CBSE Class 11 Biology Revision Assignment

Question 1. Who introduced Binomial nomenclature?
Answer: Carolus Linnaeus introduced the system of binomial nomenclature.
In simple words: Carolus Linnaeus gave every organism a two-part scientific name consisting of a genus and a species.

Exam Tip: Remember to write Carolus Linnaeus and note that binomial means two names.

Question 2. Write the following scientific name correctly – man, leopard, housefly, potato, tiger, lion and wheat.
Answer: The correctly written scientific names following standard binomial nomenclature rules (italicized when printed, underlined when handwritten, genus capitalized, species in lowercase) are:
1. Man: Homo sapiens
2. Leopard: Panthera pardus
3. Housefly: Musca domestica
4. Potato: Solanum tuberosum
5. Tiger: Panthera tigris
6. Lion: Panthera leo
7. Wheat: Triticum aestivum
In simple words: Scientific names always start with a capital letter for the genus and a small letter for the species.

Exam Tip: Always underline separately when handwritten or italicize when typed to score full marks in naming questions.

Question 3. How are taxonomic studies useful for human being?
Answer: Taxonomic studies are useful in the following ways:
1. They help in the identification of unknown and new organisms.
2. They provide information regarding agriculture, forestry, and industry.
3. They help in knowing the evolutionary relationships (phylogeny) between different organisms.
4. They help in identifying useful and harmful plants and animals.
In simple words: Taxonomy helps us classify, identify, and make use of various plants and animals in our daily life.

Exam Tip: Mention key application areas like agriculture, medicine, and forestry for a complete answer.

Question 4. Name two famous botanical garden of India.
Answer: Two famous botanical gardens in India are:
1. Indian Botanical Garden, Howrah (Kolkata)
2. National Botanical Research Institute (NBRI), Lucknow
In simple words: These gardens maintain living plant collections for scientific study and public education.

Question 5. Differentiate between- (a) herbarium and botanical garden (b) museum and zoological parks.
Answer: (a) Herbarium vs Botanical Garden:
- Herbarium: It is a collection of dried, pressed, and preserved plant specimens mounted on sheets according to a universally accepted classification system.
- Botanical Garden: It is a collection of living plants grown for reference, identification, and conservation purposes.
(b) Museum vs Zoological Parks:
- Museum: It is a repository of preserved plant and animal specimens kept in containers or jars with preservative solutions or as dry specimens and skeletons for study and reference.
- Zoological Park: It is a fenced facility where live wild animals are kept in protected environments simulating their natural habitats for public exhibition and study.
In simple words: Herbaria and museums use dead preserved specimens, whereas botanical gardens and zoos keep living plants and animals.

Exam Tip: Use a comparative tabular format in exams when differentiating between biological terms.

Question 6. How is a key helpful in the identification and classification of an organism?
Answer: A taxonomic key is an analytical tool based on contrasting characters usually in pairs called a couplet. It helps in identification by accepting one and rejecting the other statement for each contrasting character, thereby leading step by step to the correct identification and classification of an organism.
In simple words: A key works like a series of yes-or-no questions that guide you to the exact name of an unknown organism.

Exam Tip: Mention the term 'couplet' and 'lead' as they are mandatory keywords for this concept.

Question 7. Write five characteristics of living organisms.
Answer: Five defining characteristics of living organisms are:
1. Growth (increase in mass and number of individuals)
2. Reproduction (production of progeny possessing features similar to parents)
3. Metabolism (sum total of all chemical reactions occurring in the body)
4. Cellular organization (body made up of one or more cells)
5. Consciousness (ability to sense surroundings and respond to environmental stimuli)
In simple words: Living beings grow, reproduce, perform chemical reactions, possess cells, and respond to their environment.

Exam Tip: Highlight that metabolism and consciousness are defining properties without exceptions, whereas growth and reproduction have exceptions.

Question 8. Illustrate the taxonomical hierarchy with suitable of a plant and an animal.
Answer: The taxonomic hierarchy from highest to lowest rank is: Kingdom -> Phylum/Division -> Class -> Order -> Family -> Genus -> Species.
Example 1 (Plant - Wheat):
- Kingdom: Plantae
- Division: Angiospermae
- Class: Monocotyledonae
- Order: Poales
- Family: Poaceae
- Genus: Triticum
- Species: aestivum
Example 2 (Animal - Human):
- Kingdom: Animalia
- Phylum: Chordata
- Class: Mammalia
- Order: Primates
- Family: Hominidae
- Genus: Homo
- Species: sapiens
In simple words: Taxonomic hierarchy arranges organisms from broad categories down to specific individual species.

