Maharashtra Board Class 11 Biology Chapter 2 Systematics of Living Organisms Solutions

Systematics Of Living Organisms Class 11 Exercise Question Answers Solutions Maharashtra Board

Class 11 Biology Chapter 2 Exercise Solutions Maharashtra Board

Biology Class 11 Chapter 2 Exercise Solutions

1. Choose Correct Option.

Question (A) Which of the following shows single stranded RNA and lacks protein coat?
(a) Bacteriophage
(b) Plant virus
(c) Viroid
(d) Animal virus
Answer: (c) Viroid
In simple words: Viroids are small, circular, single-stranded RNA molecules that are infectious agents and notably lack a protein coat, distinguishing them from viruses.

🎯 Exam Tip: Understanding the structural differences between viruses, viroids, and bacteria is crucial for classification and disease identification questions.

Question (B) Causative agent of red tide is _______.
(a) Dinoflagellate
(b) Euglenoid
(c) Chrysophyte
(d) Lichen
Answer: (A) Dinoflagellate
In simple words: Red tides are harmful algal blooms caused by the rapid proliferation of certain dinoflagellate species, leading to discoloration of the water and potential toxicity.

🎯 Exam Tip: Remembering key organisms responsible for specific ecological phenomena, like dinoflagellates for red tides, is a common exam requirement.

Question (C) Select odd one out for Heterotrophic bacteria.
(a) Nitrogen fixing bacteria
(b) Lactobacilli
(c) Methanogens
(d) Cyanobacteria
Answer: (c) Methanogens or (d) Cyanobacteria
In simple words: Cyanobacteria are photoautotrophic, producing their own food using light, while methanogens are archaea that are typically chemoautotrophic, making both "odd ones out" among strictly heterotrophic bacteria.

🎯 Exam Tip: Differentiating between modes of nutrition (autotrophic, heterotrophic, chemoautotrophic) for various microbial groups is essential for classification questions.

Question (D) Paramoecium: Ciliated Protist :: Plasmodium: _______.
(a) Amoeboid protozoan
(b) Ciliophora
(c) Flagellate protozoan
(d) Sporozoan
Answer: (d) Sporozoan
In simple words: Paramoecium is known as a ciliated protist due to its cilia for locomotion, while Plasmodium, the causative agent of malaria, belongs to the Sporozoan group, characterized by the absence of locomotory organelles.

🎯 Exam Tip: Understanding the classification of protists based on their locomotory structures and parasitic lifestyles, like ciliated protists versus sporozoans, is key.

2. Answer The Following

Question (A) What are the salient features of Monera?
Answer:
Salient features of Kingdom Monera:
1. Size: The organisms included in this kingdom are microscopic, unicellular and prokaryotic.
2. Occurrence: These are omnipresent. They are found in all types of environment which are not generally inhabited by other living beings.
3. Nucleus: These organisms do not have well-defined nucleus. DNA exists as a simple double-stranded circular single chromosome called as nucleoid. Apart from the nucleoid they often show presence of extrachromosomal DNA which is small circular called plasmids.
4. Cell wall: Cell wall is made up of peptidoglycan (also called murein) which is a polymer of sugars and amino acids.
5. Membrane-bound cell organelles: Membrane-bound cell organelles like mitochondria, chloroplast, endoplasmic reticulum are absent. Ribosomes are present, which are smaller in size (70S) than in eukaryotic cells.
6. Nutrition: Majority are heterotrophic, parasitic or saprophytic in nutrition. Few are autotrophic that can be either photoautotrophs or chemoautotrophs.
7. Reproduction: The mode of reproduction is asexual or with the help of binary fission or budding. Very rarely, sexual reproduction occurs by conjugation method.
8. Examples:
Archaebacteria: e.g. Methanobacillus, Thiobacillus, etc.
Eubacteria: e.g. Chlorobium, Chromatium, and Cyanobacteria e.g. Nostoc, Azotobacter, etc.
In simple words: Kingdom Monera comprises all prokaryotic organisms, which are typically unicellular, microscopic, lack a true nucleus and membrane-bound organelles, and exhibit diverse modes of nutrition and reproduction.

🎯 Exam Tip: Focus on the distinguishing prokaryotic characteristics such as the absence of a true nucleus and membrane-bound organelles, along with the composition of their cell wall, as these are frequently tested.

Question (B) What will be the shape of a bacillus and coccus type of bacteria?
Answer:
The shape of bacillus type of bacteria is rod-shaped and coccus is spherical.
In simple words: Bacillus bacteria are rod-shaped, while coccus bacteria are spherical, representing two fundamental morphological types among prokaryotes.

🎯 Exam Tip: Remember the basic shapes of bacteria (bacillus-rod, coccus-sphere, spirillum-spiral) as they are fundamental for identification.

Question (C) Why is binomial nomenclature important?
Answer:
Binomial nomenclature is important because:
1. The binomials are simple, meaningful and precise.
2. They are standard since they do not change from place to place.
3. These names avoid confusion and uncertainty created by local or vernacular names. The organisms are known by the same name throughout the world.
4. The binomials are easy to understand and remember.
5. It indicates phylogeny (evolutionary history) of organisms.
6. It helps to understand inter-relationship between organisms.
In simple words: Binomial nomenclature provides a universally recognized, precise, and stable naming system for organisms, eliminating confusion from local names and reflecting evolutionary relationships.

🎯 Exam Tip: Be able to articulate the advantages of binomial nomenclature, such as universality, precision, and indication of evolutionary relationships, as these are core concepts in taxonomy.

