The structure of the skin is an effective barrier against bacteria. The multiple layers of epidermis, while can be invaded by foreign organisms, has a high turnover rate which means it is constantly shedding, therefore even the bacteria is shed protecting the body. Lastly, the skin's lipids maintain an acidic pH which slows and stops growth and replication of bacteria.
Answer:
Jacob and Monod were intellectually primed to draw the conclusions they did concerning regulation of the lac operon. In part, this was due to their fascination with mechanisms of enzyme regulation. They knew that the activity of some enzymes is regulated when their reaction product binds to the enzyme, changing its shape and therefore its activity. This knowledge allowed them to easily make the intellectual leap to propose B) allosteric regulation of the repressor
Explanation:
When we talk about the mechanisms of enzyme regulation, we refer to allosteric regulation of the repressor. The Allosteric control of transcriptional regulatory proteins allows organisms to react to changes in environmental and metabolic conditions. Also, it is s a thermodynamic phenomenon. When it binds one molecule, the affinity with which a protein binds to a second molecule is altered.
In eukaryotic cells the DNA can be found in the nucleus mainly. so DNA replication takes place in the nucleus during the S phase of the cell cycle.
Also in eukaryotic cells there are mitochondria and chloroplasts (plants) and these have circular DNA and they also get replicated (according to their own mechanism).
Prokaryotic cells don't contain a nucleus. They do not contain DNA in the cytoplasm and thus the DNA replication will take place here.
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Answer:
When a new and aggressive species is introduced into an ecosystem, it may not have any natural predators or controls. It can breed and spread quickly, taking over an area. Invasive species can change the food web in an ecosystem by destroying or replacing native food sources.
Explanation:
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