Plants obtain water from air as well as rain, carbon dioxide from the atmosphere and expelled human breath, energy from the sun.
Answer:
1. Histone methylation occurs at different amino acids: c. Activates and inactivates
2. A transcriptional binds an enhancer sequence: d. No effect
3. Histone acetyltransferase attach acetyl groups to the N-terminus of histones: a. Activates
4. Histone deacetylases remove acetyl groups from the N-terminus of histones: b. Inactivates
Explanation:
Epigenetics refers to the mechanisms associated with changes in gene expression which do no involve alteration in DNA sequence. Epigenetic marks include DNA methylation and histone modifications (acetylation, methylation, phosphorylation, etc). These mechanisms act together in order to regulate gene expression at specific genomic sites (<em>loci</em>). Histone methylation is an epigenetic mark involved both in transcriptional repression and transcriptional activation. For example, trimethylation of the histone H3 at lysine 4 (H3K4me3) has been associated with transcriptional activation, while dimethylation of histone H3 at lysine 9 (H3K9me2) is often involved in transcriptional repression. Moreover, histone acetylation by histone acetyltransferases (HATs) is an epigenetic mark that is involved in transcriptional activation and chromatin decondensation, while histone deacetylation by deacetylases (HDACs ) is generally associated with gene repression. However, it is important to highlight that there are exceptions to this rule (for example, acetylation of the histone H4 lysine 20 is associated with gene repression). Finally, transcriptional activators are proteins that bind to enhancers in order to recruit coactivator proteins/complexes and thus activate transcription.
Answer:
Television broadcasting
The transmission of visual images of moving an stationary objects, generally with accompanying sound, in the form of electromagnetic waves that when received can be reconverted into visual images.
Very high frequency (VHF)
A band of radio frequencies falling between 30 and 300 MHz; VHF signals are widely employed for television and radio transmissions. In the United States and Canada, television stations that broadcast on channels 2 through 13 use VHF frequencies, as do FM radio stations. Many amateur radio operators also transmit on frequencies within the VHF band.
politics tbfh but this answer has to be 20 characters sooooooooooooo
