Answer:
What sends oxygenated blood back to the heart from the lungs?
Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.
Explanation:
Answer:
The correct answer is option (D) there was a time in Pennsylvania history when dinosaur existed.
Explanation: A paleontologist discovers a rock slab on which the footprints of a Pennsylvania dinosaur are well preserved. This means that there was a time in Pennsylvania history when dinosaur existed in this area. Here fossil is a fragment of rock on which the footprints of dinosaur is present.
Answer:
A) A transgene integrated into a heterochromatic region of the genome.
Explanation:
This is most likely the reason why the transgene is not expressed in the fifth cell line. It is likely that the transgene was integrated into a heterochromatic region of the genome. Heterochromatin consists of genetically inactive satellite sequences, and many of these are repressed to various extents. Moreover, because this is a tightly packed form of DNA or condensed DNA, it is inaccesible to polymerases and thus not transcribed.
Answer:
ATP contains energy in the chemical bonds between its phosphate groups, best explains how the structure of ATP helps provide energy to the cell.
Explanation:
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