Exam Tip: Learn the complete classification chart of at least one plant (like Wheat or Mango) and one animal (like Human or Housefly).

Question 9. What is biological classification? How is it done?
Answer: Biological classification is the scientific process of grouping organisms into categories based on easily observable morphological, physiological, and evolutionary relationships. It is done by examining similarities and differences in structures, internal anatomy, cell structure, developmental processes, and ecological information.
In simple words: Biological classification is organizing living things into groups based on their shared physical and genetic traits.

Exam Tip: Emphasize that modern classification also incorporates evolutionary (phylogenetic) relationships.

Question 10. Arrange the following in correct sequence- class, family, genus, kingdom,species, order, and phylum/division.
Answer: The correct descending sequence of taxonomic categories is:
Kingdom -> Phylum / Division -> Class -> Order -> Family -> Genus -> Species
In simple words: Categories are arranged from the largest, most inclusive group (Kingdom) down to the specific individual organism (Species).

Exam Tip: Remember the mnemonic "Keep Pots Clean Or Family Gets Sick" (Kingdom, Phylum, Class, Order, Family, Genus, Species).

Question 11. Why was two kingdom classification found inadequate to classify living organisms? Give three reasons.
Answer: The two-kingdom classification (Plantae and Animalia) proposed by Linnaeus was inadequate because:
1. It did not distinguish between prokaryotes (bacteria) and eukaryotes (fungi, plants, and animals).
2. It grouped unicellular organisms (like Chlamydomonas) and multicellular organisms together without distinction.
3. It failed to differentiate between photosynthetic organisms (plants) and non-photosynthetic organisms (fungi), even though fungi have chitinous cell walls unlike plants.
In simple words: The old two-kingdom system failed because it mixed unicellular with multicellular, and fungi with plants, ignoring cell structure.

Question 12. a) Name three groups of organisms which are acellular. b)Why did Whittakar not put viruses in five kingdom classification?
Answer: a) Three groups of acellular entities are Viruses, Viroids, and Lichens (or Prions).
b) Whittaker did not include viruses in his five-kingdom classification because viruses are non-cellular organisms that do not possess a cellular structure, metabolic machinery, or independent living status outside a host body.
In simple words: Viruses are considered non-living particles outside host cells, so they do not fit into any cellular kingdom.

Exam Tip: Clearly state that viruses lack cellular machinery, which is why they are outside Whittaker's system.

Question 13. Distinguish between: (a) Plant virus and animal virus (b) Virus and viroids (c) Mycobionts and phycobionts (d) Ascospores and basideospores (e) Plasmogamy and karyogamy
Answer: (a) Plant virus vs Animal virus:
- Plant Virus: Generally contain single-stranded RNA as genetic material and infect plants.
- Animal Virus: Generally contain single or double-stranded RNA or double-stranded DNA and infect animals.
(b) Virus vs Viroids:
- Virus: Contain a protein coat (capsid) enclosing genetic material (RNA or DNA).
- Viroid: Infectious RNA particles lacking the protein coat, discovered by T.O. Diener.
(c) Mycobionts and Phycobionts:
- Mycobiont: The fungal component of a lichen, which provides shelter and absorbs mineral nutrients and water.
- Phycobiont: The algal component of a lichen, which prepares food through photosynthesis.
(d) Ascospores and Basidiospores:
- Ascospore: Sexual spores produced endogenously inside an ascus in Ascomycetes fungi.
- Basidiospore: Sexual spores produced exogenously on a basidium in Basidiomycetes fungi.
(e) Plasmogamy and Karyogamy:
- Plasmogamy: Fusion of cytoplasm between two motile or non-motile gametes.
- Karyogamy: Fusion of two nuclei following plasmogamy.
In simple words: These pairs represent contrasting biological structures and reproductive steps in microbes and fungi.

Exam Tip: For viroids, always mention the absence of a protein coat and smaller size compared to viruses.

