📖 11th Botany Important Two Mark Questions 2025

📚 Score High with 11th Botany 2-Mark Questions!
This 11th Botany Two Marks Important Questions Guide is specially designed for Tamil Nadu 11th Public Exam 2025 students. It contains chapter-wise two-mark questions, carefully selected from previous year question papers, model exams, and textbook exercises. These frequently asked 2-mark questions help students cover essential concepts and definitions in a short and precise manner.

✔ Based on Tamil Nadu 11th Board Exam Syllabus
✔ Chapter-wise 2-Mark Questions with Answers
✔ Covers Definitions, Functions & Key Concepts
✔ Includes Previous Year Public Exam Questions

Most Important Diagram Two Marks

Draw and label the parts

  1. Draw and label the structure of Mycoplasma.Ch1 – 2 times
  2. Draw the diagram of a stamen and label its parts.Ch4 Pg87
  3. Draw the floral diagram of Musa paradisiaca.Ch5 Pg133
  4. Draw the diagram of leaf and label the parts?Pg57 Ln3
  5. Draw and label the diagram of an amphicribral vascular bundle(All Type).Ch9 Pg209
  6. Draw the structure of mitochondria and label the parts.Ch6
  7. Identify the given diagram (phloem and xylem cross-section).

Most Repeated Two Marks

  1. What is sterigma?Ch1 – 5 times
  2. What is nucule?Ch2 – 4 times
  3. What is plectostele? Give an example.Ch2 – 3 times
  4. Differentiate Oidium and Chlamydospore.Ch1 – 3 times
  5. Write any two functions of the stem.Ch3 – 3 times
  6. Why do the cells of sclerenchyma and tracheids become dead?Ch9 BB6 – 3 times
  7. What are the parameters which control water potential?Ch11 – 3 times
  8. Write the types of chromosomes based on the centromere.Ch6 – 2 times
  9. What is Richmond Lang effect? – 2 times
  10. Respiratory quotient is zero in succulent plants. Why? – 2 times
  11. Define cell cycle. – 2 times
  12. What is osmotic potential? – 2 times
  13. What is interfascicular cambium?Ch15 – 2 times
  14. What is a mesophyll cell?Ch9 – 2 times
  15. Write the floral formula of Datura metel.Ch5 – 2 times
  16. What is activation energy?Ch8 – 2 times
  17. Write about the Gynoecium of Datura metel.Ch5 – 2 times
  18. Write any two characteristic features of the stem.Ch3 – 2 times
  19. What are NPK fertilizers? Ch12 Pg262- 2 times
  20. Differentiate nucleoside and nucleotide.Ch8 – 2 times
  21. What is wood botanically?Ch10 – 2 times

Chapter Wise Important Two Marks

Chapter 1

  1. Mention plant diseases caused by fungi. (Pg27)
  2. Which organism imparts red color to the Red Sea? (Pg19)
  3. Write the merits of the five-kingdom system of classification.
  4. What is oogamy? Give an example. (Pg22)
  5. What are magnetosomes? (Pg14)
  6. What is capnophilic bacterium?Ln1
  7. Differentiate homoiomerous and heteromerous lichens?Ln1 Q6
  8. Which impart “earthy odour” to soil after rain?Ln1 Pg20
  9. What are called mycorrhizae?Ln1 Pg27
  10. why do farmers plant leguminous crops in crop rotations and mixed cropping?Ln1 BB8

Chapter 2

  1. Mention the types of rhizoids in bryophytes.
  2. What is amber? Which group of plants produce amber? (Pg50)
  3. Write the three classes of gymnosperms. (Pg51)
  4. Mention two characters shared by gymnosperms and angiosperms.
  5. Write the differences between monoxylic wood and pycnoxylic wood. (Pg51)
  6. What is Eustele?Ln2 pg41
  7. What do you infer from the term pycnoxylic?Ln2 BB7
  8. Do you agree with the statement ‘Bryophytes need water for fertilization’? Justify your answer?Ln2 BB10
  9. Which plant groups is called ‘vascular cryptogams’why?Ln2 Pg45
  10. Differentiate haplontic and diplontic life cycle? Ln2 Pg34

Chapter 3

  1. List out the functions of a leaf.
  2. What is phyllotaxy?
  3. What are called root climbers? Give an example. (Pg68)
  4. Write a short note on pulvinus. (Pg71)
  5. write the primary functions of root?Ln3 Pg50
  6. Define venation?Ln3 Pg72

