Structural organisation in animals explains how cells form tissues, tissues form organs and organs form organ systems in multicellular animals.
Important Questions Class 11 Biology Chapter 7 help students revise frog morphology, frog anatomy and organ systems through direct and diagram-based questions.
A frog is one of the clearest examples used in class 11 biology to understand how different organ systems work together in a vertebrate. This chapter moves from tissue-level organisation to the morphology and anatomy of Rana tigrina, the common frog found in India. Students should revise external features, skin, limbs, digestion, respiration, circulation, excretion, nervous system and reproduction. The 2026-27 exam can ask direct definitions, diagram labelling, organ-system functions and short comparisons. These class 11 biology chapter 7 important questions are arranged by question type so students can revise both factual details and process-based answers.
Key Takeaways
- tissue: A tissue is a group of similar cells with intercellular substances performing a specific function.
- frog body: The body of a frog is divided into head and trunk, with no neck or tail.
- respiration: Frogs use skin in water and lungs, skin and buccal cavity on land.
- reproduction: A mature female frog can lay 2500 to 3000 ova at a time.
Important Questions Class 11 Biology Chapter 7 Structure 2026-27
| Question Type |
Marks |
Best Answer Style |
| Objective type |
1 mark |
Term, feature or correct option |
| Very short answer |
2 marks |
30-50 words with one function |
| Short answer |
3 marks |
50-80 words with labelled points |
| Long answer |
5 marks |
Organ-system explanation |
| Case-based |
4 marks |
Situation, concept and reason |
Objective Type Questions from Important Questions Class 11 Biology Chapter 7
Objective questions from this chapter test frog features, organ systems, tissue organisation and direct NCERT facts. Students should revise names and functions carefully because similar terms appear in options.
Q1. A group of similar cells with intercellular substances performing a specific function is called:
- Organ
b. Tissue
c. Organ system
d. Organism
Answer: b. Tissue
A tissue performs one or more specific functions in the body.
Q2. The study of externally visible features is called:
- Anatomy
b. Physiology
c. Morphology
d. Histology
Answer: c. Morphology
Morphology refers to the study of form and externally visible features.
Q3. The study of internal organs in animals is called:
- Anatomy
b. Ecology
c. Morphology only
d. Taxonomy
Answer: a. Anatomy
Anatomy deals with the internal structure of organs in animals.
Q4. The common frog found in India is:
- Rana tigrina
b. Pheretima
c. Periplaneta
d. Hydra
Answer: a. Rana tigrina
Rana tigrina is the common Indian frog mentioned in NCERT.
Q5. Frogs belong to:
- Class Pisces
b. Class Amphibia
c. Class Reptilia
d. Class Mammalia
Answer: b. Class Amphibia
Frogs can live both on land and in freshwater.
Q6. Frogs are called poikilotherms because:
- They have constant body temperature
b. Their body temperature changes with the environment
c. They have no lungs
d. They do not respire
Answer: b. Their body temperature changes with the environment
Poikilotherms are cold-blooded animals.
Q7. Protective colour change in frogs is called:
- Aestivation
b. Hibernation
c. Mimicry
d. Fertilisation
Answer: c. Mimicry
Frogs change colour to hide from enemies.
Q8. Summer sleep in frogs is called:
- Hibernation
b. Aestivation
c. Micturition
d. Metamorphosis
Answer: b. Aestivation
Frogs undergo aestivation during extreme summer.
Q9. The frog’s eyes are protected in water by:
- Tympanum
b. Nictitating membrane
c. Vocal sac
d. Copulatory pad
Answer: b. Nictitating membrane
The nictitating membrane protects the eyes while the frog is in water.
Q10. The tympanum in frog receives:
- Light signals
b. Sound signals
c. Chemical signals
d. Hormonal signals
Answer: b. Sound signals
The tympanum acts as the external hearing structure.
Q11. Male frogs can be identified by the presence of:
- Oviducts
b. Vocal sacs and copulatory pad
c. Ovaries
d. Webbed digits only
Answer: b. Vocal sacs and copulatory pad
These structures are absent in female frogs.
