Answer:
A) A corepressor must be present
Explanation:
The key to operon expression lies in the sequence of the operator and the presence or absence of a repressor. When the repressor binds the operator, it prevents RNA polymerase from initiating transcription. The capability of the repressor to bind the operator and inhibit transcription depends on the conformation of the repressor, which is regulated allosterically by a key compound in the metabolic pathway, such as lactose or tryptophan. In a repressible operon, such as the tryptophan (or trp) operon, the repressor is unable to bind to the operator DNA by itself. Instead, the repressor is active as a DNA-binding protein only when complexed with a specific factor, such as tryptophan , which functions as a corepressor.
When tryptophan is plentiful, tryptophan molecules act as corepressors by binding to the (1) inactive repressor and (2) change its shape, allowing it to bind to the operator, (3) preventing transcription of the structural genes
Answer:
Cystic fibrosis is an inherited disease caused by mutations (changes) in a gene on chromosome 7, one of the 23 pairs of chromosomes that children inherit from their parents. CF occurs because of mutations in the gene that makes a protein called CFTR (cystic fibrosis transmembrane regulator).
Explanation:
Answer:
The correct answer is - The decomposers decompose dead algae and plants which take up most of the oxygen.
Explanation:
Eutrophication is taken place when there is a high amount of nutrients, minerals are present in a waterbody which allow algae to grow rapidly and cause depletion of oxygen due to the decomposition of dead organisms. There are the following stages in the eutrophication process:
- rapid growth of Algae and other plants
- due to algal bloom, the sunlight is blocked, and plants and organism start dying.
- The decomposers take up most of the oxygen by decomposition
- The animals start dying without oxygen
In the case of liquid droplets, including water, surface tension is the factor, which is accountable for their shapes and configuration. Though can easily be malformed, the droplets of water seem to be pulled into a spherical shape due to the cohesive forces of the surface layer.
In the non-existence of other forces, involving gravity, the drops of almost all the liquids would be almost spherical.
Hello,I think that the answer is C. It is a salt, because it is formed by the reaction of an acid and a base.Hope I Helped.