Chapter 4

  1. What are the types of inflorescence?
  2. Find out the floral formula for a bisexual flower with bract, regular, pentamerous, distinct calyx and corolla, superior ovary without bracteole.
  3. What are called bisexual flowers?Give example Ln4 pg70
  4. Define parthenocarpic fruit?Ln 4 Pg79
  5. Define Aestivation?Ln 4 Pg72
  6. Differentiate between aggregate fruit with multiple fruit?BB9 Ln4
  7. Give the technical terms for the following:Ln4 BB7
    1. A sterile stamen
    2. Stamens are attached to the petals

Chapter 5

  1. Write any two principles of ICN.
  2. Write the floral formula (female) of Ricinus communis.
  3. what is Bio-systematics?Pg101 Ln5

Chapter 6

  1. Write the functions of the nucleus.
  2. What is plasmodesmata? (Pg152)
  3. Write a short note on cell theory.
  4. What is a middle lamellae?Ln6 Pg126

Chapter 7

  1. What is closed mitosis?
  2. What is crossing over?
  3. How does cytokinesis take place in plant and animal cells? (Pg170)
  4. Write five substages in meiosis prophase I. (Pg171)
  5. Give an account of Go phase?Ln7 Pg142
  6. write any two importance of meiotic cell division?Ln7Pg147

Chapter 8

  1. What is zwitter ion?

Chapter 9

  1. What are passage cells? (Pg211)
  2. what is bicollateral vascular bundle?Ln 9 Pg182
  3. Write a note on radial vascular bundle?Pg182 Ln9
  4. Why the cells of sclerenchyma and tracheids become dead?Ln9 BB6

Chapter 10

  1. What is dendrochronology?
  2. In which season are the vessels of angiosperms larger in size? Why?
  3. What is periderm?Pg 201 in Summary Ln10
  4. differentiate the wood formed in pinus from that of Morus?Ln10 Pg194

Chapter 11

  1. What is guttation? (Pg250)
  2. What is water potential?
  3. If the concentration of salt in the soil is too high, the plants may wilt even if the field is thoroughly irrigated. Explain.
  4. What is ascent of sap?Ln11 213
  5. Define imbibition?Pg207Ln11

Chapter 12

  1. What is guttation? (Pg250)
  2. What is water potential?
  3. If the concentration of salt in the soil is too high, the plants may wilt even if the field is thoroughly irrigated. Explain.
  4. Plant A in nutrient medium shows whiptail disease,Plant B in a nutrient medium shows a little leaf disease.Identify mineral deficiency of plant A and B? Ln12 BB 8
  5. write notes on hydroponics?Ln12 pg234
  6. Name the two bacteria that are involved  the nitrification process of nitrogen cycle?Ln12 Pg236

Chapter 13

  • Two groups (A & B) of bean plants of similar size and same leaf area were placed in identical conditions. Group A was exposed to light of wavelength
  • A tree is believed to be releasing oxygen during night time. Do you believe the truthfulness of this statement? Justify your answer by giving reasons.
  • In Botany class, teacher explains, Synthesis of one glucose requires 30 ATPs in C4 plants and only 18 ATPs in C3plants. The same teacher explains C4 plants are more advantageous than C3 plants. Can you identify the reason for this contradiction?
  • When there is plenty of light and higher concentration of O2, what kind of pathway does the plant undergo?Analyse the reasons.

Chapter 14

  1. Write the overall equation of respiration?Ln14 262
  2. What are enzymes involved in phosphorylation and dephosphorylation reactions in EMP pathway?BB6 Ln14
  3. Respiratory quotient is zero in succulent plants.why?Ln14 BB7
  4. Define apical dominance?ln15 pg281

🎯 Why Focus on 2-Mark Questions?
Two-mark questions play a crucial role in securing higher scores in the 11th Public Exam. These short and direct questions test students’ understanding of key concepts, definitions, and diagrams, making them an essential part of exam preparation.

📚 What’s Included in 11th Botany 2-Mark Questions?
🔹 Definition-Based Questions – Key terms & scientific definitions
🔹 Concept-Based Questions – Short answers covering fundamental topics
🔹 Diagram-Based Questions – Labeling & explanation of biological structures
🔹 Function-Based Questions – Role of plant parts, hormones, enzymes, etc.

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