The lac operon, which stands for Lactose operon is known as an inducible system. It is the an operon required for the transport and metabolism of lactose some enteric bacteria (Echerichia coli for example). The Lac operon is only activated in the presence of a key molecule. The key molecule is lactose.
From the given options the following best describes the Lac operon:
D. The repressor is freed from the operator when lactose is present.
Answer:
Abstract
Respiratory homeostasis is concerned with the regulation of a blood gas composition that is compatible with maintaining cellular homeostasis. Provided that the lung-capillary exchange barrier does not prevent the exchange of gases, then blood leaving the lung will have oxygen and carbon dioxide partial pressures that are similar to the average values found in the alveoli. Alveolar ventilation establishes these values. If blood gas composition, especially of carbon dioxide, moves outside the homeostatic range, the change is detected by chemoreceptors and respiratory responses are promoted which change alveolar ventilation, alter alveolar gas composition and so reverse the change. Ventilation therapies provide the means of artificially restoring alveolar gas composition. In general terms, they do this by raising the partial pressure of oxygen within the alveoli either by using oxygen-enriched gas mixtures, or by improving the ventilation of alveoli using positive pressure.
Explanation:
Step 1: Copy of one side of DNA strand is made (called mRNA, messenger RNA)
step 2: mRNA moves to cytoplasm, then ribosome
step 3: mRNA goes through ribosome 3 bases at a time
step 4: transfer RNA (tRNA) matches up with the open DNA bases
step 5: tRNA releases the amino acid at the top, which joins the chain of amino acids being produced
Explanation:
Velocity refers to how fast the air is moving in distance per unit of time. While pressure is the measure of force applied on an area.
