Search results
Results from the WOW.Com Content Network
Frogs have a highly developed nervous system that consists of a brain, spinal cord and nerves. Many parts of frog brains correspond with those of humans. It consists of two olfactory lobes, two cerebral hemispheres, a pineal body, two optic lobes, a cerebellum and a medulla oblongata.
Dissection of a frog. Pain is an aversive sensation and feeling associated with actual, or potential, tissue damage. [1] It is widely accepted by a broad spectrum of scientists and philosophers that non-human animals can perceive pain, including pain in amphibians.
The axon hillock is a specialized domain of the neuronal cell body from which the axon originates. A high amount of protein synthesis occurs in this region, as it contains many Nissl granules (which are ribosomes wrapped in RER) and polyribosomes. Within the axon hillock, materials are sorted as either items that will enter the axon (like the ...
Chicken embryos have 50 somites; mice have 65, while snakes have 500. [4] [8] As cells within the paraxial mesoderm begin to come together, they are termed somitomeres, indicating a lack of complete separation between segments. The outer cells undergo a mesenchymal–epithelial transition to form an epithelium around each somite.
Each is a member of one of three monophylitic clades. All tunicate larvae have the standard chordate features, including long, tadpole-like tails. Their larva also have rudimentary brains, light sensors and tilt sensors. [28] The smallest of the three groups of tunicates is the Appendicularia. They retain tadpole-like shapes and active swimming ...
"Fewer than a dozen of the 6455 species of frogs in the world are known to have internal fertilization, and of these, all but the new species either deposit fertilized eggs or give birth to froglets."
Kermit the Frog meet Kermitops gratus, the most recent ancient amphibian to be identified after examination of a tiny fossilized skull that once sat unstudied in the Smithsonian fossil collection ...
Metazoans do not include the sponges, which have undifferentiated cells. [16] Unlike plant cells, animal cells have neither a cell wall nor chloroplasts. Vacuoles, when present, are more in number and much smaller than those in the plant cell. The body tissues are composed of numerous types of cells, including those found in muscles, nerves and ...