Q12. The frog’s digestive canal opens outside through the:
- Mouth
b. Cloaca
c. Ureter
d. Gall bladder
Answer: b. Cloaca
The cloaca is a common chamber for digestive, excretory and reproductive products.
Q13. Frog heart has:
- Two chambers
b. Three chambers
c. Four chambers
d. One chamber
Answer: b. Three chambers
The frog heart has two atria and one ventricle.
Q14. Frogs excrete nitrogenous waste mainly as:
- Ammonia
b. Urea
c. Uric acid
d. Carbon dioxide
Answer: b. Urea
Frogs are ureotelic animals.
Q15. External fertilisation in frogs takes place in:
- Soil
b. Water
c. Air
d. Burrows only
Answer: b. Water
Fertilisation and development in frogs are external.
Very Short Answer Questions from class 11 biology chapter 7 important questions
Very short answers from this chapter usually ask for definitions, organ names and single-function explanations. Write the direct answer first, then add one NCERT fact.
Q16. What is tissue?
A tissue is a group of similar cells along with intercellular substances performing a specific function. In multicellular animals, tissues organise to form organs and organ systems.
Q17. What is the difference between morphology and anatomy?
Morphology is the study of externally visible features. Anatomy is the study of internal organs and internal structure in animals.
Q18. Why are frogs called amphibians?
Frogs are called amphibians because they can live both on land and in freshwater. They belong to class Amphibia of phylum Chordata.
Q19. What is mimicry in frogs?
Mimicry in frogs is the ability to change body colour to match surroundings. It helps them hide from enemies and acts as protective colouration.
Q20. What is the function of the nictitating membrane?
The nictitating membrane protects the frog’s eyes while it is in water. It covers the bulged eyes and helps prevent damage.
Q21. How does a frog absorb water?
A frog does not drink water through its mouth. It absorbs water through its moist skin.
Q22. What is sexual dimorphism in frogs?
Sexual dimorphism means males and females show visible differences. Male frogs have vocal sacs and a copulatory pad on the first digit of forelimbs, which are absent in females.
Short Answer Questions from structural organisation in animals class 11 important questions
Short answer questions often focus on external features, organ-system parts and functions. Use 3-4 clear points for each answer.
Q23. Describe the external features of frog.
The body of a frog is divided into head and trunk.
A neck and tail are absent. A pair of nostrils is present above the mouth. Eyes are bulged and covered by a nictitating membrane. Tympanum is present on either side of the eyes.
Forelimbs help in walking and landing. Hind limbs are larger and help in leaping, swimming and burrowing.
Q24. Explain frog morphology class 11 in brief.
Frog morphology class 11 includes the study of the frog’s external body features.
The dorsal side is generally olive green with dark irregular spots. The ventral side is pale yellow. The skin is smooth, slippery and moist due to mucus. The body has head and trunk only. Webbed digits help in swimming.
Male frogs have vocal sacs and copulatory pads.
Q25. Describe the digestive system of frog class 11.
The digestive system of frog class 11 includes the alimentary canal and digestive glands.
The alimentary canal starts with mouth and buccal cavity. It continues into pharynx, oesophagus, stomach, intestine, rectum and cloaca. Liver secretes bile, which is stored in the gall bladder. Pancreas secretes pancreatic juice.
The bilobed tongue helps capture food.
Q26. How does respiration occur in frogs?
Frogs respire by different methods on land and in water.
In water, the skin acts as the respiratory organ. This is called cutaneous respiration. On land, frogs use buccal cavity, skin and lungs for respiration. Respiration through lungs is called pulmonary respiration.
During aestivation and hibernation, gaseous exchange occurs through skin.
Q27. Describe the circulatory system of frog class 11.
The circulatory system of frog class 11 is a closed type.
It consists of heart, blood vessels and blood. The heart has three chambers: two atria and one ventricle. It is covered by pericardium. Blood contains plasma, RBCs, WBCs and platelets.
