Most Important Biology Diagram For NEET UG 2026: Biology plays a decisive role in NEET UG, and mastering diagrams can give you a clear edge over the competition. In this article on the Most Important Biology Diagrams for NEET UG 2026, we bring you a focused collection of high-yield diagrams that are frequently tested and conceptually crucial. A clear understanding of these diagrams not only helps in direct questions but also strengthens your grasp of complex biological processes.
HUMAN STOMACH
The stomach, located in the upper left portion of the abdominal cavity, has three major parts – a cardiac portion into which the oesophagus opens, a fundic region, and a pyloric portion which opens into the first part of the small intestine (Figure 1.3). The small intestine is distinguishable into three regions: a ‘C’ shaped duodenum, a long coiled middle portion jejunum, and a highly coiled ileum. The opening of the stomach into the duodenum is guarded by the pyloric sphincter. The ileum opens into the large intestine. It consists of caecum, colon and rectum. Caecum is a small blind sac that hosts some symbiotic microorganisms.
Key Points & NEET Tips
- Pyloric sphincter regulates food entry into intestine
- HCl is secreted by parietal (oxyntic) cells
- Pepsinogen → pepsin (activated by HCl)
- Mucus protects stomach lining from acid
- Fundus acts as storage area
PRACTICE MCQ BASED ON THE DIAGRAM
Q1. Which cells secrete HCl in the stomach?
A. Chief cells
B. Goblet cells
C. Parietal cells
D. Enteroendocrine cells
Q2. Pyloric sphincter opens into which part?
A. Jejunum
B. Ileum
C. Duodenum
D. Colon
Q.3. In the given diagram showing anatomical regions of the human stomach, A, B and C respectively represent:
1. Fundus, Cardiac and Pylorus
2. Cardiac, Pylorus and Fundus
3. Fundus, Pylorus and Cardiac
4. Pylorus, Cardiac and Fundus
Join NEET News 2026 - Answer: C
- Answer: C
- Answer: A
Read Also: Most Important Biology Diagram For NEET UG 2026 to Score 650+
TS SECTION OF STOMACH
Serosa:
Outermost layer of the stomach, also called visceral peritoneum; made of mesothelium and connective tissue.
Muscularis:
Formed of smooth muscles arranged in inner circular and outer longitudinal layers; helps in mixing food.
Submucosa:
Loose connective tissue layer containing blood vessels, lymph vessels, and nerves.
Mucosa:
Innermost layer with secretory and absorptive cells; forms rugae that increase surface area and disappear on distension; contains mucus-secreting goblet cells for lubrication and protection.
PRACTICE MCQ BASED ON THE DIAGRAM
Q.1. The intrinsic nervous system that is responsible for peristalisis is present in which part shown in the given tranverse section of the human gut?
1. A
2. B
3. C
4. D
Q.2. Goblet cells secreting mucus are present in:
A. Submucosa
B. Serosa
C. Muscularis
D. Mucosa
Answer. 1. B
Answer. 2. C
HUMAN HEART
The heart is made up of four chambers, namely, right atrium, right ventricle, left atrium, and left ventricle. In the first chamber, the right atrium receives the blood from veins and then pumps into the right ventricle. In the second chamber, the right ventricle receives the blood from the right atrium and then pumps into lungs, where it gets loaded with the oxygen. In the third chamber, the left atrium receives the oxygenated blood from lungs and then pumps into the left ventricle. In the fourth chamber, the left ventricle pumps blood to the other body parts. This blood is rich in oxygen.
PRACTICE MCQ BASED ON THE DIAGRAM
Q.1. In the given section of the human heart which part ensures that atria contract prior to the ventricles?
1. A
2. B
3. C
4. D
Q.2. In a standard human heart diagram, which numbered structure most likely represents the left ventricle?
A. A thin-walled upper chamber shown on the right side of the page
B. A thick-walled lower chamber shown on the left side of the page
C. A thick-walled lower chamber shown on the right side of the page
D. A thin-walled upper chamber shown on the left side of the page
Answer 1. B
Answer 2. B
As you revise these important Biology diagrams, make it a habit to practice labeling and visual recall regularly. These small but consistent efforts can significantly boost accuracy and save valuable time in the exam. Stay connected with our daily revision series and keep refining your preparation, because strong diagram-based understanding can be the difference between an average score and a top NEET UG 2026 rank.
Read Also: NEET UG Daily Practice Questions For 2026 to score 650+ (DAY 16)
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