Biological classification Class 11 Introduction
Biological classification Class 11:- In the living world identification and categorisation of characteristics and grouping them on the basis of their features is known as biological Classification.
Earlier,
- Linnaeus categories or classify into two i.e plantae and animalia.
After that,
- R.H Whitaker in 1969 gave the five kingdoms of classification, i.e Monera, protista, fungi, plantae, animalia.
Classification of the living organisms undergo various changes over the time.
Biological classification Class 11 – Very Short Answer Type Questions
Q.1. Give the advantages of the five-kingdom classification over the two-kingdom classification.
A.1. Following are the advantages of five kingdom classification over two-kingdom classification:
- It is based upon cell structure
- It is based upon the body structure
- Nutrition
- Way of living
- Phylogenetic relationship
Q.2. Give the reason why cyanobacteria are used in agricultural fields for crop improvement.
A.2. Cyanobacteria have the ability to fix atmospheric nitrogen and make it available to the plants. It improves the crop yield. This is the only reason why cyanobacteria are used in agricultural fields.
Q.3.Write examples of insectivorous plants.
A.3. Examples of insectivorous plants: Venus flytrap, pitcher plants, butterworts, sundews, and other members of the Bromeliaceae.
Q.4. Give the similarities a virus and non-living objects share.
A.4. A virus is considered living inside the host but non-living when outside the host. The reason is:
- Having inert nature.
- They have an inability to reproduce.
- Absence of cellular organization.
- It cannot grow and divide.
Q.5. Give the reason why do polluted water bodies have an abundance of Nostoc and Oscillatoria?
A.5. Nostoc and Oscillatoria are enhanced by the nutrients present in the polluted water bodies.
Q.6. Write the name of eukaryotic kingdoms in the five-kingdom classification proposed by Whittaker.
A.6. The eukaryotic kingdoms in the five-kingdom classification are following:
- Protista
- Fungi
- Animalia
- Plantae
Q.7. Write the nature of the cell wall of diatoms.
A.7. The diatom cell wall forms two thin overlapping cells. It is made up of silica.
Q.8. By whom Five-kingdom classification is proposed ?
A.8. Robert Whittaker proposed the five-kingdom classification i.e Monera, Protista, Fungi, Plantae and Animalia.
Q.9. Write the difference between a virus and a viroid.
A.9. A virus contains DNA or RNA as a genetic material and a protein coat whereas the viroids do not have a protein coat but RNA as genetic material.
Q.10. What are the uses of heterotrophic bacteria and archaebacteria which are economically important?
A.10.Following are the uses of:
Heterotrophic Bacteria
- It maintain the fertility of the soil by fixing nitrogen, ammonification and nitrification. Eg., Rhizobium
- The milk products such as cheese, curd are obtained by bacteria.
Archaebacteria
- Methanogens produces biogas from animal dung.
Biological classification Class 11 Quiz
Q.11. Chemosynthetic bacteria are autotrophic or heterotrophic?
A.11. Autotrophs.
Q.12.Write the example of parasitic plants.
A.12. There are around 4,000 identified species of parasitic plants.
Few examples of parasitic plants are Corpse Flower, birds’ nest, orchid and dodder.
Biological classification Class 11 – Short Answer Type Questions
Q.1 Define diatomaceous earth. Give the reason why diatoms referred to as ‘pearls of the ocean’?
A.1. The accumulation of large deposits of diatoms that forms a covering of silica extending over several 100m for billions of years. It is the main producer in the ocean. Diatoms prepare food for themselves as well as other organisms formed in the ocean. Their body is made up of a siliceous shell known as a frustule.
Q.2. Describe the myth of ‘fairy rings’ created by the mushrooms after heavy rains in the forest.
A.2. Mushroom mycelium absorbs the nutrients from the soil.In the centre nutrients get exhausted and grow in diameter thereby forming a circle. These rings are known as fruiting bodies of the fungus and are called ‘fairy ring’.
Q.3. Why Neurospora is an important genetic tool?
A.3. Neurospora can be easily grown under laboratory conditions by adding organic salts, carbohydrates and vitamins. Under X-ray treatments, mutations can be inserted easily in the Neurospora cells and meiotic division is easily visible.
Q.4. What is the role of fungi in our daily lives?
