretion (specifically the bicarbonate-rich fluid).
Therefore,the most appropriate answer is $Secretin$.
0 likesView Solution
106
BiologyEasyMCQAIPMT · 1990
The epithelium of the alveoli in the lungs is .......... .
A
Non-ciliated columnar
B
Non-ciliated squamous
C
Ciliated columnar
D
Ciliated squamous
Solution
(B) The alveoli in the lungs are the primary sites for the exchange of gases.
To facilitate efficient diffusion of gases,the wall of the alveoli must be extremely thin.
This is achieved by a single layer of flat,thin,and scale-like cells known as squamous epithelium.
Since these cells do not possess cilia,the epithelium of the alveoli is classified as non-ciliated squamous epithelium.
To facilitate efficient diffusion of gases,the wall of the alveoli must be extremely thin.
This is achieved by a single layer of flat,thin,and scale-like cells known as squamous epithelium.
Since these cells do not possess cilia,the epithelium of the alveoli is classified as non-ciliated squamous epithelium.
0 likesView Solution
107
BiologyEasyMCQAIPMT · 1990
In which of the following is the skin an accessory respiratory organ?
A
Humans
B
Frog
C
Rabbit
D
Lizard
Solution
(B) In amphibians like the $Frog$ $(Rana \, tigrina)$, the skin is moist and highly vascularized, which allows for cutaneous respiration. This serves as an accessory respiratory organ, especially when the animal is underwater or hibernating, supplementing the primary pulmonary respiration.
0 likesView Solution
108
BiologyMediumMCQAIPMT · 1990
The lumen of a vein is wider because ........
A
The tunica externa and tunica media form a single layer.
B
The tunica interna and tunica media form a single layer.
C
The tunica interna,tunica media,and tunica externa are thin.
D
The tunica media is a thin layer.
Solution
(D) Blood vessels are composed of three layers: $Tunica$ $interna$ (innermost),$Tunica$ $media$ (middle),and $Tunica$ $externa$ (outermost).
In arteries,the $Tunica$ $media$ is very thick and muscular to withstand high blood pressure,which results in a narrow lumen.
In contrast,veins have a much thinner $Tunica$ $media$ compared to arteries.
Because the $Tunica$ $media$ is thin in veins,the vessel wall is less thick,which allows the lumen to be significantly wider than that of an artery.
In arteries,the $Tunica$ $media$ is very thick and muscular to withstand high blood pressure,which results in a narrow lumen.
In contrast,veins have a much thinner $Tunica$ $media$ compared to arteries.
Because the $Tunica$ $media$ is thin in veins,the vessel wall is less thick,which allows the lumen to be significantly wider than that of an artery.
0 likesView Solution
109
BiologyMediumMCQAIPMT · 1990
The splenic artery arises from the ..........
A
Superior mesenteric artery
B
Celiac artery
C
Inferior mesenteric artery
D
Mesenteric artery
Solution
(B) The $Celiac$ $artery$ (also known as the $Celiac$ $trunk$) is the first major branch of the abdominal aorta.
It divides into three main branches: the left gastric artery,the common hepatic artery,and the splenic artery.
Therefore,the splenic artery arises from the celiac artery.
It divides into three main branches: the left gastric artery,the common hepatic artery,and the splenic artery.
Therefore,the splenic artery arises from the celiac artery.
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 1990?
There are 171 Biology questions from the AIPMT 1990 paper on Vedclass, each with a detailed step-by-step solution in English.
Are AIPMT 1990 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 1990 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 1990 Biology questions, set difficulty, and generate Set A/B/C/D in 2 minutes.