3. Write Short Notes

Question (A) Write a note on useful and harmful bacteria.
Answer:
(i) Useful bacteria:
Most of the bacteria act as a decomposer. They breakdown large molecules in simple molecules or minerals. Examples of some useful bacteria:
Lactobacillus'. It helps in curdling of milk.
Azotobacter. It helps to fix nitrogen for plants.
Streptomyces: It is used in antibiotic production such as streptomycin.
Methanogens: These are used for production of methane (biogas) gas from dung.
Pseudomonas spp. and Alcanovorax borkumensis: These bacteria have the ability to destroy the pyridines and other chemicals. Hence, used to clear the oil spills.
(ii) Harmful bacteria:
This includes disease causing bacteria. They cause various diseases like typhoid, cholera, tuberculosis, tetanus, etc. Examples of some harmful bacteria:
Salmonella typhi: It is a causative organism of typhoid.
Vibrio cholerae: It causes cholera.
Mycobacterium tuberculosis'. It causes tuberculosis.
Clostridium tetani: It causes tetanus.
Clostridium spp.: It causes food poisoning.
Many forms of mycoplasma are pathogenic.
Agrobacterium, Erwinia, etc are the pathogenic bacteria causing plant diseases.
Animals and pets also suffer from bacterial infections caused by Brucella, Pastrurella, etc.
In simple words: Bacteria are crucial for ecological processes like decomposition and nutrient cycling, with many beneficial applications in medicine and industry, while others are pathogenic, causing various diseases in living organisms.

🎯 Exam Tip: When discussing beneficial and harmful bacteria, provide specific examples for each category, detailing their roles in ecosystems, industry, or disease causation.

Question (B) Write short note on five kingdom system.
Answer:
Five kingdom system of classification was proposed by R.H. Whittaker in 1969. This system shows the phylogenetic relationship between the organisms.
The five kingdoms are:
1. Kingdom Monera
2. Kingdom Protista
3. Kingdom Plantae
4. Kingdom Fungi
5. Kingdom Animalia
In simple words: The Five Kingdom System, proposed by R.H. Whittaker, classifies all organisms into Monera, Protista, Fungi, Plantae, and Animalia, based on cell structure, mode of nutrition, and body organization to reflect evolutionary relationships.

🎯 Exam Tip: Remember the proposer (R.H. Whittaker) and the year (1969) of the five-kingdom classification, along with the names of all five kingdoms, as these are basic factual recalls.

Question (C) Write short note on useful fungi.
Answer:
Economic importances of fungi are as follows:
1. Role of fungi in medicine:
(a) Antibiotic penicillin is obtained from Penicillium.
(b) Drugs like cyclosporine, immunosuppressant drugs, precursors of steroid hormones, etc are isolated from fungi.
2. Role of fungi in industries:
(a) Yeast is used in bread making. It causes dough to rise and make the bread light and spongy. It is also used in breweries or wine making industries. Sugars present in grapes are fermented by using yeast. This results in production of alcohol which is used for making wine.
(b) Lichen is a symbiotic association of algae and fungi are used in preparation of litmus paper which is used as acid-base indicator.
3. Role of fungi in food:
(a) Fungi like mushrooms are consumed as a food. These are rich source of protein.
(b) Fungi genus Penicillium helps in ripening of cheese.
4. Role of fungi as biocontrol agents:
(a) Fungi help to control growth of weeds.
(b) Pathogenic fungi like Fusarium sp., Phytophthorapalmivora, Alternaria crassa, etc act as mycoherbicides.
In simple words: Fungi are economically important for producing antibiotics, synthesizing various drugs, aiding in food production (like bread and cheese), serving as food sources (mushrooms), and acting as biocontrol agents against weeds and pests.

🎯 Exam Tip: Highlight the diverse industrial and ecological applications of fungi, from medicine and food production to their use as bio-control agents, providing specific examples for each category.

Question 4. Complete tree diagram in detail.
ℹ️ चित्र व्याख्या (Diagram Explanation): एक आंशिक वर्गीकरण वृक्ष आरेख दिखाया गया है, जिसमें 'फंगी' और 'प्रोटिस्टा' नामक शाखाओं को लेबल किया गया है, जबकि अन्य शाखाओं को रिक्त बक्सों के रूप में छोड़ दिया गया है, जिन्हें पूरा किया जाना है।
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र जैविक वर्गीकरण के पांच-राज्य प्रणाली का एक पूर्ण वृक्ष आरेख प्रस्तुत करता है, जिसमें फंगी, एनिमलिया, प्लांटी, प्रोटिस्टा और मोनेरा स्पष्ट रूप से लेबल किए गए हैं और उनकी संबंधित शाखाओं के रूप में दिखाए गए हैं।
In simple words: The question asks to complete a biological classification tree diagram, typically referring to the five-kingdom system by filling in the missing kingdoms alongside Fungi and Protista.

🎯 Exam Tip: For diagram completion questions, ensure all parts of the diagram are accurately labeled and positioned according to standard biological classification systems.

5. Draw Neat Labelled Diagrams

Question (A) Draw neat and labelled diagram of Paramoecium.
ℹ️ चित्र व्याख्या (Diagram Explanation): इस प्रश्न में पैरामीशियम का एक स्वच्छ और नामांकित आरेख बनाने के लिए कहा गया है। यह एक अंडाकार, जूते के आकार का एककोशिकीय प्रोटिस्ट है जिसमें पूरी सतह पर सिलिया और दो स्पष्ट नाभिक (माइक्रोन्यूक्लियस और मैक्रोन्यूक्लियस) होते हैं। इसमें एक मौखिक खांचा, खाद्य रिक्तिकाएं और एक सिकुड़ने वाली रिक्तिका भी होती है।
Answer:
Characteristics:
1. It belongs to kingdom Protista. It is further classified as animal like protist.
2. It lacks cell wall.
3. It shows heterotrophic and holozoic nutrition.
4. It is a ciliated protozoan where locomotion is due to cilia.
5. It has gullet (a cavity) which opens on the cell surface.
In simple words: Paramoecium is a ciliated protist, classified under Kingdom Protista, characterized by its lack of a cell wall, heterotrophic nutrition, and locomotion via numerous cilia.

