What is a fossil?
Fossils are fossilised (petrified) remains of animals/plants. A fossil though, is only a fossil, when it is from a different geological era.
How does that relate to evolution?
Evolution and fossils are very related. When we scan the DNA of different fossils, we find that the DNA can be similar to living species we have today, which helps us trace back their origins.
Tracing back a species origins is not something we do just to see how that species changed along time. When we manage to make an evolutionary chart of a species, we know how they changed, what they changed, and maybe not more, but very importantly, when the previous species were extinguished. If we know when they were extinguished, we can find out what caused that extinction:
- A lack of adaptation.
- Lack of resources.
- Temperature changes.
- Increase of predators.
- Deadly migrations.
- Other natural disasters.
So, in other words, by studying one species, we can study our own planet.
Hope it helped,
BioTeacher101
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.
Answer:
Cytology is the study of individual cells of the body.