IIT JAM Biotechnology Question Paper 2025 with Solutions: Download Previous Year Question Papers

IIT JAM Biotechnology Exam Pattern Overview

The IIT JAM Biotechnology exam in 2025 consisted of three sections: Multiple Choice Questions (MCQs), Multiple Select Questions (MSQs), and Numerical Answer Type (NAT) questions. The exam lasted for three hours and was conducted for a total of 100 marks. The sections were structured as follows:

Here is the detailed structure of the IIT JAM exam pattern and IIT JAM negative marking scheme:

How to Use This Question Paper for Preparation

For students preparing for IIT JAM Biotechnology in future sessions, practising IIT JAM previous year question papers is highly recommended. Here’s how aspirants can effectively use this 2025 question paper:

• Familiarity with Exam Pattern: Solving the paper helps students understand the structure of questions, the marks distribution, and the difficulty level.

• Time Management: Practising under timed conditions trains candidates to manage the three-hour duration effectively and prioritise questions wisely.

• Identifying Important Topics: Analysing repeated topics and frequently asked questions can guide aspirants to focus on high-weightage areas in biotechnology.

• Self-Assessment: After attempting the paper, students can evaluate their IIT JAM preparation by comparing their answers with the solution, thus identifying weak areas and improving systematically on them.

IIT JAM Biotechnology 2025 Questions with Solutions

Question 1. The porphyrin ring (tetrapyrrole structure) is NOT found in functional

(A) chlorophyll

(B) hemoglobin

(C) hemocyanin

(D) leghemoglobin

Answer:

The porphyrin ring, also known as the tetrapyrrole structure, is a common component in many biologically important molecules such as chlorophyll, hemoglobin, and leghemoglobin. In chlorophyll, it coordinates a central magnesium ion and plays a key role in photosynthesis. Hemoglobin and leghemoglobin both contain a heme group, which is a porphyrin ring with a central iron ion, essential for oxygen binding and transport in animals and nitrogen-fixing plants, respectively. However, hemocyanin, which is found in some mollusks and arthropods, does not contain a porphyrin ring; instead, it uses copper ions to bind oxygen. Thus, the correct answer is (C) hemocyanin.

Question 2. If $P=\left(\begin{array}{cc}\cos \alpha & \sin \alpha \\ -\sin \alpha & \cos \alpha \end{array}\right)$ and $P+P^T=I$, the value of $\alpha (0\le \alpha \le \pi /2)$ is

(A) $\frac{\pi }{2}$

(B) $\frac{\pi }{3}$

(C) $\frac{3\pi }{2}$

(D) 0

Answer:

We are given:

$P=\left(\begin{array}{cc}\cos \alpha & \sin \alpha \\ -\sin \alpha & \cos \alpha \end{array}\right)$

Transpose is:

$P^T=\left(\begin{array}{cc}\cos \alpha & -\sin \alpha \\ \sin \alpha & \cos \alpha \end{array}\right)$

Now add:

$P+P^T=\left(\begin{array}{cc}\cos \alpha +\cos \alpha & \sin \alpha -\sin \alpha \\ -\sin \alpha +\sin \alpha & \cos \alpha +\cos \alpha \end{array}\right)$

$=\left(\begin{array}{cc}2\cos \alpha & 0\\ 0& 2\cos \alpha \end{array}\right)$

Condition given:

$P+P^T=I=\left(\begin{array}{cc}1& 0\\ 0& 1\end{array}\right)$

So, $2\cos \alpha =1\Rightarrow \cos \alpha =\frac{1}{2}$

$\alpha ={\displaystyle \frac{\pi }{3}}$ (since $0\le \alpha \le {\displaystyle \frac{\pi }{2}}$).

Answer: (B) ${\displaystyle \frac{\pi }{3}}$

Question 3. After how many cycles of polymerase chain reaction (PCR), the amplified product of the required length is generated for the first time from a chromosomal DNA template?

(A) 2

(B) 3

(C) 4

(D) 5

Answer:

In a polymerase chain reaction (PCR), the first two cycles produce DNA fragments that are longer than the desired target sequence, as the DNA polymerase extends beyond the binding sites of the primers. It is only after the third cycle that DNA fragments of the defined, required length—bounded by both forward and reverse primers—are produced for the first time. These correctly sized products then accumulate exponentially in subsequent cycles. Therefore, the required-length amplified product is first generated after 3 cycles, making the correct answer (B) 3.

Question 4. In humans, Down syndrome is caused by

(A) Trisomy 16

(B) Trisomy 18

(C) Trisomy 21

(D) Trisomy 22

Answer:

In humans, Down syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21, a condition known as trisomy 21. This results in a total of 47 chromosomes instead of the normal 46. Individuals with Down syndrome typically show developmental delays, characteristic facial features, and varying degrees of intellectual disability.

Therefore, the correct answer is (C) Trisomy 21.

Question 5. Which one of the following hormones is produced by the adrenal gland?

(A) Thyroxine

(B) Cortisol

(C) Insulin

(D) Melatonin

Answer:

The adrenal gland produces several important hormones, including cortisol, which is a steroid hormone secreted by the adrenal cortex. Cortisol plays a vital role in regulating metabolism, immune response, and stress.

Let's briefly review the other options:

• Thyroxine – Produced by the thyroid gland.

• Insulin – Produced by the pancreas (beta cells of the islets of Langerhans).

• Melatonin – Produced by the pineal gland.

Therefore, the correct answer is (B) Cortisol.

Accessing the Question Paper and Solutions

The official Biotechnology IIT JAM question paper 2025 and answer key are available for download from the official IIT JAM website. Students can refer to these resources for accurate solutions and detailed explanations:

• IIT JAM 2025 Biotechnology Question Paper PDF
  

• IIT JAM 2025 Biotechnology Answer Key