In mammals, the action of modifying gene expression in which one X chromosome is inactivated in the cell of females differs from how miRNA performs gene silencing in that

miRNA blocks transcription factors.
miRNA is a method of posttranscriptional gene silencing.
miRNA modifies histones on DNA.
miRNA methylates acetyl groups to repress translation.

Aplant has an egg with 34 chromosomes how many chromosomes does a leaf cell of that plant have

Radiometric dating is used to tell the absolute age of materials by studying the decay rate of radioactive isotopes. the decay rates of isotopes are constant and are expressed as .

1. seamount a raised footwall block between normal fault creates this 2. syncline break between rocks where a hanging wall rises relative to a footwall 3. hot spring on rolling hills, this a dip between hills 4. volcanic neck created when a block with hanging walls slips down between normal faults 5. caldera underwater volcano that never reaches above sea level 6. horst natural hot water on earth's surface containing many minerals 7. graben underwater volcano whose top is eroded flat by waves 8. crater less than a mile in diameter; looks like a bowl at the top of a volcano 9. guyot magma that filled the central vent that remains after the volcano has eroded 10. reverse fault over 1 mile in diameter; looks like a bowl over a volcano