Which happened during the paleozoic era?

a. sponges and invertebrates dominated the seas.

b. bony fish evolved.

c. no life was present yet on earth.

d. bacteria were the dominant life-forms.

All ova contain sex chromosomes corresponding to: x y xx xy

5. what might happen if you were to remove all light from the setup after the discs have all become buoyant? describe what you would see. explain why this would occur with relation to cellular processes like respiration. [referring to an ap biology lab in which spinach discs are placed in a sodium bicarbonate solution and exposed to light.]

Transposon can cause mutations in genes at or near the site of transposon insertion. it is possible for these elements to transpose away from their original site, causing a reversion of the mutant phenotype. in some cases, however, even more severe phenotypes appear when these elements excise from this site, due to events at or near the mutant allele. what might be happening to the transposon or the nearby gene to create more severe mutations?