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 most serious type of accident which could occur at a nuclear power plant is <span>core meltdown caused by a failure of water to circulate among the fuel rods.
This is what happened in F.ukushima, Japan, in 2011, after a series of devastating earthquakes and tsunamis. This is why F.ukushima is still experiencing extremely high levels of radiation and parts of that area cannot be inhabited anymore.
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Answer:
Human activities affect the flow of energy and matter in an ecosystem and alter the energy balance in ecosystems through the unsustainable nature of what they do. The energy flow is affected in several ways as a result of pollution, overpopulation, deforestation, burning fossil fuels, etc. Such changes have stimulated soil erosion, climate change, causing water unfit to consume, poor quality of air and so on. When humans cause a change in the energy balance, they impact the ability of the ecosystem to respond and adapt to changes in the environment. It is like getting a cut, but it never heals and grows bigger instead.
Answer is <span>c. penicillin </span>
Answer:
Photosynthesis converts carbon dioxide and water into oxygen and glucose.
Explanation:
Glucose is used as food by the plant and oxygen is a by-product. Cellular respiration converts oxygen and glucose into water and carbon dioxide. Water and carbon dioxide are by- products and ATP is energy that is transformed from the process.
