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(b) Wallago allu

(b) All vertebrates are chordates

(b) Pharyngeal gill slits

(b) crocodile

Invertebrates:

• The major group of animals which do not have notochord or vertebral column are Invertebrates. 
• These are lower animals.

Vertebrates: 

• The major group of animals which have vertebral column are vertebrates 
• These are higher animals.

Invertebrates: 

• The major group of animals which do not have notochord or vertebral column are Invertebrates. 
• These are lower animals.

Chordates: 

• The major group of animals which have notochord or vertebral column are chordates. 
• These are higher animals.

(c) birds only

All Vertebrates have notochord during embryonic development. Later it is replaced by the vertebral column. But in lower chordates like prochordates, vertebral column is not present. They have only notochord in the adult or larval stage. Hence it is said that all vertebrates are chordates but all chordates do not have vertebrate characters

(d) achieve all of the above

(c) birds and insects

(b) Chordates which have notochord in the tail region of larval forms.

(b) metanephric

(b) Lampreys and hag fishes

• These fishes have bony endoskeleton. 
• The skin is covered by ganoid, cycloid or ctenoid scales. 
• Gills are covered by an operculum. 
• They are ammonotelic. 
• They have mesonephric kidneys. 
• External fertilization is seen.

Cartilaginous Fishes: 

• These have powerful jaws which help in predation.
• These are free living predatory fishes.
• These are advanced over jawless fishes. 
• These have a tough skin covered by dermal
• Respiration is by lamelliform gills without operculum. 
• Paired fins are present. 
• Fertilization is internal 
• Viviparous e.g. Scoliodon

(c) Tunicates

1. Herdmania belongs to phylum Urochordata. 

2. It is called a chordate as it shows the following features: 

a. Presence of notochord at least in early embryonic life. (In Herdmania, notochord is present in the tail of the larval forms). 

b. Presence of hollow, dorsal nerve chord, running throughout the length of the body. 

c. Presence of pharyngeal gill slits. 

d. Presence of post-anal tail.

Ventral and tabular heart. Respiration is through gill slits.

a. Moulting or eedysis is a periodic shedding of the outer cuticle layer of body in arthropods. 

b. The outer layer of body of arthropods is formed of tough, non-living chitinous substance. 

c. If arthropods do not moult, they cannot grow and mature into adult forms

Significance: 

Beneficial arthropods: Some arthropods are of economic importance. For example, Honey bees (Apis) are important for their honey and wax, silkworms for the production of silk. Lobsters, prawns, crabs are edible. 

Harmful arthropods: Some arthropods are harmful and act as vectors to spread various diseases,

e.g., Mosquitoes. Locusta (locust) is a gregarious pest. Limulus (King crab) is a living fossil.

Other examples: Cockroach (Periplaneta), butterfly, scorpion (Hottentotta) and millipede (Archispirostreptus) prawn.

(b) excretion

(c) Garden lizard

(c) Naja Hannah

(b) Trap moisture

(c) water fleas

(d) proboscis gland

(a) Keber’s organ

(c) ommatophore

Radial of the following symmetries is found in adult sea anemone.

(b) Echinodermata

Choanocytes perform nutrition.

(c) selection and rejection of food

(d) i – r, ii – s, iii – q, iv – p

(a) They have segmented legs

(a) Aves is the vertebrate group of animals characterized by crop and gizzard in its digestive system.

(c) Annelida, Arthropoda and Chordata

• Molluscs are terrestrial or aquatic with organ system level of organisation.
• They are triploblastic, bilaterally symmetrical, coelomate animals.
• Body is divided into head, foot and visceral hump.
• The digestive system is complete
• Nephridia are the excretory organs.
• Open type of circulatory system is seen.
• Blood contains copper containing respiratory pigment called hemocyanin.
• They are oviparous. 
• Development is indirect with a veliger larva, e.g., Pila and Octopus.

These are bilaterally symmetrical, triploblastic, schizocoelomate, segmented animals.

• They have organ system grade of organisation.
• They have jointed appendages
• Body is covered by chitinous exoskeleton. Body is divided into head, thorax and abdomen.
• Body cavity is filled with colourless blood. It is called haemocoel.
• Respiratory organs are gills, book gills, book lungs, trachea.
• Open type circulation is seen.
•  Sense organs are present.
• Fertilization is internal, e.g., Limulus and insects.

• They are aquatic or terrestrials, free living or parasitic.
• They are triploblastic, bilaterally symmetrical, schizocoelomates with organ system level of organisation.
• The body is metamerically segmented. 
• Longitudinal and circular muscles help in locomotion.
• Closed type of circulation is seen. 
• Respiratory pigments are present. 
• Sexual reproduction is seen. 
• Development is direct or indirect with a trochophore larva e.g., earthworm.

(b) Annelida

Correct Answer is: (a) Annelida

In some animals, body consists of many segments arranged along the length of the body. When the external segmentation coincides with the internal segmentation, it is called as metameric segmentation and the phenomenon is called metamerism.

Correct Answer is: (b) Pheretima

Body cavity lined by mesoderm is called coelom.

(b) cnidaria (coelenterate)

(c) merostomata

Tissues are absent in the body of sponge.

Metameric segmentation is the main feature of Annelida.

(c) Arthropoda

(a) Annelida