🎯 Exam Tip: When drawing diagrams of microorganisms like Paramoecium, ensure all key organelles and structures, especially those related to locomotion and feeding, are clearly labeled and correctly positioned.

Quesiton (B) Draw neat and labelled diagram of Euglena.
ℹ️ चित्र व्याख्या (Diagram Explanation): इस प्रश्न में यूग्लीना का एक स्वच्छ और नामांकित आरेख बनाने के लिए कहा गया है। यह एक फ्लैगेलेटेड प्रोटिस्ट है जो स्पिंडल के आकार का होता है, जिसमें एक लंबा फ्लैगेलम, एक आईस्पॉट, क्लोरोप्लास्ट और एक सिकुड़ने वाली रिक्तिका होती है, जो इसे प्रकाश संश्लेषण और गतिशीलता दोनों को प्रदर्शित करने में सक्षम बनाती है।
Answer:
Characteristics:
It belongs to kingdom Protista. It is further classified into euglenoids.
In simple words: Euglena is a euglenoid protist from Kingdom Protista, known for its mixotrophic nature, utilizing both photosynthesis and heterotrophy.

🎯 Exam Tip: For diagrams of Euglena, clearly label the flagellum, chloroplasts, and photoreceptor as these structures highlight its unique mixotrophic characteristics.

1. Dinoflagellates:
1. They are aquatic (mostly marine) and autotrophic (photosynthetic).
2. They have wide range of photosynthetic pigments which can be yellow, green, brown, blue and red.
3. The cell wall is made up of cellulosic stiff plates.
4. A pair of flagella is present, hence they are motile.
5. They are responsible for famous 'red tide'. E.g. Gonyaulax. It makes sea appear red.

2. Euglenoids:
1. They lack cell wall but have a tough covering of proteinaceous pellicle.
2. Pellicle covering provides flexibility and contractibility to Euglena.
3. They possess two flagella, one short and other long.
4. They behave as heterotrophs in absence of light but possess pigments, similar to that of higher plants, for photosynthesis.

Question (C) Draw a neat labelled diagram of TMV.
ℹ️ चित्र व्याख्या (Diagram Explanation): इस प्रश्न में टोबैको मोज़ेक वायरस (TMV) का एक स्वच्छ और नामांकित आरेख बनाने के लिए कहा गया है। यह एक हेलिकल वायरस है जिसमें एक खोखला कोर, कैप्सोमेयर से बनी एक प्रोटीन कोट और एक एकल-स्ट्रैंडेड आरएनए जीनोम होता है, जो इसकी विशिष्ट संरचना को दर्शाता है।
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): टोबैको मोज़ेक वायरस (TMV) का यह आरेख इसकी विशिष्ट बेलनाकार संरचना को दर्शाता है जिसमें एक केंद्रीय आरएनए कोर होता है जो सर्पिल रूप से व्यवस्थित कैप्सोमेयर नामक प्रोटीन उप-इकाइयों से घिरा होता है, जो समग्र हेलिकल आकार बनाता है।
In simple words: TMV is a rod-shaped virus with a helical structure, consisting of a single-stranded RNA genome enclosed within a protein coat made of capsomeres.

🎯 Exam Tip: When illustrating TMV, ensure to clearly label the RNA and the protein capsomeres, highlighting the helical symmetry characteristic of this plant virus.

Question 6. Complete chart and explain in your word.
ℹ️ चित्र व्याख्या (Diagram Explanation): एक आंशिक प्रवाह चार्ट प्रस्तुत किया गया है जिसका शीर्षक 'वाइरस के प्रकार' है, जिसमें एक शाखा 'पशु' के रूप में लेबल की गई है जबकि अन्य शाखाओं को अधूरा छोड़ दिया गया है, जिन्हें होस्ट के आधार पर विभिन्न वायरस प्रकारों के साथ पूरा किया जाना है।
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख होस्ट के आधार पर वायरस के वर्गीकरण को दर्शाता है, जिसमें 'वाइरस के प्रकार' को 'पौधे', 'पशु' और 'बैक्टीरिया (बैक्टीरियोफेज)' नामक शाखाओं में विभाजित किया गया है, जो प्रत्येक मेजबान प्रकार के लिए विशिष्ट वायरस को दर्शाते हैं।
Depending upon the host, viruses are classified into three types as:
1. Plant virus
2. Animal virus
3. Bacterial virus (Bacteriophage)
1. Plant virus:
(a) Generally, they are rod shaped or cylindrical with helical symmetry.
(b) Majority of plant viruses have RNA as their genetic material. (Exception: Cauliflower Mosaic Virus has double stranded DNA as genetic material)
(c) Plant viruses cause disease in plants, e.g. Tobacco Mosaic Virus (TMV).
2. Animal virus:
(a) Generally, they are polyhedral in shape with radial symmetry.
(b) They have either DNA or RNA as genetic material.
(c) It causes disease to majority of animals including human beings, e.g. Influenza virus.
3. Bacteriophage:
(a) They have tadpole-like shape.
(b) They infect bacteria and hence are called as bacteriophage.
(c) Bacteriophages were discovered by Twort.
(d) Bacteriophages have double stranded DNA as the genetic material.
(e) Its body consists of head, collar and tail.
In simple words: Viruses are classified based on their host into plant, animal, and bacteriophages, each exhibiting distinct shapes, genetic material, and disease-causing patterns.

