Answer:
False
Explanation:
The histones that are more positively charged, tight hardly to negatively charged DNA. So, enzymes, such as acetyltransferases, that reduce the positive charge of histones promote transcription.
Chromatin structure and its modifications can change the package of the DNA and consequently, alter the gene expression. The most common modifications of the chromatin are covalent modifications such as acetylation/deacetylation (by acetyltransferases and eacetylases), methylation (by methyltransferases), and phosphorylation (by kinases). This is the way of gene expression regulation.
The effects of modifications are different, for example methylation promotes condensation of the chromatin and as a consequence, prevents binding of transcription factors to the DNA (transcription is repressed).
Acetylation loosens the association between nucleosomes and DNA (because it neutralizes the positive charge of histones) and consequently promotes transcription. Deacetylation is a process opposite to acetylation.
Answer:
ok
Explanation:
Simple sentences contains on independent clauses ,also called main clause ,that stands alone.
Complex sentences contains an independent clauses plus one or more dependent clause.
Compound Sentences contains two independent clauses joined with the coordinating conjugation and comma .AND IT'S ENGLISH QUESTION NOT OF BIOLOGY.
Answer:
When the frequency of stimulation of a muscle increases -without it having the opportunity to relax- a process called summation (addition) occurs, promoting an increase in the generation of force in the isolated skeletal muscle.
Explanation:
Summation is a phenomenon that occurs as a consequence of the arrival of successive stimuli that produce the contraction of the skeletal muscle before it achieves its partial or total relaxation, between subsequent stimuli.
<em>When the summation occurs in the muscle, the force generated on it increases its magnitude proportionally to the number of stimuli received, maintaining the muscle contraction in time</em>.
Tetany is the prolonged contraction of a muscle in an abnormal way, by the summation of stimuli received , as some bacterial toxins can produce. The summation can be temporary -when multiple stimuli reach the muscle in a determined time- or spatial, when the amount of stimuli activates a greater amount of motor units.
Learn more:
Spatial summation in a post synaptic neuron brainly.com/question/9632682
The answer to your question is <span>chemical energy
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