Question 14. Give one word answer: (a) Pollution indicator organism b)Bacteria that live in marshy areas c)Bacteria that live in salty areas d)Who proposed two kingdom classification e)Who proposed five kingdom classification f)Smallest cell g)Specialized cell of Cyanobacteria that fix atmospheric nitrogen h)Chief producer of ocean which are mainly phytoplankton i)Common name of ascomycetes and basideomycetes
Answer:
(a) Lichen
(b) Methanogens (Archaebacteria)
(c) Halophiles (Archaebacteria)
(d) Carolus Linnaeus
(e) R.H. Whittaker
(f) Mycoplasma
(g) Heterocyst
(h) Diatoms
(i) Sac fungi (for Ascomycetes) and Club fungi (for Basidiomycetes)
In simple words: These are direct one-word biological terms for specific organisms and classifications.

Exam Tip: Memorize these exact terms as they frequently appear in 1-mark objective questions.

Question 15. Identify the type of bacteria in the given figures below:
Answer: Based on standard NCERT diagrams (Chapter 2 - Biological Classification):
1. Bacteriophage (Virus with head, collar, sheath, and tail fibres)
2. Filamentous Cyanobacteria / Nostoc (showing heterocyst and mucilaginous sheath)
3. Bacterial shapes: Coc bacilli, Spirillum, and Flagellated bacilli.
4. Tobacco Mosaic Virus (TMV) showing RNA and Capsid.
5. Mushroom (Basidiomycete fruiting body).
In simple words: The figures represent bacteriophage, cyanobacteria, bacterial shapes, TMV, and a mushroom.

Exam Tip: Practice labeling standard NCERT biology diagrams, especially bacteriophage and TMV.

1. Who introduced Binomial nomenclature?

2. Write the following scientific name correctly – man, leopard, housefly, potato, tiger, lion and wheat.

3. How are taxonomic studies useful for human being?

4. Name two famous botanical garden of India.

5. Differentiate between-

(a) herbarium and botanical garden

(b) museum and zoological parks.

6. How is a key helpful in the identification and classification of an organism?

7. Write five characteristics of living organisms.

8. Illustrate the taxonomical hierarchy with suitable of a plant and an animal.

9. What is biological classification? How is it done?

10. Arrange the following in correct sequence- class, family, genus, kingdom,species, order,and phylum/division.

11.Why was two kingdom classification found inadequate to classify living organisms? Give three reasons.

12. a) Name three groups of organisms which are acellular.

b) Why did Whittakar not put viruses in five kingdom classification?

13.Distinguish between:

1. How is dicot stem different from monocot stem anatomically?

2. Does secondary growth occur in dicot root? If yes, then diagrammatically depict the same.

3. Describe the internal structure of a dorsiventral leaf, with the help of labelled diagram.

4. Explain the process of occurrence of secondary growth in the stems of woody angiosperms with the help of schematic diagrams.

5. What is periderm? How does periderm formation take place in dicot stems?

6. State the location and function of different types of meristematic tissues in plants.

7. Take one flower each of the families of Fabaceae and write its semi-technical definitions along with floral formula. Also draw their floral diagram.

8. Take one flower each of the families of Liliaceae and write its semi-technical definitions along with floral formula. Also draw their floral diagram.

9. Take one flower each of the families of Solanaceae and write its semi-technical definitions along with floral formula. Also draw their floral diagram.

10. What is phyllotaxy? How is a pinnately compound leaf different from a palmately compound leaf?

11. Draw and describe the different types of aestivation found in flowering plants along with diagrams.

12. How are leaves modified to perform additional functions, explain with suitable example.

13. a) What is heartwood and sapwood?

b) Write the features of autumn wood and spring wood.

Que A :Fill in the blanks using suitable words:

1. In the flower of Brinjal the Ovary is_______ .

2. Chlamydomonas is a _________ algae.

3. Floral formula of Brassicaceae is___________________.

4. _________ tissue provides flexibility to the petiole.

