Which one of the followings in birds, indicates their reptilian ancestry?
Scales on their hind limbs
Four chambered heart
Two special chambers crop and gizzard in their digestive tract
C.
Two special chambers crop and gizzard in their digestive tract
Nearly a century ago, T H Huxley called birds 'glorified reptiles' thereby meaning that birds have evolved from some reptilian ancestor. Both birds and reptiles lay the same type of eggs, which are deposited outside water. Eggs are large and telolecithal. The ovum is surrounded by albumen, an egg membrane and a thick hard calcareous shell, which are all secreted by special glands located in the walls of the oviduct.
Birds like mammals have a completely four-chambered heart with double circulation, in which there is no mixing of pure and impure blood., All birds have horny epidermal scales confined to the lower parts of their legs and feet, which are exactly like the epidermal scales of the reptiles. Besides birds are covered by feathers, which are homologous to the reptilian horny scales as they have a similar origin and develop from similar germ buds.
Crocodile and penguin are similar to whale and dogfish in which one of the following features?
possess a solid single -stranded central nervous system
lay eggs and guard them till they hatch
possess a bony skeleton
possess a bony skeleton
Which one onf the following groups of animals is bilaterally symmetrical and triploblastic?
Coelenterates (cnidarians)
Aschelminthes (roundworms)
ctenophores
ctenophores
Which one of the following statements about certainly given animals is correct?
Roundworms (Aschelminthes) are pseudocoelomates
Molluscs are acoelomates
insects are pseudocoelomates
insects are pseudocoelomates
Cellulose is the major component of cell walls of
Pythium
Xanthomonas
Pseudomonas
Pseudomonas
Which one of the following pairs of animal comprises' jawless fishes'
Lampreys and eels
Mackerels and rohu
Lampreys and hag fishes
Lampreys and hag fishes
Which one of the following statements about all the four of Spongilla, leech, dolphin and penguin is correct?
Penguin is homoiothermic while the remaining three are poikilothermic
Leech is a fresh water from while all other are marine
Spongilla has special collared cells called choanocytes, not found in the remaining three
Spongilla has special collared cells called choanocytes, not found in the remaining three
A change in the amount of yolk and its distribution in the egg will effect
formation of a zygote
the pattern of cleavage
number of blastomeres produced
number of blastomeres produced
Which one of the following is not a characteristic of phylum-Annelida?
Closed circulatory system
Segmentation
Pseudocoelom
Pseudocoelom
Which one of the following kinds of animals are tribalistic?
Flatworms
Sponges
Ctenophores
Ctenophores
