A spiral galaxy is a galaxy where the stars and gas clouds are concentrated mainly in one or more spiral arms. Most spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a concentration of stars known as "the bulge". The disk of stars orbiting the bulge separates into arms that circle the galaxy. These spiral arms contain gas and dust and younger stars that shine brightly before they dull. Most of the galaxies that scientists have discovered so far are spiral galaxies. One example of a galaxy in our solar system is The Milky Way. Spiral galaxies make up roughly 72 percent of the galaxies that scientists have observed. How the spiral arms form continues to puzzle scientists. One theory suggests the galaxy arms could be the result of density waves traveling through the outer disk. Galaxies at a whole are quite a fascination.
Answer:
a bicyclist travels 60.0 kilometers in 3.5 hours what is the bicyclist average speed?
Average speed= 4.76m/s
Explanation:
Speed= distance/time
distance= 60km= 60 X 1000= 60,000m
time= 3.5 hours= 60 X 3.5= 210 minutes= 210 X 60= 12600 seconds
Therefore speed= 60000m/12600s
Speed= 4.76m/s
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:
The correct option is trial and error learned behavior
Explanation:
A trial and error learned behavior is a type of behavior in which an organism attempts to or tries something new which makes it (the organism) accept the reality of that thing or situation. This means that if the attempt is successful or pleasurable, the organism will attempt it again and if it's not, the organism will avoid that thing.
This is what was described in the question with the bird trying to eat the caterpillar but found it unpleasurable which made it to start avoiding it afterwards.
Answer:
B. atrioventricular (AV) valve
Explanation:
The function of the conduction system of the heart is to spread the electric signal and make the heart contract in coordinated timing. Conduction starts at SA node, then the AV node then will spread by bundle branches.
The atrioventricular valve is not part of the conduction system. The valve function is to keep the blood flow back. If the valve is broken and blood did flow back, it can make the heart need to do more work than usual.