🎯 Exam Tip: When explaining virus classification, remember to specify the type of genetic material (DNA or RNA) and the typical shape for each category (plant, animal, and bacteriophage) as these are key differentiating features.

Question 7. Identify the following diagram, label it and write detail information in your words.
ℹ️ चित्र व्याख्या (Diagram Explanation): प्रश्न में विभिन्न जीव प्रकारों को दर्शाने वाले कई बिना लेबल वाले आरेख (A-F) शामिल हैं, जैसे कि फ्लैगेलेट (यूग्लीना), एक मोल्ड फंगस (म्यूकोर), एक सिलियाटेड प्रोटिस्ट (पैरामीशियम), एक बैक्टीरियोफेज वायरस, एक कोनिडिया बनाने वाला फंगस (एस्परगिलस), और एक मशरूम (एगेरिकस)। छात्र को प्रत्येक आरेख की पहचान करनी है, उसे लेबल करना है और उसके बारे में विस्तृत जानकारी लिखनी है।
Answer:
The given figure represents Bacteriophage.
A.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह यूग्लीना का एक नामांकित आरेख है, जिसमें एक फ्लैगेलम, माइटोकॉन्ड्रिया, नाभिक, क्लोरोप्लास्ट, गोल्गी उपकरण, न्यूक्लियोलस, एंडोप्लाज्मिक रेटिकुलम, संग्रहीत कार्बोहाइड्रेट, संकुचनशील रिक्तिका और फोटोरिसेप्टर जैसी प्रमुख संरचनाएं दिखाई गई हैं।
B.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह म्यूकोर का एक नामांकित आरेख है, जिसमें एक स्पोरैंगियम (बीजाणुधानी), स्पोरैंजियोफोर और हाइफ़ा जैसी संरचनाएं दिखाई गई हैं, जो इस फंगस के बीजाणु उत्पादन और वृद्धि के पैटर्न को दर्शाती हैं।
C.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह पैरामीशियम का एक नामांकित आरेख है, जिसमें मैक्रोन्यूक्लियस, माइक्रोन्यूक्लियस, खाद्य रिक्तिकाएं, साइटोपीज, गलेट, सिलिया, मौखिक खांचा, लाइसोसोम, ट्राइकोसिस्ट और संकुचनशील रिक्तिका जैसी प्रमुख संरचनाएं दिखाई गई हैं।
D.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक बैक्टीरियोफेज का नामांकित आरेख है, जिसमें सिर, कॉलर, कोर, म्यान, बेसप्लेट, पूंछ पिन और पूंछ फाइबर जैसी विशिष्ट टैडपोल जैसी संरचनाएं दिखाई गई हैं, जो इसके वायरस मोर्फोलॉजी को उजागर करती हैं।
E.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एस्परगिलस का एक नामांकित आरेख है, जिसमें एक कोनिडियोफोर पर कोनिडिया का निर्माण दिखाया गया है, जो इस फंगस की अलैंगिक प्रजनन संरचनाओं को दर्शाता है।
F.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एगेरिकस (मशरूम) का एक नामांकित आरेख है, जिसमें पाइलस (टोपी), हाइमेनियम (गलफड़े), एनुलस (रिंग), स्टाइप (डंठल) और वोल्वा (कप) जैसी प्रमुख संरचनाएं दिखाई गई हैं, जो इसके फलने वाले शरीर की विशेषता को दर्शाती हैं।
In simple words: This question requires identifying and labeling various biological diagrams, including protists (Euglena, Paramoecium), fungi (Mucor, Aspergillus, Agaricus), and a bacteriophage, and describing their key features.

🎯 Exam Tip: Practice drawing and labeling key biological diagrams is essential, focusing on the distinct morphological features and organelles that help identify each organism and its function.

Question 8. The scientific name of sunflower is given below. Identify the correctly written name.
(A) Helianthus annus
(B) Helianthus Annus
(C) Helianthus annuus L.
(D) Helianthus annuus I.
Answer: (C) Helianthus annuus L.
The correctly written scientific name of sunflower is Helianthus annuus L.
In simple words: The correct scientific name for sunflower is Helianthus annuus L., following binomial nomenclature rules where the genus is capitalized, species is lowercase, and a discoverer's initial may be appended.

🎯 Exam Tip: Remember the rules of binomial nomenclature: the genus name starts with a capital letter, the species name is all lowercase, both are italicized, and the author's abbreviation (e.g., L. for Linnaeus) is sometimes included but not italicized.

Question 9. Match the following.

Kingdom	Examples
1. Monera	a. Riccia
2. Protista	b. Cyanobacteria
3. Plantae	c. Rhizopus
4. Fungi	d. Diatoms

Answer:

Kingdom	Examples
1. Monera	b. Cyanobacteria
2. Protista	d. Diatoms
3. Plantae	a. Riccia
4. Fungi	c. Rhizopus

In simple words: This matching exercise links each of the four kingdoms (Monera, Protista, Plantae, Fungi) with a representative organism, reinforcing fundamental classification knowledge.

🎯 Exam Tip: Memorize key examples for each biological kingdom and phylum, as matching questions frequently test this direct recall of classification.

Question 10. Complete the following.
1. Plant-like Protista – [ ]
2. [ ] - Entamoeba
Answer:
1. Plant-like Protista – [Euglenoids/Dinoflagellates/Diatoms/Chrysophytes]
2. [Animal-like Protista (Protozoans)] - Entamoeba
In simple words: This question tests knowledge of protist diversity, requiring identification of examples for plant-like protists and the broader category to which Entamoeba belongs.

