Questions: Animal Kingdom

Q1 Explain the levels of organisation with examples.

Answer: Sponges have the cellular level, where cells form loose aggregates with some division of labour. Coelenterates reach the tissue level, because cells doing the same work form tissues. Platyhelminthes and the higher phyla reach the organ level, because tissues group into organs with specialised jobs. Annelids, arthropods, molluscs, echinoderms and chordates reach the organ system level, where organs join into systems such as the gut or the circulatory system.

Hinglish: Cellular level sponges mein hota hai, jahan cells loose aggregate banate hain. Tissue level coelenterates mein, organ level Platyhelminthes aur upar, aur organ system level annelids se chordates tak milta hai.

Q2 What is the difference between open and closed circulatory systems?

Answer: In an open system the heart pumps blood out into spaces, and the cells and tissues are bathed directly in it. In a closed system the blood stays inside vessels of different diameters, the arteries, veins and capillaries. Arthropods and most molluscs have an open system, while annelids and chordates have a closed one. A closed system gives faster and more directed transport, which is an advantage for active animals.

Hinglish: Open system mein blood heart se nikal kar direct cells ke aas paas aata hai, jaise arthropods mein. Closed system mein blood vessels ke andar rehta hai, jaise annelids aur chordates mein. Closed system transport zyada tez aur directed karta hai.

Q3 Distinguish between diploblastic and triploblastic animals.

Answer: A diploblastic animal has two embryonic layers, an outer ectoderm and an inner endoderm, with the undifferentiated mesoglea between them. Coelenterates are the standard example. A triploblastic animal adds a third layer, the mesoderm, between ectoderm and endoderm. Platyhelminthes up to chordates are triploblastic. The third layer allows a true coelom, muscles and complex organs to develop.

Hinglish: Diploblastic mein do germ layers hote hain, ectoderm aur endoderm, beech mein mesoglea, jaise coelenterates mein. Triploblastic mein teesri layer mesoderm aati hai, jaise Platyhelminthes se chordates tak. Teesri layer se coelom aur muscles ban paate hain.

Q4 Describe the water transport system of a sponge and its uses.

Answer: Water enters a sponge through the ostia in the body wall and reaches the central spongocoel. From there it leaves through the osculum. Choanocytes, the collar cells that line the spongocoel and the canals, keep the current moving and trap food particles. The same current carries oxygen in and wastes out. Food gathering, respiration and waste removal therefore all run on one water flow.

Hinglish: Sponge mein paani ostia se andar, spongocoel mein, aur osculum se bahar jaata hai. Choanocytes current banate hain aur food pakadte hain. Yahi flow respiration aur waste removal bhi karta hai.

Q5 What is metagenesis? Give the example named in the chapter.

Answer: Metagenesis is the alternation of the polyp and medusa forms in a cnidarian life cycle. The polyp produces medusae asexually, and the medusae produce polyps sexually. The two forms thus alternate, and Obelia is the example printed in the chapter. The polyp is fixed and cylindrical while the medusa is umbrella-shaped and free-swimming.

Hinglish: Metagenesis mein polyp aur medusa do forms alternate karte hain: polyp asexually medusa banata hai aur medusa sexually polyp. Obelia iska example hai. Polyp fixed hota hai aur medusa tairta hai.

Q6 Why are Platyhelminthes called acoelomate, and what special structures help them as parasites?

Answer: Platyhelminthes are acoelomate because no cavity separates the body wall from the gut wall. Their parasitic members carry hooks and suckers for attaching to the host tissue, and some absorb nutrients directly through the body surface instead of through a gut. Flame cells handle osmoregulation and excretion, and the body is flattened so that it fits inside host tissues.

Hinglish: Platyhelminthes mein body cavity nahi hoti, isliye woh acoelomate hain. Parasitic forms mein hooks aur suckers attachment ke liye hote hain, kuch nutrients body surface se absorb karte hain, aur flame cells osmoregulation karti hain.

Q7 Give the three fundamental characters of chordates and one extra feature.

Answer: The three fundamental characters are a notochord, a nerve cord that is dorsal and hollow, and gill slits in pairs along the pharynx. A tail that runs past the anus is an additional chordate character, and a closed circulatory system is also present. In a vertebrate the notochord gives way to a cartilaginous or bony vertebral column later, though the embryo still shows the notochord.

Hinglish: Chordata ke teen characters hain: notochord, dorsal hollow nerve cord aur paired pharyngeal gill slits. Iske alawa post-anal tail aur closed circulatory system bhi hota hai. Vertebrates mein notochord ki jagah adult mein vertebral column aa jaata hai.

Q8 How does a cartilaginous fish differ from a bony fish?

Answer: A cartilaginous fish has a skeleton of cartilage, placoid scales, gill slits without an operculum, a persistent notochord and no air bladder, so it must keep swimming. A bony fish has a bony skeleton, cycloid or ctenoid scales, gills covered by an operculum and an air bladder that controls buoyancy. Most cartilaginous fishes are marine, while bony fishes live in both sea water and fresh water.

Hinglish: Cartilaginous fish mein cartilage skeleton, placoid scales, operculum nahi, notochord life bhar, aur air bladder nahi hota, isliye unhe lagatar tairna padta hai. Bony fish mein bony skeleton, cycloid/ctenoid scales, operculum aur air bladder hota hai jo buoyancy control karta hai.

Q9 Compare amphibians and reptiles on skin, heart and development.

Answer: Amphibians have moist skin without scales, a three-chambered heart, and external fertilisation with indirect development. A reptile carries dry cornified skin with epidermal scales or scutes, three heart chambers in most species but four in the crocodile, and fertilisation inside the body followed by direct development. Reptiles are fully terrestrial in their reproduction, while amphibians need water for their eggs and larvae.

Hinglish: Amphibians ki skin moist aur scales ke bina hoti hai, heart three-chambered, fertilisation external aur development indirect. Reptiles ki skin dry cornified scales wali hoti hai, heart aam taur par three-chambered par crocodile mein four, fertilisation internal aur development direct. Amphibians ko eggs aur larvae ke liye paani chahiye.

Q10 Why are mammals considered the most adapted vertebrates?

Answer: Mammals occupy habitats from polar ice to deserts, forests, caves and water, and some have taken to flight. Their young are fed on milk from mammary glands, the skin has hair and the external ears are present. The four-chambered heart, lungs and a warm-blooded body let them hold a steady temperature in cold and heat, and different kinds of teeth allow a varied diet. Most are viviparous, which protects the embryo inside the mother.

Hinglish: Mammals polar ice se desert, forest, cave aur paani tak har jagah rehte hain, kuch udte bhi hain. Mammary glands se bachchon ko doodh milta hai, skin par hair hoti hai, aur pinnae bahar dikhte hain. Four-chambered heart aur warm-blooded body temperature control karte hain, aur viviparity embryo ko maa ke andar protect karti hai.

That completes the ten written answers. The five-question quiz below checks the classification characters, the phyla and the vertebrate classes.