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Mice and Diplococcus pneumoniae.

Griffith used mice for his experiment.

(b) flask shaped

Blast of paddy, rust of wheat, red rot of sugarcane and white rust of crucifers.

Fungal Diseases in Humans:

The Salient Features Of Cyanobacteria: 

• The members of this group are prokaryotes and lack motile reproductive structures.
• The thallus is unicellular in Chroococcus, colonial in Gloeocapsa and filamentous trichome in Nostoc.
• Gliding movement is noticed in some species (Oscillatoria).
• The protoplasm is differentiated into central region called centroplasm and peripheral region bearing chromatophore called chromoplasm.
• The photosynthetic pigments include cphyocyanin and c-phycoerythrin along with myxoxanthin and myxoxanthophyll.
• The reserve food material is cyanophycean starch.
• In some forms a large colourless cell is found in the terminal or intercalary position called heterocysts. They are involved in nitrogen fixation.
• They reproduce only through vegetative methods and produce akinetes (thick wall dormant cell formed from vegetative cell), hormogonia (a portion of filament get detached and reproduce by cell division), fission and endospores.
• The presence of mucilage around the thallus is characteristic feature of this group. Therefore, this group is also called Myxophyceae.
• Sexual reproduction is absent.
• Microcystis aeruginosa and Anabaena flosaquae cause water blooms and release toxins and affect the aquatic organism. Most of them fix atmospheric nitrogen and are used as biofertilizers (Example: Nostoc and Anabaena). Spirulina is rich in protein hence it is used as single cell protein.

Alfatoxin, Patulin and Ochratoxin – A.

Features of Ascomycetes:

1. Ascomycetes include a wide range of fungi such as yeasts, powdery mildews, cup fungi, morels and so on. 

2. Although majority of the species live in terrestrial environment, some live in aquatic environments both fresh water and marine. 

3. The mycelium is well developed, branched with simple septum. 

4. Majority of them are saprophytes but few parasites are also known. (Powdery mildew – Erysiphe). 

5. Asexual reproduction takes place by fission, budding, oidia, conidia and chlamydospore. 

6. Sexual reproduction takes place by the fusion of two compatible nuclei.

7. Plasmogamy is not immediately followed by karyogamy, instead a dikaryotic condition is prolonged for several generations. 

8. A special hyphae called ascogenous hyphae is formed. 

9. A crozier is formed when the tip of the ascogenous hyphae recurves forming a hooked cell. The two nuclei in the penultimate cell of the hypha fuse to form a diploid nucleus. This cell form young ascus.

10. The diploid nucleus undergo meiotic division to produce four haploid nuclei, which further divide mitotically to form eight nuclei. The nucleus gets organised into 8 ascospores. 

11. The ascospores are found inside a bag-like structure called ascus. Due to the presence of ascus, this group is popularly called “Sac fungi”. 

12. Asci gets surrounded by sterile hyphae forming fruit body called ascocarp. 

13. There are 4 types of ascocarps namely Cleistothecium (Completely closed), Perithecium (Flask shaped with ostiole), Apothecium (Cup shaped and open type) and Pseudothecium.

In basidiomycetes the basidium is club shaped with four basidiospores, thus this group of fungi is popularly called “Club fungi”. The fruit body formed is called Basidiocarp.

Four Types Of Ascocarps Produced By Ascomycetes: 

1. Cleistothecium 

2. Perithecium 

3. Apothecium and

4. Pseudothecium.

1. Entamoeba histolytica causes amoebiasis 

2. Plasmodium vivax – causes malaria.

After synthesising their own proteins and creating numerous replica of their own type, then the virus destroys the host cells.

Producers, consumers and decomposers are the types of living organisms according to their lifestyle.

Absence of nuclear membrane, well- formed nucleus and lack of cell organelles are the characteristics of the prokaryotic cells.

1. Viruses are extremely minute of the size range of 10 nrn to 100 nm. They are on the borderline of living and non-living. They are 10 to 100 times smaller than bacteria and are visible only through the electron microscope. 

2. Though they are not considered as living, they can make replica of their own. 

3. They exist in the form of independent particles. They are long molecules of DNA or RNA which are covered by a protein coat.

4. Their survival is possible only inside the living plant or animal cells. When they infect the host cells, they produce their own proteins with the machinery of the host cell. These proteins form many replicas of the infecting virus. 

