In which class would you place any organism which has

(i) a scaly exoskeleton and a bony endoskeleton

(ii) a scaly exoskeleton and lay eggs outside water?

What is symbiosis? Name a symbiotic life form. Mention specific organisms which display the symbiotic relationship in this life form.

| Identify two features possessed by all chordates.

List three groups of plants. Which plants are referred to as vascular plants? Out of these which group is further classified on the basis of number of cotyledon? State its two characteristics.

List in the tabular form any three differences between the Aves and Mammalia group.