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NCERT Solutions for Class 11 Biology Chapter 2 – Biological Classification

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NCERT Solutions for Class 11 Biology Chapter 2 Biological Classification: The chapter on Biological Classification is important for students approaching the home exams. This article introduces NCERT solutions designed to help students explain the concepts of further learning and how to write to get good grades on exams. The NCERT Solutions for Class 11 Biology are presented in very simple language for ease of understanding.

NCERT CBSE Chapter 2 Biological Classification for Class 11 explains the arrangement of the organisms in hierarchical series of groups and subgroups. Revise the basic concepts of Biological Classification for quick revision and class notes.

Q1: Discuss How Classification Systems Have Undergone Several Changes Over a Period of Time?

Answer:

The procedure of arranging or grouping organisms in hierarchical series of groups and sub-groups is known as Biological Classification. Previously, Aristotle discovered artificial system of classification. On the basis of habitat it is divided into two types- animals and plants. For example – Aerial (birds), aquatic (whales, fish) and terrestrial (cattle, reptiles). The factors which is used to classify organisms are Morphology, physiology, ontogeny, anatomy and reproduction. It is based on numerical taxonomy, cladistic taxonomy, cytotaxonomy and chemotaxonomy.

Q2: State Two Economically Important Uses of:

  • (a) Heterotrophic bacteria
  • (b) Archaebacteria

Answer:

(a) The Two important uses of heterotrophic bacteria are:

  • They help in the nitrogen-fixing in the atmosphere.
  • They are used in the production of curd, butter, cheese and so on.

(b) The Two important uses of Archaebacteria are:

  • Archaebacteria are used in bioleaching of mines.
  • They are used in the biogas production. They can be found in the guts of ruminants like cows and buffaloes.

Q3: What is the Nature of Cell Walls in Diatoms?

Answer:

The cell wall is made up of cellulose which has been embedded with silica, imparting the patterns onto the walls. They are also known as frustules. They are made up of two overlapping halves which fit together like the two halves of a petri dish. They produce large mounds of diatomite at the bottom of water reservoirs. Generally fine patterns are found on the outer layers.

Q4: Find Out What Do the Terms ‘Algal Bloom’ and ‘Red Tides’ Signify?

Answer:

Algal bloom are the overgrowth of algae and other phytoplankton(cyanobacteria). They are found in contaminated water, which leads to water pollution. They breathe in carbon dioxide and breathe out oxygen. Rise in nitrate levels, a mineral ion required for bacterial and algal growth causes algal blooms. Red tides are defined as the process of fast multiplication of red-pigmented dinoflagellates, which gives the sea a red color. Some of these create toxins which harms the fish and invertebrates, or they can also accumulate in food chains which create risks in human who eats shellfish or any other seafoods.

Q5: How Are Viroid Different From Viruses?

Answer:

Viroid are tiny when it is compared with viruses. Viroid are the small infectious agents which consists of single stranded RNA  without the protein coat whereas viruses consists of single-stranded or double-stranded RNA bound with protein-coat. Viroid can infect only the plants whereas viruses can infect plants, animals, mammals and microorganisms.

Q6: Describe Briefly the Four Major Groups of Protozoa.

Answer:

Protozoa are heterotrophic in nature, they are found as predator or parasites. They are classified as:

  1. Amoeboid Protozoans: These protozoa are found in seawater, fresh water or moist soil. They move and catch their prey using pseudopodia (false feet).
  2. Flagellated Protozoans: They are the free-living parasitic protozoans. They have flagella for locomotion purpose. Trypanosoma, a parasitic form causes disorders like sleeping sickness.
  3. Ciliated Protozoans: They are aquatic organisms with thousands of cilia, which help them move. They have a cavity on the surface which opens to the outside.
  4. Sporozoans: They are the parasitic organisms which go through the life cycle which includes spore stage. Plasmodium create harmful effect in humans as it causes malaria.

Q7: Plants Are Autotrophic. Can You Think of Some Partially Heterotrophic Plants?

Answer:

Carnivores and Insectivores plant are partially known as heterotrophic, these types of organisms are autotrophic. They kill a variety of insects to gain nitrogen from them. Examples – Nepenthes, Utricularia.

Q8: What Do the Terms Phycobiont and Mycobiont Signify?

Answer:

Lichen are the organized objects which is made up of an algae and fungus which are permanently associated. Phycobiont are the algal component and mycobiont are the fungal component of lichen. They both are the parts of symbiotic relationship where the fungus is the dominant partner and algae are the submissive ones. The structural covering which the fungus provided protects algae from heat and other environmental factors.