Frog RBCs are nucleated and contain haemoglobin.
Q28. Explain the excretory system of frog class 11.
The excretory system of frog class 11 includes a pair of kidneys, ureters, cloaca and urinary bladder.
Kidneys are compact, dark red and bean-shaped. Each kidney contains uriniferous tubules or nephrons. In males, ureters act as urinogenital ducts and open into cloaca.
Frogs excrete urea, so they are ureotelic.
Q29. What are the main parts of the frog nervous system?
The frog nervous system includes central, peripheral and autonomic systems.
The central nervous system has brain and spinal cord. The peripheral nervous system has cranial and spinal nerves. The autonomic nervous system includes sympathetic and parasympathetic divisions.
There are ten pairs of cranial nerves arising from the brain.
Q30. Describe sense organs in frog.
Frogs have sense organs for touch, taste, smell, vision and hearing.
Touch is detected by sensory papillae. Taste is detected by taste buds. Smell is detected by nasal epithelium. Eyes help in vision. Tympanum and internal ears help in hearing and balance.
Eyes and internal ears are well-organised structures.
Long Answer Questions from Important Questions Class 11 Biology Chapter 7
Long answers from this chapter usually test organ systems. Add correct sequence, organs and functions.
Q31. Explain frog anatomy class 11 with major organ systems.
Frog anatomy class 11 includes the study of internal organ systems.
- Digestive system: It includes alimentary canal and digestive glands. The canal includes mouth, buccal cavity, pharynx, oesophagus, stomach, intestine, rectum and cloaca.
- Respiratory system: Frogs respire through skin in water. On land, they use skin, buccal cavity and lungs.
- Circulatory system: It is closed type. The heart has three chambers, two atria and one ventricle.
- Excretory system: It includes kidneys, ureters, urinary bladder and cloaca. Frogs are ureotelic.
- Nervous system: It includes brain, spinal cord, cranial nerves, spinal nerves and autonomic nerves.
- Reproductive system: Male frogs have testes. Female frogs have ovaries and oviducts.
These systems show division of labour in multicellular animals.
Q32. Explain digestion in frog.
The frog is carnivorous, so its alimentary canal is short.
Food is captured by the bilobed tongue and enters the buccal cavity. From there, it passes through pharynx and oesophagus into the stomach. Digestion begins in the stomach through HCl and gastric juices.
Partly digested food is called chyme. It passes into the duodenum, which receives bile and pancreatic juice through a common bile duct. Bile emulsifies fats, while pancreatic juice helps digest carbohydrates and proteins.
Final digestion takes place in the intestine. Digested food is absorbed by villi and microvilli. Undigested waste moves into the rectum and passes out through the cloaca.
Q33. Explain respiration in frog.
Frogs respire through skin, buccal cavity and lungs.
In water, the skin acts as the main respiratory organ. This is called cutaneous respiration. Dissolved oxygen diffuses through the moist skin into blood.
On land, frogs use lungs, skin and buccal cavity. Respiration through lungs is called pulmonary respiration. Air enters through nostrils into the buccal cavity and then moves into the lungs.
Lungs are elongated, pink and sac-like structures in the upper trunk region.
During aestivation and hibernation, frogs mainly exchange gases through skin. Moist skin is essential for this process.
Q34. Describe the male and female reproductive system of frog.
The reproductive system of frog class 11 includes separate male and female organs.
In male frogs, a pair of yellowish ovoid testes is attached to the upper part of kidneys by mesorchium. About 10 to 12 vasa efferentia arise from each testis. They enter the kidney and open into Bidder’s canal. Finally, sperm passes through the urinogenital duct into the cloaca.
In female frogs, a pair of ovaries is present near the kidneys. A pair of oviducts arises from the ovaries and opens separately into the cloaca.
A mature female can lay 2500 to 3000 ova at a time. Fertilisation is external and occurs in water. Development includes a tadpole stage.
Q35. Explain the ecological and economic importance of frogs.
Frogs are beneficial for humans and ecosystems.