🎯 Exam Tip: When completing such questions, recall the major groups within Protista and their representative members, paying attention to their modes of nutrition or key characteristics.

Practical/Project:

Question 1. Make a group of students. Observe living organisms in your school/college campus and try to write their characters with respect to habit, habitat, mode of nutrition, growth- determinate or indeterminate, type of reproduction – vegetative reproduction, asexual reproduction, sexual reproduction. With the help of similarity and dissimilarity, try to classify organisms into different categories. Similar work should implement for animal group.
Answer:
The common living organisms observed near school/college are:
1. Plants
Habit: Herb, shrub, tree, etc.
Habitat: Terrestrial or aquatic
Mode of nutrition: Autotrophic
In simple words: This practical question encourages students to observe, characterize, and classify local living organisms based on their habit, habitat, nutrition, growth, and reproduction methods, promoting hands-on taxonomic understanding.

🎯 Exam Tip: For observation-based questions, structure your answer by clearly listing the characteristics (habit, habitat, nutrition, etc.) for each observed organism and highlighting how these features aid in classification.

 

Question 2.
Find out types of lichens and its economic importance.
Answer:
Types of lichens are:
1. Based on fungal components:
(a) Ascolichens:
In this category, the fungal partner belongs to Ascomycetes group of fungi.
(b) Basidiolichens:
Here, the fungal partner belongs to Basidiomycetes group of fungi.
(c) Deuterolichens:
In this category, the fungal partner belongs to Deuteromycetes group of fungi.
2. Based on their forms:
(a) Crustose lichen:
These lichens show crust-like growth.
These lichens grow on rocks and bark of the trees,
e. g. Graphis, Lecanora, Haematomma, etc.
(b) Foliose lichen:
These lichens grow on trees in the hilly regions.
The thallus is like a dry forked leaf,
e. g. Parmelia, Collema, Peltigera
(c) Fruticose lichen:
These lichens are seen on the branches of trees hanging down.
They are cylindrical, well branched and pendulous, with hair-like outgrowths,
e. g. Usnea, Cladonia, Alectoria, etc.
3. Economic importance of lichens:
(a) Lichen as food and fodder:
Many species of lichens are used as food by animals including man. Lichens contain a substance lichenin which is similar to carbohydrate making them edible. Parmelia is used in curry powder in India. Lichens like Cladonia, Citraria, Evernia, Parmelia are used as fodder as they form a favourite food for reindeers and cattles
(b) Lichens in medicine:
Lichens contain usnic acid due to which they are used in medicines. Usnea and Cladonia species are used as an antibiotic against Gram positive bacteria. Species like Lobaria, Citraria are useful in respiratory disease like T.B., Peltigera is useful in hydrophobia, Parmelia is used in treatment of epilepsy, whereas Usnea is used in urinary disease. Some lichens are also used in medicine due to their anticarcinogenic property.
(c) Industrial use of lichens:
1. Lichens are used in various dyes for colouring fabrics.
2. Species like Rocella and Lasallia are used in preparation of litmus paper which is acid-base indicator.
3. In Sweden and Russia, lichens are used for production of alcohol.
4. Orcein is a biological stain obtained from Orchrolechia androgyna and O. tortaria.
5. Some lichens are also used in tanning process in leather industry.
6. Evernia and Ramalina are the sources of essential oils which are used in preparation of soaps and other cosmetics.
(d) Other uses of lichens:
1. Lichens are used in cosmetics.
2. Some lichens like Everniaprunastri also known as oakmoss is used in making perfumes.
3. Lichen is also used as a preservative for beer.
In simple words: Lichens are symbiotic organisms classified by their fungal component and growth form. They have significant economic importance, serving as food, medicine (antibiotics, disease treatment), and in various industries (dyes, alcohol, tanning, cosmetics).

🎯 Exam Tip: When describing the economic importance of lichens, provide specific examples for each category (food, medicine, industry) to demonstrate comprehensive knowledge.

 

Can You Tell? (Textbook Page No. 7)

Enlist uses of taxonomy?
Answer:
Uses of taxonomy are as follows:
1. It is used to assign each organism an appropriate place in a systematic framework of classification.
2. It is used to group animals and plants by their characteristics and relationships.
3. It is used to classify organisms based upon their similarities and differences.
4. It is used for nomenclature of an organism. Assigning a name to an organism is essential for its identification without confusion throughout the scientific world.
5. It is used to serve as an instrument for identification of an organisms. A newly isolated organism can be placed to its nearest relative or can be identified as a new organism with unknown characteristics.
6. It becomes easier to understand the evolutionary trends in different groups of organisms.
In simple words: Taxonomy helps organize life by classifying organisms, assigning them unique names, identifying new species, and understanding their evolutionary relationships, which prevents confusion in the scientific community.

🎯 Exam Tip: Focus on clarity and conciseness when listing the uses of taxonomy; each point should highlight a distinct benefit of the classification system.

 

Can You Tell? (Textbook Page No. 7)

Which characters of organisms are visible characters?
Answer:
The visible characters of organisms include habit, colour, mode of respiration, growth, reproduction, etc.
In simple words: Visible characters are observable traits like an organism's physical appearance (habit, color), how it breathes, its growth pattern, and how it reproduces.

🎯 Exam Tip: When asked for visible characters, list features that can be observed externally or through simple, direct examination.

 

Can You Tell? (Textbook Page No. 7)

What is evolution?
Answer:
1. It is believed that the life originated on earth in its very simple form.
2. Constant struggle of the early living beings gave rise to more and more perfect forms of life.
3. This struggle and progress are evolution which led to formation of diverse life forms.
In simple words: Evolution describes the gradual development of life from simple to more complex and diverse forms over time, driven by constant change and adaptation.

