Answer:
At the base of Actinopterygii
*This is a unique characteristic of this group.
Explanation:
A peculiar characteristic organ observed in ray-finned fish (as well as in Sarcopterygii, or lobe-finned fish) but not in cartilaginous fish like shark is the swim bladder.
This organ is often described to be a sac containing gas. It helps these set of fish adjust its buoyancy and its position in the water by regulating the concentration of gas present in it.
The swim bladder is formed as a pouch coming off the embryonic digestive tract, and in chondrosteans and holosteans, with a set of teleosts e.g. the eels, it maintains an open pathway to the esophagus. In majority of the bony fish, the swim bladder is totally sealed off, as gas levels in their swim bladder are regulated by producing gas into the bladder via a network of capillaries, the rete mirabile (Latin word for "marvelous net").
The swim bladder is homologous to the lungs of tetrapods. Since they are formed in the same vein. Few fishes that have an open swim bladder employs it as a breathing organ.
The answer is D its the right answer because on the moon there is not oxygen for it to reach that state
Answer:
Yes, Mass Extinctions May Have Been Caused By Meteors, as the probability of mass extinction occurring after an asteroid that could hit a random location on the Earth's surface was approximately 13% when the Chicxulub-scale asteroid hit the Earth.
Soot could be the main cause of mass extinction after an asteroid impact.
Answer:
D. A silent variant near the 5' end of the TBX1 gene.
Explanation:
TBX1 gene is wild type human being. It gives instructions for making protein called T-box 1. It plays an important role in tissue formation and organs during embryonic development.
