Questions: The Living World

Q1 What is meant by living? Give four defining features of life forms.

Answer: Living means having a cellular organisation in which metabolic reactions run and the organism responds to its surroundings. Four defining features are used in the chapter. Growth, which happens by cell division rather than by adding material on the outside. Reproduction, by which the species continues even though a single individual may not reproduce. Metabolism, the sum of all building and breaking reactions inside the cell, which no living organism lacks. Consciousness, the ability to sense the environment and react to it, which separates the living from the non-living most clearly.

Hinglish: Living hone ka matlab hai cellular organisation ke andar chal rahi metabolism ki reactions aur environment ke prati response. Chaar features yaad rakho: growth jo cell division se hoti hai, reproduction jo species ko aage badhati hai, metabolism jiska koi exception nahi, aur consciousness jo living aur non-living ka sabse clear farq batati hai.

Q2 How does growth in a living organism differ from the growth of a crystal or a snowball?

Answer: A living organism grows from inside. Its cells divide and the number of cells rises, so the new material is built by the organism itself. A crystal grows when material from the solution settles on its surface, and a snowball grows when snow sticks to the outside. The size increases in all three cases, but only the living form shows growth by cell multiplication. That is why a biologist does not accept size alone as proof of life.

Hinglish: Living organism andar se badhta hai, kyunki uske cells divide hokar number badhate hain. Crystal ya snowball bahar se material jodkar bada hota hai. Size sab jagah badhta hai, par growth by cell division sirf living mein hoti hai.

Q3 Is reproduction essential for a living organism? Explain with an example.

Answer: Reproduction is not essential for the survival of an individual. A mule is sterile and cannot produce young ones, yet it is a living animal. Worker bees do not reproduce, and many people never have children. What reproduction does is keep the species going from one generation to the next. Biologists therefore treat it as a property of the species rather than a condition that every individual must meet.

Hinglish: Reproduction individual ke bachne ke liye zaroori nahi hai. Mule sterile hai phir bhi living hai, worker bees reproduce nahi karti, aur bahut log bachche paida nahi karte. Reproduction species ko aage badhata hai, isliye ise species ki property maano, har individual ki shart nahi.

Q4 Why is metabolism called a defining feature of life without exception?

Answer: Metabolism is the set of chemical reactions by which a living cell builds and breaks molecules. These reactions go on in every living cell, including a seed that looks dormant, because a seed still carries out slow chemical work. When the cell's organisation is lost, the reactions stop and the organism is dead. That is why metabolism, rather than movement or growth, is treated as the feature that no living organism lacks.

Hinglish: Metabolism woh chemical reactions hain jinse cell molecules banata aur todta hai. Sookha lagne wala seed bhi dhime chemical kaam karta rehta hai, isliye usme bhi metabolism hota hai. Jab cell ki organisation khatam ho jaati hai to reactions ruk jaati hain. Isliye metabolism ka koi exception nahi hai.

Q5 What is the need for a standard system of naming organisms?

Answer: Local names differ from region to region, and one local name may stand for two different plants. A record kept under local names cannot be shared or checked across regions. A standard scientific name under a written code gives one organism one accepted name everywhere, so that a worker in any country can tell which species is meant. The code also ensures that a name used for one organism has not been used for another.

Hinglish: Local naam har region mein badal jaate hain, aur ek naam do alag plants ke liye bhi chal sakta hai. Isliye scientific name chahiye jo poore world mein same ho. Code yeh bhi sunishchit karta hai ki ek naam kisi doosre organism ne pehle se use na kiya ho.

Q6 State four rules that govern the writing of a scientific name.

Answer: Biological names are written in Latin or are Latinised from other languages. They are printed in italics; when handwritten, each of the two words is underlined separately. The first word, the genus, begins with a capital letter and the second word, the specific epithet, begins with a small letter. The author who first described the species is cited at the end of the name in an abbreviated form, as in Mangifera indica Linn.

Hinglish: Scientific naam Latin ya Latinised form mein likha jaata hai. Print mein italics, haath se likhne par dono words alag underline. Genus ka pehla letter capital, specific epithet ka small. Original scientist ka naam end mein abbreviation ke roop mein aata hai, jaise Mangifera indica Linn.

Q7 Distinguish between identification, classification and nomenclature.

Answer: Identification is the step that finds out which known taxon a specimen belongs to. Classification places organisms into groups by their shared characters. Nomenclature gives each organism a standard scientific name under the rules of the code. The three steps are linked in practice: a specimen is described, identified, placed in its group, and then named. Characterisation comes before all three because it produces the description on which the other steps rely.

Hinglish: Identification batati hai ki specimen kis known taxon ka hai. Classification organisms ko shared characters ke basis par groups mein rakhti hai. Nomenclature standard scientific naam deti hai. Pehle characterisation se description banti hai, phir baaki teen steps chalte hain.

Q8 Define a taxon and show that the same word can refer to different ranks.

Answer: A taxon is a group of organisms treated as a unit of classification at some rank. The same organism belongs to several taxa at once. A dog is a taxon at the species level as Canis familiaris, a taxon at the genus level as Canis, and a member of the taxon Canidae at the family level. The group called animals and the group called mammals are also taxa, but at different ranks, and both contain the dog.

Hinglish: Taxon kisi rank ka group hota hai. Ek hi organism kai taxa mein aata hai: dog species level par Canis familiaris, genus level par Canis, aur family level par Canidae ka member hai. Animals ka group aur mammals ka group bhi taxon hain, par alag ranks par.

Q9 Describe the taxonomic hierarchy with an example of a plant and an animal.

Answer: The hierarchy runs from species at the bottom upward through genus, family, order, class, phylum or division, to kingdom. For mango, the sequence is Mangifera indica, Mangifera, Anacardiaceae, Sapindales, Dicotyledonae, Angiospermae. For man, it is Homo sapiens, Homo, Hominidae, Primata, Mammalia, Chordata. As the ranks rise, the number of shared characters falls and the group covers more organisms.

Hinglish: Hierarchy species se shuru hokar genus, family, order, class, phylum ya division, aur kingdom tak jaati hai. Mango par rank ke saath naam lo: species Mangifera indica, phir genus Mangifera, family Anacardiaceae, order Sapindales, class Dicotyledonae, division Angiospermae. Man par: species Homo sapiens, genus Homo, family Hominidae, order Primata, class Mammalia, phylum Chordata. Upar jaate hi shared characters kam hote hain.

Q10 Why do classification systems change from time to time?

Answer: A classification system is a model of relationships built from the evidence available. New species are discovered, older specimens are studied again, and molecular methods reveal differences that shape and anatomy hide. Each new piece of evidence can move a group or split one. The system therefore changes with better evidence, and the change is a sign that the model is being tested rather than a fault in the method.

Hinglish: Classification ek model hai jo available evidence par bana hota hai. Naye species milte hain aur molecular methods se woh differences dikhte hain jo bahar se nahi dikhte. Isliye groups badalte hain. System ka badalna galti nahi, balki evidence ke saath model ka improve hona hai.

That completes the ten written answers. The five-question quiz below checks the features of life, binomial naming and the order of the taxonomic ranks.