Answer:
Please find the detailed explanation of this statement below
Explanation:
Firstly, a repressed gene is a gene whose expression has been inhibited or repressed. The lac operon in E.coli bacteria is a regulatory unit containing structural genes, a single promoter and operator regions. The promoter is the region where the transcription enzyme (RNA polymerase) binds to in order to transcribe the genes in the lac operon. The structural genes in the lac operon can only be expressed in the presence of lactose sugar.
However, in the absence of lactose, LAC REPRESSOR, which is a transcription factor (protein), prevents the binding of RNA polymerase to the PROMOTER region by binding to the OPERATOR region of the lac operon. This inhibits the expression of the lactose genes in the operon.
Note that, the structural genes in the lac operon (lacZ, lacY, lacA) code for proteins that help break down lactose sugar for energy in the E.coli bacteria. Therefore, a bacteria cell with a repressed lac operon will be unable to degrade lactose sugar.
Some stimuli act as attention-getting stimuli due to their physical characteristics; others, due to their meaningfulness, act as attention-holding stimuli.
For example, somebody's physical appearance, of a person who is attractive, is used as an attention-getting stimuli, but their psychological qualities are what hold your attention due to their meaningfulness.
The answer fo this i think it’s OX
Answer:
A pteridophyte is a vascular plant that disperses spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden. Ferns, horsetails, and lycophytes are all pteridophytes.
Explanation:
Answer:
False
Explanation:
The most specific feature of cardiac muscles is the presence of intercalated discs. Intercalated disc connects the ends of cardiac muscle fibers to one another. The discs have desmosomes and gap junctions. The function of desmosomes is to hold the cardiac fibers together. The gap junctions of cardiac fibers allow muscle action potentials to spread from one cardiac muscle fiber to another. These gap junctions have tubular connexons that form channels and connect the cytosol of adjacent cardiocytes to allow the flow of ions and spread of action potential from one cell to another.
