Answer: Spinal cord.
Explanation:
The spinal cord of the central nervous system helps to move off quickly as a part of the reflex response. Jill stepped on a tack and suddenly he realizes that he should quickly move his legs out of the tack.
The pain is not stimulated until the signals reaches from the receptor to the brain. The formation of the reflex arc ensures that the amount of potential tissue damaged is less.
It forces the body to move quickly from the place that is causing damage.Example: Moving the leg up involuntarily when stepped on pin.
This occurs because the sensory neurons connects to the motor neurons within the spinal cord.This leads to the contraction of bones and muscles.
Hence, the correct option is spinal cord.
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.
The answer is 800 meters.
You find this by taking the total distance of the first lap and doubling it. You could also find it by adding 400 meters to 400 meters, which would total at 800 meters
The answer is <span>c. mutualism.
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<span>Mutualism is a relationship between two
different species in which both species have benefits. In this example, ants benefit because they feed on aphids' wastes while aphids benefit because ants provide them protection.
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<span>Commensalism is a relationship between two
species in which only one of them has benefit, and the other one is not
affected. Parasitism is a relationship between two species in which only
one of them has benefit, and the other one is harmed.</span><span>
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