The structure of plasma membrane makes it selectively permeable allowing it to regulate the passage of substances into and out of the cell. Small nonpolar molecules can easily across the phospholipid bilayer of plasma membrane because it is hydrophobic. Polar molecules and ion cannot easily across the hydrophobic portion of plasma membrane because it is hydrophilic. Polar molecules and ions usually across the plasma membrane with the help of transport proteins.
Answer
Operons are cluster of coordinated genes, including structural genes, an operator gene, and a regulatory gene.
Explanation:
In the The repressible operons, The transcription is usually on and repressor is in inactive form, So the specific genes are transcribed. While a regulatory molecule act as corepressor and binds to repressor protein to activate it. The repressor protein cause the inactivation of repressible operon (as the name indicate). E.g., Tryptophan Repress the trp operon.
A high level of product act as regulatory molecule (Corepressor) and turn off the operon, So anabolic pathways or synthesis of essential components are controlled by repressible operon.
In the Inducible operons, the transcription is usually off and repressor is in active form. So there is no transcription of genes. Specific Metabolite cause the activation of operon e.g lactose cause the induction of lac operon.
As a metabolite induces the operon, So they control the Metabolic pathways or breakdown of a neutrient.
Threatened means they are lowering in numbers and nearing to be endangered.
Endangered means they are dangerously close to being extinct
Extinct means there is none of them left in the wild.
I hope this is what you meant.
Answer: false
because Biodiversity is the biological variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic, species, and ecosystem level. Terrestrial biodiversity is usually greater near the equator, which is the result of the warm climate and high primary productivity.
What is the difference between a cell plate formation and a cleavage furrowformation? Cell plate formation occurs during cell division in plants whereascleavage furrow form during celldivision in animal cells. Cell plate andcleavage furrow appears in the middle of cell.