5. This infection destroys the host cell and the virus replicas are released. These free replicas re-infect the other adjoining cells of the host. 

6. Most of the viruses are pathogenic, they cause diseases in plants and animals.

• Bacteria: Kingdom Monera 
• Protozoa: Kingdom Protista 
• Fungi: Kingdom Fungi
• Algae: If unicellular, Kingdom Protista. If multicellular, Kingdom Plantae 
• Prokaryotic: Kingdom Monera 
• Eukaryotic: Any kingdom other than Monera. 
• Microbes: Kingdom Monera or Protista.

National Institute of Virology, Pune

(i) Biological classification.

(ii) Fungi.

(iii) saprotrophic.

(iv) saprotrophic.

(v) Bacteriophage.

(vi) Chitin.

Viruses, Bacteria, Fungi, Algae.

Classification is essential to achieve following needs:

1. To relate things based on common characteristic features. 

2. To define organisms based on the salient features. 

3. Helps in knowing the relationship amongst different groups of organisms. 

4. It helps in understanding the evolutionary relationship between organisms.

Robert Heinrich Hermann Koch is considered as the founder of modern bacteriology. He identified the causal organism for Anthrax. Cholera and Tuberculosis. He proved experimental evidence for the concept of infection (Koch’s postulates).

Five kingdom Classification:

1. The classification is based on the complexity of cell structure and organization of thallus. 

2. It is based on the mode of nutrition. 

3. Separation of fungi from plants. 

4. It shows the phylogeny of the organisms.

Correct option is (a) Monera

In Kingdom Monera bacteria were included but not viruses. Viruses are on the border line of living and non-living. Do we really call them living? If they are making replicas of their own type, are they not considered as living? Throughout the world they spread hazardous epidemics. Antibiotics do not act on viral particles. However, bacteria can be controlled by antibiotics. All the living organisms belonging to Monera are with prokaryotic cell. They do not have nuclear membrane and neither they have cell organelles. But a nice nucleus is seen in Euglena. Euglena is autotrophic protist. The fungi with cell wall of chitin are saprotrophic in their mode of nutrition.

1. All the living organisms belonging to Kingdom Monera are unicellular. 

2. The mode of nutrition in them is either autotrophic or heterotrophic. 

3. All of them are prokaryotic and thus they do not have well-formed nucleus. The nuclear membrane and the cell organelles are absent in them. 

4. Kingdom Monera consists of different types of bacteria and blue-green algae.

E.g. Bacteria Clostridium titani, Vibrio choleri, Treponema pallidum, Streptococcus pneumoniae, Legionella pneumoniae, Salmonella typhi, Staphylococcus aureus, Clostridium botulinum.

Correct option is (b) Blue-green algae

Between Photolithotrophs and Photoorganotrophs: 

1. Photolithotrophs: In photolithotrophs, the hydrogen donor is an inorganic substance. 

E.g. Chlorobium

2. Photoorganotrophs: In Photoorganotrophs, the hydrogen donor is an organic acid or alcohol. 

E.g. Rhodospirillum

Deoxyviruses and Riboviruses: 

1. Deoxyviruses: Viruses having DNA are called deoxyviruses. 

E.g. Animal viruses except HIV 

2. Riboviruses: Viruses having RNA are called riboviruses. 

E.g. Plant viruses except cauliflower mosaic virus (CMV)

Correct option is (a) Fungi

(a) The kingdom Monera and Protista accommodate both autotrophic and heterotrophic organisms, cell wall lacking and cell wall bearing organisms thus making these two groups more heterogeneous. 

(b) Viruses were not included in the system.

(d) Cavalier – Smith

Three kingdom classification was proposed by Haeckel.

The change is brought by Lactobacillus lactis, a bacterium present in the curd. The sourness is due to the formation of lactic acid.

R.H. Whittaker proposed the five kingdom classification. It includes Monera, Protista, Fungi, Plantae and Animalia.

Thomas Cavalier – Smith proposed six kingdom classification.

The kingdom includes: 

1. Archaebacteria 

2. Eubacteria 

3. Protista 

4. Fungi 

5. Plantae and 

6. Animalia.

I. Merits of Whittaker’s classification:

1. The classification system that Whittaker has adapted is totally based on scientific foundation. 

2. Prokaryotes are placed separately in a different kingdom. The prokaryotic organisms are different from other organisms, thus placing them separately is justified. 