A.4. Following are the role of fungi in our daily life :
- Few fungi such as Agaricus compestris are very highly rich in nutrients and it is used as food.
- The saprophytic fungi act on dead and decaed matter and convert the complex substances into simpler ones that are absorbed by the plants in the form of nutrients.
- Some fungi possess soil binding capacity and make the soil good for cultivation. For eg., Mucor, Absidia, etc.
- It provides resistance against pests.
- For the preperation of alcohol and yeast, fungi are used due to their fermentation property. For eg., Saccharomyces
Q.5. What are the features of Trypanosoma make it fall under the kingdom Protista?
A.5.Following are the reasons that Tryanosoma falls under the kingdom protista:
- It is unicellular.
- Nucleus is centrally located and the endosome is contained by nucleus.
- Granulated reserve food material .
- Mode of reproduction asexual by binary fission.
Q.6Fruiting bodies produced by Ascomycetes like apothecium, perithecium, or cleistothecium. Give the differences between these three fruiting bodies?
A.6.
| Apothecium | Perithecium | Cleistothecium |
| cup-shaped structure. It is lichens ascigerous fruitification . Eg., Peziza | flask-shaped structure. Eg., Neurospora | It is closed to ascocarp. Eg., Penicillin |
Q.7. Cyanobacteria and heterotrophic bacteria are different from each other but comes under eubacteria of the kingdom Monera. Is this type of grouping justified?
A.7. They have few similarities that’s why they are introduced in the same Kingdom:
- They don’t possess a well-defined nucleus.
- DNA lies free in the cytoplasm.
- 70S ribosomes type present.
- The nucleolus and a nuclear membrane absent in nucleus.
Q.8. Define Parasitic plants.
A.8. The plant which depends on other plants and animals for their food and nutrition are known as parasitic plants. Cuscuta and Cassytha are the examples of parasitic plants.
Q.9. What is ‘phycobiont’ and ‘mycobiont’?
A.9. The algal part of the lichens is known as phycobiont, while the fungal part is known as mycobiont. Both the algae and the fungi stay in symbiotic association with each other. The algae prepare food for the fungi and the fungi, in return, provides shelter and absorbs nutrients from the soil.
Q.10. Viruses are living or non-living explain.
A.10. Viruses are the connecting link between the living and the non-living. The features that classify them as living and non-living are given below:
Living
- It possess a non-cellular organization.
- It is inactive outside of the body of a host.
- Lack of respiration
cell metabolism absent.
- It can be crystallized and precipitated.
Non-living
- It possess genetic material.
It can undergo mutation.
- It can grow and multiply inside the host body .
- It is an obligate parasite and attacks specific hosts.
Biological classification Class 11 Toppers Notes
Q.11.What is Insectivorous plants?
A.11. Plants that absorb or gain their nutrients from trapping and consuming insects and other arthropods or protozoans,are called insectivorous plants or Carnivorous plants. Acidic bogs is the best examples of insectivorous plants.
Q.12.Name some plants that are partially heterotrophic.
A.12. Partial heterotrophs are given below:
- Loranthus and Viscum are partial stem parasites with the leathery leaves. With the help of haustoria they draw sap from xylem tissue of several fruits and forests tree .
Biological classification Class 11 – Long Answer Type Questions
Q.1. Give a note on the asexual reproduction by spores in algae.
A.1. Asexual reproduction of the algae involves the formation of several kinds of spores.
- Zoospores- Motile i.e movable naked spores with two, four or many flagella. For eg., Chlamydomonas bears biflagellate zoospores, Ulothrix bears quadriflagellate zoospores and Oedogonium bears multiflagellate zoospores.
- Aplanospores- They are non-motile. They may be formed singly or by the division of protoplast to develop several aplanospores. They are formed inside the sporangium during unfavourable conditions. Eg., Microspora.
- Tetraspores- Tetraspores are formed by diploid plants of some algae. They are a special type of haploid aplanospores formed within tetrasporangium.
- Akinetes- They are thick-walled spore-like structures with abundant food reserves. They can be survive under unfavourable conditions.
- Exospores- They are separated from the mother cell by the formation of the septum. They are formed near the end of the mother cell of the organism. Eg., Chamaesiphon
- Endospores- The mother protoplasm divides and forms the endospores. They are also known as conidia or gonidia. They are formed to survive under unfavourable conditions. Eg., Dermocarpa
Q.2. Write the characteristic features of euglenoids.