5. Modification of stem in Opuntia for the purpose of photosynthesis is known as ____________.

Que B: Answer the following questions in brief:

1. What are mycorrhizae?

2. What are polysomes?

3. What is coleoptiles?

4. What is meant by endarch xylem?

Que C: Give scientific reasons for the following:

1. Lysosomes are called as suicidal bag of a cell.

2. Tapeworm (Taenia solium) do not possess digestive system.

3. Earthworm (being Hermaprodite )do not show self fertization.

1. How is valvate aestivation different from twisted aestivation? 

2. Give one evidence to show that viruses are smaller than bacteria. 

3. Which plant part has transformed into the following different modifications?

(i) Thorn of citrus (ii) Tendril of pea 

4. How do you represent by symbols the following in a floral formula? (i) Zygomorphic (ii) Adhesion between Corolla and Androecium 

5. What are botanical gardens? Name two botanical gardens of India 

6. Define order. Give example. 

7. What is meant by ‘ Contagium Vivum Fluidum’ ? Who gave this idea? 

8. What the terms ‘algal bloom’ and ‘red tides’ signify? 

9. What is the structural difference between tendril of pumpkin and pea? 

10. Write floral formula of family- Solanaceae 

11. How are Ascomycetes different from Basidiomycetes? 

12. How systematic is different from taxonomy? 

13. Differentiate between axile and free central aestivation. Draw diagram. 

14. How basidiomycetes is different from ascomycetes? 

15. Differentiate between hypogynous and epigynous flower with an example of each.

16. How is key helpful in the identification and classification of an organism? 

17. How are archaebacteria able to live in extreme environmental conditions? Mention two such conditions in which they live. 

18. Differentiate between phototrophic and chemotrophic bacteria. 

19. How are mycoplasma different from other prokaryotes? Name two diseases they cause in animals.

20. Name the fungus called as ‘Drosophila’ of this kingdom. Why? 

21. Mention the modified function performed by: 

a. Underground stem of potato

b. Axillary bud of Citrus

22. How would you differentiate the leaflets of a compound leaf from simple leaves on a branch? Give an example of a plant with bipinnate leaves? 

23. What are bracteates and ebracteate flowers? 

24. When are stamens described as epipetalous? Give an example. 

25. Name two medicinal plants of Solanaceae.

26. Differentiate between androecium of Fabaceae and Solanaceae. 

27. Distinguish between simple epithelium and compound epithelium. 

28. Distinguish between dense regular and dense irregular connective tissue.

29. What are mosaic vision? Name the animal that has mosaic vision. 

30. What is meant by Km value in enzyme reaction? What does in indicate?

31. Bring out the differences between ligase and lyases. 

32. Write how herbarium and museums can be used as taxonomical aids?

33. Explain the modes of nutrition in Eubacteria. 

34. Describe the classification of flowers on the basis of position of ovary. Draw diagram.

35. Write about any two types of protozoa with examples of each. 

36. Describe with the help of diagram the different regions of a root. 

37. (a) Why are cyanobacteria used as biofertilizers?
(b) What do the terms phycobiont and mycobiont signify?
(c) How are mycoplasma different from other prokaryotes? 

38. Name the three basic tissue systems in the flowering plants. Give the tissue names under each system. 

39. Name the three permanent tissues found in flowering plants. Write one function for each. 

40. What is meant by (i) open and (ii) closed vascular bundles 

41. Differentiate between the anatomy of a dorsiventral leaf and that of an isobilateral leaf. 

42. Both lysosomes and vacuoles are endomembrane structures, yet they differ in terms of their functions. Comment. 

43. Bring out the differences between primary and secondary metabolities. Name as example for each of them. 

44. Illustrate a glycosidic, a peptide and phosphodiester bond. 

45. Name the three substages of interphase and enumerate the events in each of them. 

46. Describe Prophase I in detail. 

47. Describe the events that occur in Anaphase I along with a diagram. 

48. Describe the structure of a cilium/flagellum as seen under electron microscope. Bring out the differences between cilium and centriole. 

49. (a) What are the advantages of giving scientific names of the organism?
What is the correct way of writing a scientific name? Illustrate with example.
(b) Define family. Name two genera included in the family felidae.

1. Name the element which is required for keeping two sub-units of ribosomes together.

2. Define Coenocyte, Syncytium.

3. Name the non-living components of a cell.

4. What are plasmids? Describe their significance.

5. Write a short note on plastids. Are different types of plastids interchangeable? If yes, give examples.

6. Draw well labelled diagram of organelles which are semiautonomous and also give reason. Why are they called so?

7. Match the items of List I and List II.

         I                                                  II

1. Microbodies                 contain digestive enzymes

2. Air Vacuoles                 store & concentrate mineral salts and nutrients.

3. Food vacuoles              osmoregulation

4. Contractile vacuoles     enzyme for Peroxide Metabolism

5. Sap vacuole                 store metabolic gases.

8. What are different types of Chromosomes on the basis of position of Centromere.