Answer:
A gene is a section of a double-stranded molecule known as DNA. This molecule is found within the nucleus of the cell, contained in threadlike structures called chromatin. The two strands form a double helix linked by a series of paired bases. The base adenine is always linked to thymine and the base cytosine is always linked to guanine.
<span>Wave erosion of headlands formed the Province Spit in Cape Cod</span>
<span>The random changes a mutation causes to an organisms genetic code causes either
1. A different protein to be produced or
2. none at all
Mutations can either have a positive, negative or neutral (the vast majority) effect on the organism. (many times whether they are harmful or helpful depends on the environment.)
When a mutation makes an organism better able to survive that organism is more likely to survive and pass the mutated gene onto the next generation.</span>
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:
Explanation:
I would like to photograph a tulip, because I have always been interested to know more about some flowers and what’s in the inside of them. Even though tulips look pretty “simple” but beautiful in the outside, I suspect that there are a thousand of different things inside of it.
