<span>Answer:
Think of DNA-there are only 4 bases, but different combinations give infinite possibilities.
And the same for amino acids and proteins.
Immunoglobulins work on a similar principle. Different VDJ segments are combined for the heavy chain of an antibody. Different VJ segments are combined for the light chain.
Other ways:
Random nucleotides may be added or removed between the gene segments.
There are also different combinations of light and heavy chains.
Antibodies can be any of the 5 isotypes: IgA, IgM, IgG, IgE, IgD.
I'm not going to go into detail as this answer would take too long to write. Do some literature searching on B cells, V(D)J recombination, RAG genes, class switching.</span>
Answer:
Retina; Cochlea
Explanation:
The retina is to the eye as the cochlea is to the ear.
The retina is a thin light sensitive tissue of the eyes, it lines the inside the back of the eyes. The retina receives light focused by the light and converts the light into neural impulses, and this impulses are further sent to the brain for visual recognition or perception.
The cochlea is a watery fluid found in the inner part of the ear and functions majorly for hearing. The cochlea transfers pressure waves into nerve impulses. The watery fluid moves in response to external vibration from the middle ear, this further convert motion to electrical signals to electrochemical impulses that are further processed by the brain.
<span>Sexual reproduction is able to generate genetic variation in offspring because the process of meiosis
randomly shuffles genes across chromosomes and then randomly separates
half of those chromosomes into each gamete. The two gametes then
randomly fuse to form a new organism.</span>
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:
Ventral
Explanation:
This is because when you want to dissect a pig, it's back is place on a dissecting tray and it's belly side is up which is the ventral side. With the ventral side, dissection will be easy and the major organs and systems can be observed easily as they will be rightly viewed because they are obvious and rightly placed at belly side up.