🎯 Exam Tip: Define evolution by emphasizing its progressive nature and the emergence of diverse life forms from simpler origins.

 

Can You Tell? (Textbook Page No. 7)

What is DNA barcoding?
Answer:
DNA barcoding is a new method for identification of any species based on its DNA sequence, which is obtained from a tiny tissue sample of the organism under study.
In simple words: DNA barcoding is a technique that identifies species by analyzing short, standardized DNA sequences from a small tissue sample.

🎯 Exam Tip: Highlight "DNA sequence" and "species identification" as key elements when explaining DNA barcoding.

 

Can You Tell? (Textbook Page No. 7)

Name the recent approaches in taxonomy.
Answer:
The recent approaches in taxonomy includes:
1. Morphological Approach
2. Embryological Approach
3. Ecological Approach
4. Behavioral Approach / Ethological Approach
5. Genetical Approach / Cytological Approach
6. Biochemical Approch
7. Numerical Taxonomy
In simple words: Recent taxonomy uses diverse methods like studying an organism's form, development, environment, behavior, genetics, biochemistry, and numerical analysis for classification.

🎯 Exam Tip: Listing a good range of approaches demonstrates understanding of the multidisciplinary nature of modern taxonomy.

 

Can You Tell? (Textbook Page No. 9)

Make a flow chart showing taxonomic hierarchy.
Answer:
Kingdom - Sub-kingdom - Division / Phylum - Class - Cohort / Order - Family Genus - Species
In simple words: Taxonomic hierarchy organizes life from broad categories like Kingdom down to specific ones like Species, showing nested levels of classification.

🎯 Exam Tip: Ensure the correct order of the taxonomic ranks from broadest to most specific, as this is fundamental to understanding classification.

 

Do Yourself (Textbook Page No. 16)

Complete the table (given on textbook Page No.16) through collecting information about sunflower, tiger with characteristic features.
(i) Sunflower:

Category	Taxon	Characteristics
Kingdom	Plantae	Autotrophic, photosynthetic, cell wall present.
Sub-kingdom	Phanerogamae	Seed producing plants, reproductive structures are visible.
Division	Angiospermae	Seeds are enclosed within the fruit.
Class	Dicotyledonae	Two cotyledons, tap root system, reticulate venation, pentamerous symmetry of flower, vascular bundle open.
Order	Asterales	Capitulum inflorescence, showing ray florets and disc florets.
Family	Asteraceae	Aster family
Genus	Helianthus	-
Species	annuus	-

(ii) Tiger:

Category	Taxon	Characteristics
Kingdom	Animalia	Multicellular eukaryotes, cell wall absent, heterotrophic nutrition.
Phylum	Chordata	Notochord present
Class	Mammalia	Presence of mammary gland
Order	Carnivora	Carnivorous in nature
Family	Felidae	Cat-like mammals
Genus	Panthera	Large cats
Species	tigris	-

In simple words: This table categorizes Sunflower (a plant) and Tiger (an animal) using taxonomic ranks from Kingdom to Species, highlighting their distinguishing characteristics at each level.

🎯 Exam Tip: When completing taxonomic tables, ensure accurate spelling of scientific names and correctly match the characteristic features to their corresponding taxonomic ranks.

 

Can You Tell? (Textbook Page No. 9)

Why horse and ass are considered to be two different species or animals?
Answer:
1. Species is a group of organisms that can interbreed under natural conditions to produce fertile offsprings.
2. Horse and ass (donkey) are considered to be two different species or animals, because they cannot interbreed under natural condition to produce fertile offspring.
In simple words: Horses and asses are distinct species because, while they can mate, their offspring (mules or hinnies) are sterile, meaning they cannot produce fertile young naturally.

🎯 Exam Tip: The key criterion for defining separate species, especially in closely related animals, is the ability to produce fertile offspring.

 

Internet My Friend: (Textbook Page No. 9)

(i) Collect the information about most recent system of classification of living organisms and Kingdom System of Classification, e.g. Search for APG system of classification for Plants.
Answer:
[Note: Students are expected to collect more information about most recent system of classification of living organisms and Kingdom System of Classification from internet on their own.]
In simple words: Students should research current classification systems, like the APG system for plants, and gather details on the various kingdom classification approaches.

🎯 Exam Tip: For research-based questions, actively use reliable online sources to gather up-to-date and specific information, citing them if required.

 

Internet My Friend: (Textbook Page No. 9)

(ii) Collect the information about classification systems for all types of organisms.
Answer:
[Note: Students are expected to collect more information about classification systems for all types of organisms from internet on their own.]
In simple words: Students should investigate different classification systems applicable to all forms of life, using online resources to find comprehensive details.

🎯 Exam Tip: Organize collected information logically, perhaps by historical development or by the major groups of organisms covered by each system.

 

Can You Recall? (Textbook Page No. 6)

What is Five Kingdom system of classification?
Answer:
Five kingdom system of classification was proposed by R.H. Whittaker in 1969. This system shows the phylogenetic relationship between the organisms.
The five kingdoms are:
1. Kingdom Monera
2. Kingdom Protista
3. Kingdom Plantae
4. Kingdom Fungi
5. Kingdom Animalia
In simple words: The Five Kingdom system, proposed by R.H. Whittaker, classifies all living organisms into Monera, Protista, Fungi, Plantae, and Animalia, based on their evolutionary relationships.

🎯 Exam Tip: Remember the name of the scientist (R.H. Whittaker) and the year (1969), along with the correct list of the five kingdoms.

