Answer:
C. a decrease in the chromosome number in every generation.
Explanation:
hope it helps .
Answer:
silica
Explanation:
Diatoms are microscopic organisms. they have shell that is made from organic compounds and silica.Diatoms contain silica in their cell walls. This material is used industrially in the production of toothpastes, silver polishes, and swimming pool filters. Silica is used to remove stains and debris.
Answer:
I believe the answer is B
Explanation:
Don't quote me
Answer:
D) Adenine, Guanine, Cytosine, and Uracil
Explanation:
RNA shares three of the nitrogenous bases of DNA: Adenine, Guanine, and Cytosine. However, instead of thymine, it has Uracil!
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.
