Questions: Biological Classification

Q1 State the main criteria used by Whittaker for his five kingdom classification.

Answer: Whittaker used five criteria. Cell structure separated prokaryotes from eukaryotes. Body organisation separated single cells from many-celled bodies. Mode of nutrition separated autotrophs from heterotrophs and absorbers. Reproduction gave another set of differences. Phylogenetic relationships asked which groups share descent. On these criteria he named Monera, Protista, Fungi, Plantae and Animalia.

Hinglish: Whittaker ne cell structure, body organisation, nutrition, reproduction aur phylogenetic relationships ko criteria banaya. Inhi ke aadhar par Monera, Protista, Fungi, Plantae aur Animalia banaye.

Q2 Why was the two kingdom system found inadequate?

Answer: The two kingdom system put prokaryotes and eukaryotes together, mixed single-celled organisms with many-celled ones, and placed photosynthetic green algae in the same kingdom as non-photosynthetic fungi because both had a wall. Many organisms did not fit either kingdom at all. Once cell structure and wall chemistry were studied, the flaws became impossible to defend.

Hinglish: Do kingdom system mein prokaryote aur eukaryote ek saath the, unicellular aur multicellular bhi mix ho gaye, aur green algae fungi ke saath plant kingdom mein chale gaye. Bahut organism kisi bhi kingdom mein fit nahi hote the, isliye system badalna pada.

Q3 Describe the shapes of bacteria with one example of each kind.

Answer: Bacteria are sorted by shape into four kinds. The coccus is round, and a chain of cocci is a common form. The bacillus is rod-shaped, and the tubercle bacterium is an example. The vibrio is comma-shaped, as in the cholera bacterium. The spirillum is spiral, as in the bacterium that causes rat-bite fever. Shape is a first step, and cell arrangement gives more detail.

Hinglish: Bacteria chaar shapes ke hote hain: round coccus, rod bacillus, comma vibrio aur spiral spirillum. Shape dekhkar pehla classification hota hai, phir cell arrangement dekha jaata hai.

Q4 How are archaebacteria different from eubacteria, and why does it matter?

Answer: Archaebacteria have a different cell wall structure, and that difference lets them live in extreme places such as very salty ground, hot springs and marshy areas. Eubacteria have the usual rigid wall and, when motile, a flagellum. The wall chemistry is the reason archaebacteria survive conditions that kill other bacteria, and it is also why they are separated in classification.

Hinglish: Archaebacteria ki cell wall alag hoti hai, isliye woh salty areas, hot springs aur marshy jagahon par survive karte hain. Eubacteria ki wall normal rigid hoti hai aur motile hone par flagellum hota hai. Yahi wall chemistry unhe alag banati hai.

Q5 Write the economic importance of cyanobacteria and of heterotrophic bacteria.

Answer: Cyanobacteria fix atmospheric nitrogen in heterocysts, so they enrich the soil and are used in agricultural fields. Heterotrophic bacteria decompose dead matter, turn milk into curd, produce antibiotics, and fix nitrogen inside the root nodules of legumes. A few heterotrophic species cause disease, but the useful roles are the ones the chapter lists first.

Hinglish: Cyanobacteria ke heterocysts nitrogen fix karte hain, isliye yeh soil ki fertility badhate hain. Heterotrophic bacteria dead matter decompose karte hain, milk se curd banate hain, antibiotics banate hain aur legume roots mein nitrogen fix karte hain.

Q6 Describe the diatoms and explain why their walls are special.

Answer: Diatoms are microscopic chrysophytes with a wall built of two overlapping halves, fitted like a soap box. Silica is embedded in the wall, so it is hard and nearly indestructible. When the cells die, the walls settle in the habitat and collect over billions of years as diatomaceous earth. That earth is gritty and is used for polishing and for filtering oils and syrups. Diatoms are also major producers in the oceans.

Hinglish: Diatoms ke wall do overlapping halves se bante hain, soap box ki tarah, aur usme silica hota hai jo wall ko bahut hard banata hai. Unki dead walls se diatomaceous earth banti hai, jo polishing aur filtration mein kaam aati hai. Diatoms ocean ke chief producers hain.

Q7 Name the four groups of protozoans and give one example of each.

Answer: Amoeboid protozoans move and feed with pseudopodia; Amoeba is the example. Flagellated protozoans move with flagella; Trypanosoma is the example. Ciliated protozoans move with cilia and steer food into a gullet; Paramoecium is the example. Sporozoans have an infectious spore-like stage; Plasmodium is the example.

Hinglish: Amoeboid protozoans pseudopodia se chalte hain, jaise Amoeba. Flagellated protozoans flagella use karte hain, jaise Trypanosoma. Ciliated protozoans cilia se chalte hain, jaise Paramoecium. Sporozoans mein spore stage hoti hai, jaise Plasmodium.

Q8 Explain the sexual cycle of a fungus with the dikaryophase.

Answer: The cycle starts with plasmogamy, the fusion of the protoplasms of two compatible hyphae. In ascomycetes and basidiomycetes the two nuclei do not fuse at once, so the cell enters a dikaryophase in which each cell holds two haploid nuclei. Karyogamy then fuses the nuclei into a diploid nucleus. Meiosis in the fruiting body follows, and the result is haploid spores. In other fungi, karyogamy follows plasmogamy without a dikaryophase.

Hinglish: Fungal sexual cycle plasmogamy se shuru hoti hai, phir ascomycetes aur basidiomycetes mein dikaryophase aata hai jisme har cell mein do alag haploid nuclei rehte hain. Uske baad karyogamy se nuclei fuse hote hain aur meiosis se haploid spores bante hain.

Q9 Compare the four classes of fungi on spore type and mycelium.

Answer: Phycomycetes have an aseptate coenocytic mycelium, asexual zoospores or aplanospores, and a sexual zygospore. Ascomycetes have a septate mycelium, asexual conidia, and sexual ascospores inside asci. Basidiomycetes have a septate mycelium, usually no asexual spores, and sexual basidiospores on a basidium. Deuteromycetes have a septate mycelium, asexual conidia, and no known sexual stage.

Hinglish: Phycomycetes aseptate coenocytic mycelium aur zygospore rakhte hain. Ascomycetes mein septate mycelium, conidia aur ascospores hote hain. Basidiomycetes mein basidiospores basidium par bante hain aur asexual spores aam taur par nahi hote. Deuteromycetes ki sexual stage pata nahi hoti, sirf conidia milte hain.

Q10 Why are viruses kept outside the five kingdoms, and what is a viroid?

Answer: A virus is not made of cells, so it does not fit any kingdom that is defined by cellular organisation. Its particle is a nucleoprotein with a protein capsid around one nucleic acid. It is inert outside a host and multiplies only inside a living cell, which makes it an obligate parasite. A viroid is an infectious agent even smaller than a virus. It is free RNA with no protein coat, and its RNA is of low molecular weight. Diener found the first viroid as the cause of potato spindle tuber disease.

Hinglish: Virus cell se bana nahi hota, isliye five kingdoms mein nahi aata. Woh nucleoprotein hai jo host ke bahar inert rehta hai aur andar hi multiply karta hai. Viroid virus se bhi chhota hai, sirf free RNA hai jisme protein coat nahi hota, aur uski RNA low molecular weight ki hoti hai. Diener ne potato spindle tuber disease mein ise khoja.

That completes the ten written answers. The five-question quiz below checks the kingdom criteria, the groups of protists and fungi, and the structure of a virus.