 

Can You Tell (Textbook Page No. 14)

Classify fungi into their types.
Answer:
Fungi are classified into four types on the basis of their structure, mode of spore formation and fruiting bodies as follows:
1. Phycomycetes:
Members of this class are commonly called as algal fungi.
These are consisting of aseptate coenocytic hyphae.
They grow well in moist and damp places on decaying organic matter as well as in aquatic habitats or as parasites on plants.
e.g. Mucor, Rhizopus (bread mold), Albugo (parasitic fungus on mustard).
2. Ascomycetes:
These are commonly called as sac fungi.
These are multicellular. Rarely they are unicellular (e.g. Yeast).
Hyphae are branched and septate.
They can be decomposers, parasites or coprophilous (grow on dung).
Some varieties of this class are consumed as delicacies such as morels and truffles.
Neurospora is useful in genetic and biochemical assays.
e.g. Aspergillus, Penicillium, Neurospora, Claviceps, Saccharomyces (unicellular ascomycetes).
3. Basidiomycetes:
These are commonly called as club fungi.
They have branched septate hyphae.
e.g. Agaricus (mushrooms), Ganoderma (bracket fungi), Ustilago (smuts), Puccinia (rusts), etc.
4. Deuteromycetes:
It is a group of fungi which are known to reproduce only asexually.
They are commonly called imperfect fungi.
They are mainly decomposers, while few are parasitic, e.g. Alternaria.
In simple words: Fungi are categorized into Phycomycetes, Ascomycetes, Basidiomycetes, and Deuteromycetes, based on their cellular structure, reproductive methods, and how they form spores and fruiting bodies.

🎯 Exam Tip: For each fungal class, focus on a key distinguishing feature (e.g., coenocytic hyphae for Phycomycetes, sac-like asci for Ascomycetes) and provide one or two common examples.

 

Can You Tell? (Textbook Page No. 14)

Write a note on economic importance of fungi.
Answer:
Economic importances of fungi are as follows:
1. Role of fungi in medicine:
(a) Antibiotic penicillin is obtained from Penicillium.
(b) Drugs like cyclosporine, immunosuppressant drugs, precursors of steroid hormones, etc are isolated from fungi.
2. Role of fungi in industries:
(a) Yeast is used in bread making. It causes dough to rise and make the bread light and spongy. It is also used in breweries or wine making industries. Sugars present in grapes are fermented by using yeast. This results in production of alcohol which is used for making wine.
(b) Lichen is a symbiotic association of algae and fungi are used in preparation of litmus paper which is used as acid-base indicator.
3. Role of fungi in food:
(a) Fungi like mushrooms are consumed as a food. These are rich source of protein.
(b) Fungi genus Penicillium helps in ripening of cheese.
4. Role of fungi as biocontrol agents:
(a) Fungi help to control growth of weeds.
(b) Pathogenic fungi like Fusarium sp., Phytophthorapalmivora, Alternaria crassa, etc act as mycoherbicides.
In simple words: Fungi are economically important for medicine (antibiotics, drugs), industry (bread, wine, litmus), food (mushrooms, cheese), and as biocontrol agents against weeds and pathogens.

🎯 Exam Tip: When detailing economic importance, ensure a balanced representation across different sectors like medicine, industry, food, and environmental applications, providing specific examples for each.

 

Can You Tell? (Textbook Page No. 14)

Why are fungi considered as heterotrophic organisms?
Answer:
In fungi, chloroplast is absent, thus they cannot synthesize their own food by photosynthesis. Fungi decompose the organic matter by breaking down with the help of enzymes from which they absorb nutrients. Thus, exhibiting heterotrophic mode of nutrition.
In simple words: Fungi are heterotrophic because they lack chloroplasts and cannot photosynthesize; instead, they absorb nutrients by decomposing organic matter using enzymes.

🎯 Exam Tip: The core reason for fungi's heterotrophic nature is the absence of chloroplasts and their mode of nutrition via absorption of decomposed organic matter.

 

Can You Tell? (Textbook Page No. 14)

What are coenocytic hyphae?
Answer:
1. In filamentous fungi, body consists of mycelium which is formed by a network of hyphae.
2. When these hyphae are non-septate, multinucleated, they are known as coenocytic hyphae.
In simple words: Coenocytic hyphae are fungal filaments that lack internal cross-walls (non-septate) and contain multiple nuclei within a continuous cytoplasm.

🎯 Exam Tip: Define coenocytic hyphae by highlighting the two key characteristics: "non-septate" (lacking cross-walls) and "multinucleated."

 

Can You Tell? (Textbook Page No. 14)

(i) How are fungi different from plants?
Answer:
Fungi are different from plants because:
(a) They lack chloroplast hence, do not perform photosynthesis and are heterotrophic in nutrition. Whereas plants are autotrophic and prepare their own food by photosynthesis.
(b) They are separated from Plantae based on their saprophytic mode of nutrition.
(c) Fungi are decomposers of ecosystem whereas plants are producers of ecosystem.
(d) In fungi, cell wall is made up of fungal cellulose or chitin. Whereas in plants, cell wall is made up of cellulose and pectic compounds.
In simple words: Fungi differ from plants primarily by lacking chloroplasts, making them heterotrophic decomposers with chitin cell walls, unlike plants which are autotrophic producers with cellulose cell walls.

🎯 Exam Tip: Focus on fundamental biological differences like nutrition mode, cell wall composition, and ecological role when comparing fungi and plants.