3. All unicellular eukaryotic organisms are clubbed together in one kingdom named, Protista. This has helped to solve the placement of Euglena. 

4. Euglena has chloroplasts like plants but as animals it has flagella and thus there was conflict about such species during previous classification systems. It was placed in protozoa previously. 

5. Fungi are saprophytic and hence they are placed separately in a unique kingdom. 

6. According to five kingdom classification, the cell structure, organization of cell, mode of nutrition, lifestyle and phylogenetic relationship are taken into consideration. 

7. Therefore the system of 5 kingdom classification becomes most authentic system of biological classification.

II. Demerits of Whittaker’s method of classification: 

1. Some organisms belonging to Monera and Protista have ability to perform photosynthesis. Thus they show mode of nutrition as autotrophic, while others are heterotrophic. Similarly some monerans have cell wall and some Protists also have cell wall. This becomes confusing during their placement.

2. In kingdom Protista, organisms show varied characteristics. In spite of this they are placed together. 

3. In kingdoms, Plantae, Animalia and Fungi the organisms having primitive characters and were initial examples during evolution are not included. E.g. In Kingdom Animalia, amoeba is not included though it is said to be unicellular animal. This creates confusion. 

4. Similarly if algae are unicellular, they are placed in kingdom Protista and if they are multicellular they are placed in kingdom Plantae. In reality, unicellular and multicellular algae both show much similarity. But due to Whittaker’s classification system they are placed away from each other. 

5. Species of algae such as Chlorella, Chlamydomonas are not included in Kingdom Protista.

6. Viruses are not included in any of the kingdoms by Whittaker. Their classification has become a point of debate among the biologists.

Monera is the only prokaryotic kingdom in Whittaker’s classification, whereas protista, fungi, plantae and animalia comes under eukaryotes.

1. Herbarium is a dried plant specimen that is pressed, treated and mounted on a standard size sheet in order to preserve it. 

[Note: Herbarium is a collection of dried, pressed and labelled plant specimens arranged by a classification system.]

2. The essentials of a good herbarium are as follows: 

(i) It is essential to identify and label the collected specimen correctly.

(ii) Specimens should be stored in a dry place. 

(iii) The plants are usually pressed and mounted on the sheet of paper known as herbarium sheets. Some plants are not suitable for pressing or mounting, like succulents, seeds, cones, etc. They need to be preserved in suitable liquid like formaldehyde, acetic alcohol, etc.

(iv) In order to preserve the specimen for longer durations, acid-free paper, special glues and inks must be used to mount the specimen so that the specimen does not deteriorate.

Parvo viruses have ssDNA.

(b) Cauliflower mosaic virus

(d) Methanobacterium

Botanical gardens are places where plants of different varieties collected from different parts of the world are grown in vivo in a scientific and systematic manner. 

1. Greenhouse is a structure with suitable walls and a roof in which plants are grown under regulated climatic conditions. 

2. Most botanical gardens exhibit ornamental plants which require stringent/ optimum climatic conditions for their growth and/or flowering. 

3. The greenhouse associated with botanical gardens are also used to grow and propagate those plants that may not survive seasonal changes.

(b) Endospores

Viruses are considered as biological puzzle since they exhibit both living and non – living characters.

No, we cannot call reproduction as an inclusive character of life. Certain organisms like mules and worker bees do not reproduce and are still living. Thus, reproduction cannot be considered as an all inclusive defining characteristic of living organisms.

Growth, reproduction, metabolism, nutrition, movement and irritability, etc.

Metabolism can be considered as an all-inclusive (defining) feature of life since it is exhibited by all living organisms and does not take place in nonliving things. Another all-inclusive characteristic of life is responsiveness or irritability. This is a unique property of living beings since all living beings are conscious of their surroundings.

No, we cannot call reproduction as an inclusive character of life. Certain organisms like mules and worker bees do not reproduce and are still living.

Thus, reproduction cannot be considered as an all inclusive defining characteristic of living organisms.

(a) The sum total of all the chemical reactions occurring in the body is known as metabolism and no non-living object exhibits metabolism. 

(b) However, metabolic reactions can be demonstrated outside the body in a test tube (cell free medium). 

(c) Thus, isolated metabolic reaction (s) outside the body of an organism, performed in a test tube is neither living nor non-living. 

(d) Metabolic reactions occurring in vitro are living reactions but not living things.