Answer:
Because of how genes change and how quickly they change, evolution is complicated. At the start of evolution, there shouldn't be a straight tree branch—it should be a twisted mess.
Answer:
Jaws and a swimming bladder
Explanation:
A defining characteristic between sharks and rays that distinguish them from ray-finned fish is the *possession of jaws in sharks* and rays;and the *possession of swimming bladder in ray-finned fishes*.
Characteristics of sharks and rays are as follows :
They are cartiiliginous fishes; they possess *strong jaws* lined with teeth; body dorsoventrally flattened, fusiform (spindle shaped) with heterocercal tail(diphycercal in Chimaeras); paired fins; *no swimming bladder or lungs*; pelvic fins in males often modified to form clappers; Gill arches internal to gills; reduced notchord; lateral-line system; paired nostrils; internal nares absent; separate sexes; internal fertilization and direct development; oviparous, oviparous, or ovoviviparous. Examples include, Spiny dog fish or dog shark, Ray Raja, Chimaera.
Characteristics of ray-finned fishses:
They generally lack paired fins; no internal nares; *air sacks usually function as swimming bladder*; skeleton usually well ossified. Blind olfactory sacs (do not open into the mouth); Tail homocercal. Examples include Tilapia, Claris,and Polypterus.
State the problem
Research
State the hypothesis
Test the hypothesis
Analyze the results
Conclusion
The main function of DNA polymerase is to synthesize DNA from deoxyribonucleotides, the building blocks of DNA.
