Polarity- Epithelium is arranged so there is one free surface (apical surface) and one attached surface (basal surface)
Cellular nature– Cells in epithelium fit closely together side by side and sometimes atop each other to form sheets of cells.
Answers:
A(n) operon is a stretch of DNA consisting of an operator, a promoter, and genes for a related set of proteins, usually making up an entire metabolic pathway.
The Gene of an operon is arranged sequentially after the promoter
A(n) promoter is a specific nucleotide sequence in DNA that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place.
A(n) regulatory gene codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.
Regulatory proteins bind to the operator to control expression of the operon.
A(n) repressor is a protein that inhibits gene transcription. In prokaryotes, this protein binds to the DNA in or near the promoter.
A(n) inducer is a specific small molecule that binds to a bacterial regulatory protein and changes its shape so that it cannot bind to an operator, thus switching an operon on.
when their is a disaster of some sort reduces a population to a small handful.
Answer: Option D.
Explanation:
Insufflation is a method which is used as a route of administration for drugs through nasal cavity.
The nasal cavity is having a thin vascularised mucosal layer, therefore during Insufflation when a drug molecule is administered, it transferred quickly across the layers of epithelial cell directly into lymphatic system and starts it"s effect within 5 minutes.
Hence, Insufflation is a method which is used to absorb drugs through mucosal membrane.