A.2. The characteristic features of euglenoids are:
- They are unicellular protista commonly present in freshwater.
- The cell membrane is full of proteins and is known as a pellicle.
- Two flagella present on the anterior end of the body.
- They possess light-sensitive eyespot.
- They are autotrophic due to the presence of photosynthetic pigment chlorophyll. However, in the absence of light, they behave as heterotrophs.
- They are the connecting-link between plants and animals because they possess features common to both plants and animals.
Biological Classification Class 11 Weightage in NEET
Q.3. How ‘peat’ naturally formed?
A.3. Peat is formed by the partial decomposition of organic matter in wetlands such as marshes and swamps.The warm and moist or humid climatic conditions facilitate the development of peat. The main producers of peat Sphagnum mostly occur in bogs. This plant gets accumulated over a period of time and gets hardened thereby converting into peat. It is used for the production of ethyl alcohol, tar, ammonia, etc. It is also used for the purpose of covering roots during transportation.
Q.4. List out the various algae and fungi that have commercial values in medicines, food, and chemicals.
A.4.
Algae:
| Medicines | Food | Chemicals |
| Corollina-cures worm infection | Porphyra, Rhodymenia, Chondrus | Phycolloids- includes agar, carageen in and funori |
| Polysiphonia- antibacterial property | Laminaria, Alariam, Macrocystis, sargassum | Alginic acid- phycocolloid obtained from laminaria |
| Sodium laminarin sulphate- coagulant | Edible brown algae used as fodder | Nerocystis, fucus, sargassum |
| Chlollera, Cualerpa- antibiotic extraction | Chlamydomonas, Chlollera, Scenedesmus-sewage oxidation | |
| Durvillea- Vermifuge properties | Ulva, Caulerpa, Enteromorpha | Ointments, toothpaste, creams, cosmetics, etc. |
| Ascophyllum- antibiotic properties | Used as salts in obtaining emulsions |
Fungi:
| Medicines | Food | Chemicals |
| Penicillin | Aspergillus oryzae- fermentation, Saccharomyces roxii- yeast | Aspergillus niger |
| Baccatin-A | Monoasus purpureus-food colourings | Aspergillus niger and P.purpurogenum |
| Penicillium citrinin | Penicillium camembert, Penicillin roqueforti-cheese production | Awentil and Mucur- production of citric acid |
| Claviceps purpurea | P.glacum, A.gallomyces |
Q.5.Define Taxonomy.
The branch of science that deals with the nomenclature, identification, descriptions and classification of all living organisms including animals, birds, insects, microbes and plants are termed Taxonomy. The classification is mainly based on their different Characterization, behaviour, identification, variations, genetics, etc.
All living organisms are distributed into different categories or levels including- Kingdom, Phylum, Class, Order, Family, Genus and Species.
Biological classification Class 11 Notes
Q.6. What are the benefits of five kingdom classification?
A.6. The benefits of the five-kingdom classification are:
- It is more scientific, accurate and natural.
- In this system of classification all living organisms are classified into different groups based on their similarities.
- It helps to learn more in detail about the phylogeny and evolutionary history of organisms.
Q.7.What are the types of bacteria there?
A.7. Bacteria are present in pairs, chains or clusters and also some species exist as single cells. There are different types of bacteria and they are classified based on their shapes, gram stain and their oxygen demand.
Based on their shapes, bacterias are classified into 5 groups:
1.Rod-shaped bacteria called as the bacilli. 2.Spiral shaped bacteria called as the spirilla.
3.Comma shaped bacteria called as the vibrios. 4.spherical shaped bacteria called as the cocci. 5.Corkscrew-shaped bacteria called as the spirochaetes.
On the basis of composition of their cell wall, bacterias are classified into 2 groups:
- Gram-positive bacteria.
- Gram-negative bacteria.
On the basis of mode of respiration or their oxygen demand, bacterias are classified into 2 groups:
- Aerobic bacteria or Aerobe
- Anaerobic bacteria or Anaerobe
On the basis of mode of nutrition, bacteria are classified into 2 groups:
- Autotrophic Bacteria
- Heterotrophic Bacteria
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