Answer: With the development of powerful microscopes, scientists discovered many single-celled organisms that didn't fit into any of Linnaeus' kingdoms. As a result, a new taxon, called the domain, was added to the classification system.
Explanation:
Answer:
The answer is B. Stratum Basale
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.
Hypertonic solution means the solution with a lower water potential than the cell cytoplasm, such as salt water.
When the red blood cell is put into it, since the cell has a higher water potential than the solution, water molecules will flow from the cell back into the water due to osmosis.
Osmosis is always where water molecules flow from a region of higher water potential to lower, through a semi permeable membrane (Whcih is the red blood cell membrane in this case.)
Since water flowed out of the cell, the cell lose water and shrinks.
Hypotonic solution is where the solution that has a higher water potential than the cell cytoplasm.
So when the red blood cell is put in that solution, the water will flow from the solution into the cell this time, by osmosis.
The red blood cell will then gain so much water that the cell membrane cannot hold all and therefore burst.