Q9: Give a Comparative Account of the Classes of Kingdom Fungi Under the Following:

  • a) mode of nutrition
  • b) mode of reproduction

Answer: 

Class of fungi

Phycomycetes

Ascomycetes

Basidiomycetes

Deuteromycetes

Mode of nutrition

Parasitic or saprophytic Parasitic, saprophytic or decomposers Saprophytic Parasitic, saprophytic or decomposers

Mode of reproduction

Sexual reproduction- zygote can similar or different in morphology.

Asexual reproduction done by zoospore and aplanospore.

Sexual spores are known as ascospores and asexual sopores are known as conidia The mode of reproduction is vegetation reproduction through budding. Reproduction is done by asexual spores called conidia.

Q10: What Are the Characteristic Features of Euglenoids?

Answer:

The characteristic features of Euglenoids are:

  • Euglenoids are photoautotrophic or holophytic on their feeding.
  • Asexual reproduction are used by longitudinal binary fission.
  • Euglenoids consists of flagellates with one cell.
  • They doesn’t consist of a well defined cell wall.
  • Euglenoids consists of two types of cytoplasm – Endoplasm and Ectoplasm.

Q11: Give a Brief Account of Viruses With Respect to Their Structure and Nature of Genetic Material . Also Name Four Common Viral Diseases.

Answer:

Viruses are the infectious agent which are nucleoproteins which have one or more nucleic acids in together. They are crystalline in structure and are found outside the host cell. They are located within the protein core due to that the genetic material is either DNA or RNA but never both of them together. If the virus which infects the plants consists of single stranded, then the virus which infect the animal will be single or double-stranded DNA or RNA. The two sections of virus are nucleoid and capsid. Capsid is the protein coat which is made up of small subunits called capsomers. Four examples of common viral diseases- AIDS, Influenza, Rabies and Herpes.

 

VIRUS.jpg

Structure of a bacteriophage (viruses that infect bacteria) and virus

 

Q12: Organise a Discussion in Your Class on the Topic- Are Viruses Living or Non-living?

Answer:

Viruses consists of some features which shows their living nature while other shows their non-living nature. It can be living or non-living and tough to tell that whether they are dead or alive.

Living nature of viruses

  • They have the ability to multiply.
  • Mutations occur.
  • Presence of genetic material.
  • They are host specific.
  • They consists of antigen properties.

Non-living nature of viruses

  • They are stored in bottles like crystals.
  • They don’t have cellular structure.
  • They cannot grow outside the host.

Also Check:

FAQ’s on NCERT Solutions for Class 11 Biology Chapter 2

Q1. What advantages come from utilizing NCERT Solutions for Chapter 2 of Class 11 Biology?

Using NCERT Solutions for Class 11 Biology Chapter 2 offers several advantages:

1. Accurate Solutions Aligned with Current CBSE Guidelines

2. Valuable Aid for Board Exam Preparation

3. Organized in Chapterwise and Exercise-specific Formats

4. Free Downloadable PDF Format Solutions

5. Step-by-Step Answers Tailored to CBSE Exam Weightage Criteria

Q2. Which key concepts in NCERT Solutions for Class 11 Biology Chapter 2 are particularly important for the exam?

The critical exam-relevant concepts in NCERT Solutions for Class 11 Biology Chapter 2 include:

  1. Kingdom Monera
  2. Kingdom Protista
  3. Kingdom Fungi
  4. Kingdom Plantae
  5. Viruses, Viroids, Prions, and Lichens

Q3. What are the distinctive characteristics of Euglenoids as discussed in Chapter 2 of NCERT Solutions for Class 11 Biology?

In Chapter 2 of NCERT Solutions for Class 11 Biology, Euglenoids exhibit the following distinctive features:

1. Lack of a cell wall.

2. Presence of pellicles, providing flexibility to their body.

3. Presence of two flagella of different lengths.

4. They demonstrate heterotrophic behavior in the absence of sunlight and switch to autotrophic mode in the presence of sunlight.

Q4. How can students benefit from the CBSE Free PDF Download available through online free resources for their studies?

Students can benefit significantly from the CBSE Free PDF Download available through online free resources by accessing study materials, textbooks, and other educational resources at no cost. These PDFs can serve as valuable supplements to their learning, enabling them to review, practice, and deepen their understanding of various subjects and topics. It offers a convenient and accessible way to study and prepare for exams without the need for physical textbooks, making it a cost-effective and flexible option for students seeking quality educational materials.



Last Updated : 11 Sep, 2023
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