1471. Invertebrates were the firs animal to evolve . Fossil evidence of invertebrates dates back to the late Precambrian _________ years ago.

A. 300 Million
B. 400 Million
C. 500 Million
D. 600 Million *

1472. Which of the followings are invertebrate animals ?

A. Sponges ,Cnidarians and flatworms
B. Mollusca, arthropods and insects
C. Segmented worms and echinoderms
D. All of these *

1473. The key characteristics of invertebrates are following :

A. No backbone
B. Earliest animals were invertebrates
C. Ectothermic
D. All of these *

1474. How many percent of all living species are invertebrates in world ?

A. More than 67 percent
B. More than 77 percent
C. More than 87 percent
D. More than 99 percent *

1475. The earliest known fishes were the ostracoderms, a now-extinct group of jawless fishes , that appeared in the Cambrian period , about _________ years ago.

A. 310 Million
B. 410 Million
C. 510 Million *
D. 710 Million

1476. The key characteristics of fishes are following:

A. Vertebrates
B. First animals to evolve jaws
C. Breathe using gills
D. All of these *

1477. Which were the first vertebrates to make the move from life in water to life on land ?

A. Mammals
B. Reptiles
C. Amphibians *
D. None of these

1478. Aschelminathes is known as :

A. Protozoans
B. Eumatazoa
C. Nematodes *
D. None of them

1479. A hydrostatic organ found in most bony fishes that can change the gravity of fish by filling with gas so the fish can float high or sink lower in water is :

A. Swim Bladder *
B. Fins
C. Steam
D. Tail

1480. Which of the following one is not included in protostomes ?

A. Arthropods
B. Hemichordates *
C. Annelids
D. None of them