Question 1

Q1: What are the difficulties that you would face in classification of animals, if common fundamental features are not taken into account?

Accepted Answer

If common fundamental features such as level of organisation, symmetry, nature of coelom, segmentation, and presence of notochord were not taken into account, the classification of animals would face several significant difficulties: 1.  Lack of a Scientific Basis: The classification would become ar...

Question 2

Q10: How important is the presence of air bladder in Pisces?

Accepted Answer

The presence of an air bladder is very important, and it is a key distinguishing feature between the two main classes of fishes (Pisces): Chondrichthyes (cartilaginous fishes) and Osteichthyes (bony fishes).    In Osteichthyes (Bony Fishes): The air bladder is present. Its primary function is to reg...

Question 3

Q11: What are the modifications that are observed in birds that help them fly?

Accepted Answer

Birds (Class Aves) exhibit several significant modifications that are adaptations for flight: 1.  Presence of Feathers: Feathers provide insulation, but more importantly, they create the aerodynamic surfaces of the wings and tail necessary for lift and steering during flight. 2.  Modification of For...

Question 4

Q12: Could the number of eggs or young ones produced by an oviparous and viviparous mother be equal? Why?

Accepted Answer

No, the number of eggs produced by an oviparous mother and the number of young ones produced by a viviparous mother are generally not equal. Oviparous mothers typically produce a much larger number of offspring. Here is why:    Oviparous Animals (Egg-laying): These animals, like fishes, amphibians,...

Question 5

Q13: Segmentation in the body is first observed in which of the following: (a) Platyhelminthes (b) Aschelminthes (c) Annelida (d) Arthropoda

Accepted Answer

The correct answer is (c) Annelida. According to the chapter, animals in the Phylum Annelida are the first to exhibit true metameric segmentation. The text states, "They are triploblastic, metamerically segmented and coelomate animals. Their body surface is distinctly marked out into segments or met...

Question 6

Q14: Match the following: (a) Operculum	(i) Ctenophora (b) Parapodia	(ii) Mollusca (c) Scales	(iii) Porifera (d) Comb plates	(iv) Reptilia (e) Radula	(v) A...

Accepted Answer

Here is the correct matching based on the characteristics described in the chapter:    (a) Operculum matches with (viii) Osteichthyes. (The operculum is the gill cover in bony fishes.)    (b) Parapodia matches with (v) Annelida. (Parapodia are lateral appendages for swimming in aquatic annelids like...

Question 7

Q15: Prepare a list of some animals that are found parasitic on human beings.

Accepted Answer

Based on the examples given in the chapter, here is a list of animals that are parasitic on human beings: 1.  Phylum Platyhelminthes (Flatworms):        Taenia (Tapeworm) - An endoparasite in the intestines.        Fasciola (Liver fluke) - An endoparasite in the liver. 2.  Phylum Aschelminthes (Roun...

Question 8

Q2: If you are given a specimen, what are the steps that you would follow to classify it?

Accepted Answer

To classify a given animal specimen, I would follow a systematic approach by examining its fundamental features in a hierarchical order, as described in the chapter: 1.  Level of Organisation: First, I would determine the level of body organisation. Is it at the cellular level (like sponges), tissue...

Question 9

Q3: How useful is the study of the nature of body cavity and coelom in the classification of animals?

Accepted Answer

The study of the nature of the body cavity and coelom is very useful and serves as a fundamental basis for the classification of animals, particularly for triploblastic organisms. The presence or absence of a coelom and its type helps in distinguishing major animal phyla. 1.  Primary Level of Classi...

Question 10

Q4: Distinguish between intracellular and extracellular digestion?

Accepted Answer

Question 11

Q5: What is the difference between direct and indirect development?

Accepted Answer

The difference between direct and indirect development lies in whether a larval stage is present during the life cycle of an organism. Direct Development: In direct development, there is no intermediate larval stage. The young ones that hatch from an egg or are born are essentially miniature version...

Question 12

Q6: What are the peculiar features that you find in parasitic platyhelminthes?

Accepted Answer

Parasitic platyhelminthes (flatworms) show several peculiar features and adaptations for their parasitic mode of life. Based on the chapter, these features include: 1.  Hooks and Suckers: Many parasitic forms possess specialized structures like hooks and suckers. These are used for attaching firmly...

Question 13

Q7: What are the reasons that you can think of for the arthropods to constitute the largest group of the animal kingdom?

Accepted Answer

Arthropods constitute the largest phylum of the animal kingdom, with over two-thirds of all named species on Earth. The reasons for their immense success and diversity can be attributed to several key features mentioned in the chapter: 1.  Chitinous Exoskeleton: They possess a hard, protective, and...

Question 14

Q8: Water vascular system is the characteristic of which group of the following: (a) Porifera (b) Ctenophora (c) Echinodermata (d) Chordata

Accepted Answer

The correct answer is (c) Echinodermata. As stated in the section on Phylum Echinodermata, "The most distinctive feature of echinoderms is the presence of water vascular system which helps in locomotion, capture and transport of food and respiration."

Question 15

Q9: "All vertebrates are chordates but all chordates are not vertebrates". Justify the statement.

Accepted Answer

This statement is correct and can be justified by understanding the classification of Phylum Chordata. The fundamental characteristics of all chordates, present at some stage of their life, are: 1.  Presence of a notochord. 2.  A dorsal, hollow nerve cord. 3.  Paired pharyngeal gill slits. Phylum Ch...

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