The answer is true.
A placer deposit is a deposit of earth, sand, or gravel formed due to the differential settling of the denser, heavier components. The placer contains particles of valuable mineral and it is found usually in the bed of a river or lake.
When the continents are at the Earths poles, they receive less sunlight.
Answer:
D) presence of transcription activators or repressors
Explanation:
The reason why this is not post-transcriptional regulation is that activators actually start the process of transcription by binding to specific sites. while on contrary when repressor binds it halt the process.
For example, there is a protein called CAP which in the presence of cAMP bind with promoter region and enhances the activity of RNA polymerase . While in the absence of cAMP it can not bind to promoter hence the transcription stooped.
A hormone is a molecule that functions as a chemical signal. A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Endocrine hormone molecules are secreted (released) directly into the bloodstream. !