They eat insects and protect crops from insect damage. This makes them useful for agriculture. Frogs also form an important link in food chains and food webs.
They maintain ecological balance by acting as both predator and prey. Many animals feed on frogs, while frogs control insect populations.
In some countries, muscular frog legs are used as food. However, their ecological role is more important than their food value.
Frogs are also indicators of environmental health because they are sensitive to changes in water and land habitats.
Case-Based Questions from class 11 biology chapter 7 structural organisation in animals
Case-based questions from this chapter usually connect a frog feature with its function. Identify the organ or feature first, then explain the reason.
Q36. Case Study: Frog during summer
A student notices that frogs are not commonly seen during peak summer. The teacher explains that frogs take shelter in deep burrows to protect themselves from extreme heat.
Q36(a). What is this summer sleep called?
This summer sleep is called aestivation.
Frogs undergo aestivation to survive extreme heat.
Q36(b). Why do frogs take shelter in burrows?
Frogs take shelter in burrows to protect themselves from extreme temperature and water loss.
This helps them survive unfavourable conditions.
Q36(c). Which body feature helps frogs absorb water?
The moist skin helps frogs absorb water.
Frogs do not drink water through the mouth.
Q37. Case Study: Frog in water
A frog stays underwater for a long time. It does not use lungs actively in the same way as on land. Its moist skin helps exchange gases with water.
Q37(a). Name the type of respiration shown here.
The type of respiration is cutaneous respiration.
It occurs through the skin.
Q37(b). Why must the skin remain moist?
The skin must remain moist because oxygen diffuses through the moist surface.
Dry skin reduces gaseous exchange.
Q37(c). Which respiratory organ is used mainly on land?
Lungs are used mainly on land.
This is called pulmonary respiration.
Q38. Case Study: Identifying a male frog
During a biology practical, a student observes a frog with vocal sacs and a copulatory pad on the first digit of the forelimb.
Q38(a). Is the frog male or female?
The frog is male.
Vocal sacs and copulatory pad are present in male frogs.
Q38(b). What is the term for such male-female difference?
The term is sexual dimorphism.
It means visible differences between male and female individuals.
Q38(c). What is the function of vocal sacs?
Vocal sacs help in sound production.
They are used by male frogs during calling.
Diagram-Based Questions from frog anatomy class 11
Diagram questions from this chapter can ask students to draw external features, digestive system or reproductive system of frog. Label clearly and keep the diagram neat.
Q39. Draw a labelled diagram of the digestive system of frog and mention its main parts.
The digestive system of frog includes:
- Mouth
- Buccal cavity
- Pharynx
- Oesophagus
- Stomach
- Intestine
- Rectum
- Cloaca
- Liver
- Gall bladder
- Pancreas
Food moves from mouth to cloaca through the alimentary canal. Liver and pancreas support digestion through bile and pancreatic juice.
Q40. Draw a labelled diagram of the male reproductive system of frog and mention its parts.
The male reproductive system of frog includes:
- Testes
- Vasa efferentia
- Kidneys
- Urinogenital ducts
- Cloaca
- Urinary bladder
- Fat bodies
Testes produce sperms. Vasa efferentia carry sperms to the kidney. Urinogenital ducts carry sperms and urine to the cloaca.
Chapter-Wise Revision for important questions for class 11 biology chapter 7
Important questions for class 11 biology chapter 7 should be revised in three groups: body organisation, frog morphology and frog anatomy. Body organisation helps students understand how tissues form organs and organ systems.
Frog morphology class 11 should be revised through external features. Students should remember moist skin, head and trunk division, tympanum, nictitating membrane, webbed digits, vocal sacs and copulatory pad.
Frog anatomy class 11 should be revised system-wise. Focus on digestive system of frog class 11, respiratory system of frog class 11, circulatory system of frog class 11, excretory system of frog class 11 and reproductive system of frog class 11.
For diagrams, students should practise the digestive system and reproductive system. These are directly mentioned in NCERT exercises and are useful for exam preparation.
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