Answer:
Since high ethanol is a major stress during ethanol fermentation, ethanol-tolerant yeast strains are highly desirable for ethanol production on an industrial scale. A technology called global transcriptional machinery engineering (gTME), which exploits a mutant SPT15 library that encodes the TATA-binding protein of Saccharomyces cerevisiae (Alper et al., 2006; Science 314: 1565-1568), appears to be a powerful tool. to create ethanol tolerant strains. However, the ability of the strains created to tolerate high ethanol content in rich media remains to be demonstrated. In this study, a similar strategy was used to obtain five strains with higher ethanol tolerance (ETS1-5) of S. cerevisiae. When comparing the global transcriptional profiles of two selected strains ETS2 and ETS3 with that of the control, 42 genes that were commonly regulated with a double change were identified. Of the 34 deletion mutants available in an inactivated gene library, 18 were sensitive to ethanol, suggesting that these genes were closely associated with tolerance to ethanol.
Explanation:
Eight of them were novel and most were functionally unknown. To establish a basis for future industrial applications, the iETS2 and iETS3 strains were created by integrating the SPT15 mutant alleles of ETS2 and ETS3 into the chromosomes, which also exhibited increased tolerance to ethanol and survival after ethanol shock in a rich medium. Fermentation with 20% glucose for 24 h in a bioreactor revealed that iETS2 and iETS3 grew better and produced approximately 25% more ethanol than a control strain. The performance and productivity of ethanol also improved substantially: 0.31 g / g and 2.6 g / L / h, respectively, for the control and 0.39 g / g and 3.2 g / L / h, respectively, for iETS2 and iETS3.
Therefore, our study demonstrates the utility of gTME in generating strains with increased tolerance to ethanol that resulted in increased ethanol production. Strains with increased tolerance to other stresses such as heat, fermentation inhibitors, osmotic pressure, etc., can be further created using gTME.
Out of the choices given, the mechanisms that drives evolution is natural selection. The correct answer is B, natural selection.
Bauxite ore is one of the primary source of aluminum but it must first be chemically processed to produce alumina (aluminum oxide). The next step of aluminum production is smelting of alumina using an electrolysis process (Hall-Heroult process). This electrolysis process is driven by electrical current. Electrolyte (molten salt) with immersed carbon anodes is used in order to dissolve the alumina. Carbon anodes are carrying electrical current and thee chemical bond between aluminum and oxygen in the alumina is broken.
Hello. This question is incomplete. Also, you forgot to show the flowchart. The flowchart is attached below and the full question is:
The flowchart below shows the three generations of a cross between a pea plant that has yellow pods and a pea plant that has green pods. Green pods are the dominant trait. The flowchart is missing the labels that describe the traits.
In which squares should the phrase “Green pods” appear?
1.A and D 2.B and E 3.A,C and D 4.A,B,C,D and E
Answer:
3.A,C and D
Explanation:
As shown in the question above, the flowchart shows the crossing of a pea plant with dominant features (green pods - AA) and a pea plant with recessive features (yellow features - aa). The crossing between plants with AA and aa alleles generates a completely Aa population, which in this case, has the dominant characteristic, that is, it has green pods. This is because the "Aa" alleles are called heterozygous and develop the dominant characteristic.
As we can see in the flowchart, the crossing between the two pea plants generated an offspring that is identified by table C, as we know this offspring has green pods and in the flowchart it is represented by a grayish rectangle. Therefore, we can say that the other gray rectangles represent pea plants with green pods, which are rectangles A, C and D.
