Which one of the following in birds, indicates, their reptilian ancestry?
Scales on their hindlimbs
Four-chambered heart
Two special chambers crop and gizzard in their digestive tract
Eggs with a calcareous shell
C.
Two special chambers crop and gizzard in their digestive tract
Nearly a century ago TH 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 gland located int he walls of oviduct.
Birds like mammals have completely four chambered heart with double circulation, in which there is no mixing of pure and impure bloods. Whereas the ventricle is imperfectly divided in reptiles, resulting in partial mixing of bloods.
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.
Select incorrect pair
Porifera – Choanocytes
Coelenterata – Nematocysts
Annelida – Segmentation
Monera – Eukaryote
Bilateral symmetry, metameric segmentation, coelom and open circulatory system are the features of
Annelida
Arthropoda
Mollusca
Echinodermata
Which type of white blood cells are concerned with the release of histamine and the natural anticoagulant heparin?
Neutrophils
Basophils
Eosinophils
Monocytes
If a child is of O blood group and his father is of B blood group, the genotype of father is
IO IO
IA IB
IO IB
IO IA
Correctly matched set of phylum, class and example is
Protozoa-Mastigophora-Entamoeba
Mollusca=-Bivalvia-c-Pmcrcdc
Arthropoda-Diplopoda-Scolopendra
Chordata-Cyclostomata-Phrynosoma