 

Can You Tell? (Textbook Page No. 14)

(ii) Have you seen any diseased plant in your farm?
Answer:
Yes, I have seen some diseased plants in our farm.
There are different pathogens like fungi, bacteria, viruses that cause diseases in plants.
The common plant diseases are:
(a) Leaf rust disease: It is caused by fungus Puccinia triticina. It is the most common rust disease of wheat.
(b) Blight disease in rice: It is caused by harmful bacteria Xanthomonas oryzae. It causes wilting of seedlings and yellowing and drying of leaves.
(c) Early blight of potato: It is caused by fungi Alternaria solani. It causes 'bulls eye' patterned leaf spots and tuber blight on potato.
(d) Crown gall disease: It is caused by Agrobacterium tumefaciens. This pathogen infects the plant and forms rough surfaced galls on stem and roots.
[Students are expected to write their observations about diseased plants found informs]
In simple words: Yes, diseased plants are common, affected by pathogens like fungi, bacteria, and viruses, leading to conditions such as leaf rust, blight, early blight, and crown gall disease, all of which damage plant health.

🎯 Exam Tip: When answering about plant diseases, mention common pathogens and provide at least two specific examples of diseases with their causative agents and symptoms.

 

Can You Tell? (Textbook Page No. 14)

Complete the following table:
Answer:

Plantae	Animalia
1. Autotrophic mode of nutrition.	Heterotrophic mode of nutrition.
2. They do not show locomotion.	They show locomotion.
3. Cell wall is present.	Cell wall is absent.
4. Chloroplast present.	Chloroplast absent.
5. They do not possess nervous system.	They possess well developed nervous system, i
6. Reproduction can be both sexual and asexual.	Mainly shows sexual reproduction.

In simple words: This table highlights key differences between Plantae and Animalia, focusing on nutrition (autotrophic vs. heterotrophic), locomotion (absent vs. present), cell walls (present vs. absent), chloroplasts (present vs. absent), nervous systems (absent vs. present), and reproductive methods.

🎯 Exam Tip: When completing comparison tables, ensure each point contrasts a specific feature directly between the two groups, maintaining parallel structure.

 

Can You Tell? (Textbook Page No. 15)

Why are viruses called infectious nucleoproteins?
Answer:
1. Viruses are acellular, highly infectious and ultramicroscopic.
2. Viruses possess their own genetic material in the form of either DNA or RNA, but never both. The genetic material in viruses is covered by a protein coat (capsid), hence called nucleoprotein.
3. They do not show any activity outside the body of host but once they enter their specific host cell, they start multiplying within the living host cells.
4. Viruses lack their own metabolic machinery, they make use of the cellular machinery of the host i.e. ribosome for the synthesis of protein during their reproduction and therefore, they cause severe infection. Thus, they are called infectious nucleoproteins.
In simple words: Viruses are called infectious nucleoproteins because they consist of genetic material (nucleic acid) encased in a protein coat (capsid), and they are obligate parasites that infect host cells to reproduce.

🎯 Exam Tip: Emphasize the two main components (nucleic acid and protein coat) and their parasitic nature within host cells to explain why viruses are termed "infectious nucleoproteins."

 

Can You Tell? (Textbook Page No. 15)

Describe genetic material in plant and animal viruses as well as in bacteriophages.
Answer:
The genetic material in different viruses is as given below:
1. Plant virus: (b) Majority of plant viruses have RNA as their genetic material. (Exception: Cauliflower Mosaic Virus has double-stranded DNA as genetic material)
2. Animal virus: (b) They have either DNA or RNA as genetic material.
3. Bacteriophage: (d) Bacteriophages have double-stranded DNA as the genetic material.
In simple words: Plant viruses mostly have RNA, animal viruses can have either DNA or RNA, and bacteriophages typically contain double-stranded DNA as their genetic material.

🎯 Exam Tip: For each virus type, state the primary genetic material and note any significant exceptions, such as Cauliflower Mosaic Virus in plants.

 

Can You Tell? (Textbook Page No. 15)

Differentiate between viruses and viroids.
Answer:

Viruses	Viroids
1. They have high molecular weight.	They have low molecular weight.
2. They are larger in size.	They are smaller in size.
3. They can infect plant, animals and bacteria.	They mainly infect plants.
4. The genetic material can be ss-RNA, ds-RNA or DNA.	The genetic material is single stranded circular RNA.
5. Protein coat is present.	Protein coat is absent.
6. mosaic disease is a plant disease caused by viruses.	Tomato chloric dwarf is a plant disease caused by viroids.

In simple words: Viruses are larger, have a protein coat, can infect plants, animals, and bacteria, and contain various forms of nucleic acids; viroids are smaller, lack a protein coat, primarily infect plants, and consist solely of single-stranded circular RNA.

🎯 Exam Tip: When differentiating, focus on key structural components (protein coat), genetic material type, size, and host range as critical distinguishing features.

 

Internet My Friend. (Textbook Page No. 15)

In modern medicine, certain infectious neurological diseases were found to be transmitted by abnormally folded proteins. These proteins are called prions. The word prion comes from 'proteinaceous infectious particle', e.g. mad cow disease in cattle, Jacob's disease in human.
Find more information about prions.
Answer:
Prions:
1. A prion is a misfolded form of a protein generally present in brain cells.
2. When the prion gets into a cell containing the normal form of the protein, the prion somehow converts normal protein molecules to the misfolded prion versions.
3. Several prions then aggregate into a complex that can convert other normal proteins to prions.
4. Prions can be transmitted through blood, surgical instruments and contaminated food.
5. Diseases caused by prions are Bovine Spongiform Encephalopathy in cattles, Kuru and Creutzfeldt - Jakob disease in humans.
[Note: Students are expected to search for more information about Prions on internet]
In simple words: Prions are infectious agents made of misfolded proteins that can convert normal proteins into their aberrant form, leading to neurological diseases like mad cow disease and Creutzfeldt-Jakob disease.

🎯 Exam Tip: When discussing prions, highlight their proteinaceous nature, their ability to induce misfolding in normal proteins, and name specific neurological diseases they cause.