Zoology

FATEMAP OF FERTILISED EGG OF AMPHIOXUS: Conklin in 1932 studied the fate map of Amphioxus.…
Amphioxus is a Cephalochordate animal. Its Life history in the early stages shows resemblance with…
In amphioxus a big space is present, called Atrium it is lined by ectoderm. It…
In the Urochordate and Cephalochordate animals the ventral side of the pharyhx wilI contains endostyle.…
In chordate animals notochord, dorsal tubular nerve cord and pharyngeal slits are present.   In…
Exoskeleton is absent in Branchiostama. Endoskeleton include the notochord, gelatinous rods and plates, fin-ray boxes…
Amphioxus belongs to Cephalochordate. In 1778 Amphioxus was first discovered and described by Palias. He…
The sub-phylum Cephalochordata includes a single class Leptocardii, which has single family, Branchiostomidae. The family…
Cephalochordata includes two genera, 1. Asymmetron and 2. Branchiostoma (Amphioxus). Cephalochordates are small fish like…
Phylum Chordate is divided into three Sub-Phyla.   SUB-PHYLUM: UROCHORDATA SUB-PHYLUM: CEPHALOCHORDATA SUB-PHYLUM: VERTEBRATA  …
CHORDATES   The Phylum Chordate includes bilaterally symmetrical, metamerically segmented, triploblastic, enterocoelomate metazoans exhibiting hights…
The animal kingdom is divided into two sub-kingdoms:   Chordata Non-Chordata   GENERAL CHARACTRS OF…
THEORIES ABOUT ORIGIN OF CHORDATES   It is believed that Chordates have originated from invertebrates.…
In Eutherian mammals the embryo develops in the uterus of mother. The developing embryo will…
There is an interrelation between the form of teeth arid nature of food. These may…
The tooth develops partly from the epidermis and partly from the mesenchyme of dermis. Its…
Two main theories have been proposed to explain the evolution of molars.   CONCRESCENCE THEORY…