Although there seems to be only one gene that controls whether or not people taste bitterness there are more than two possible alleles at this gene locus. Therefore, there are more than two different possible allelic combinations, but people with the gene present will taste bitterness to the same extent.

One of the SNPs of a certain bitter taste receptor (TAS2R38) was investigated by PCR-RFLP method using the Fnu4H I restriction endonuclease. If the C allele is present as a template, the enzyme cleaves the PCR product amplified from it at the SNP, and the PCR product always contains two additional non-polymorphic cleavage sites. In the upper, schematic part of the figure, the cleavage sites in the expected PCR product are shown by bold arrows, and the distances between them and from the ends are shown by numbers. The lower part of the figure shows the final results of a series of experiments. Select the correct statement(s).Question 2Answer1.A technical error occured during the experint, because the PCR product of 331 + 75 + 21 + 41 = 468 bp is not visible in any lane.2.The DNA molecules migrate from the loading wells towards the positive pole during the gel electrophoresis.3.The lower part of the figure shows the results of a horizontal agarose gel electrophoresis.4.In lane No. 4 a sample of a heterozygous person with CT genotype ran.

Which evidence supports labeled line coding in the taste system?Group of answer choicesIncreasing concentrations of tastants can overcome a genetic mutation that results in a deficiency of taste receptors.The same behavioral responses are observed in response to all tastants when specific taste receptors are inactivated.No change in cranial nerve activity is observed when specific taste receptors are inactivated.Mice re-expressing PLCb2 in T2-expressing taste cells in a PLCb2 mutant mouse are able to respond to bitter tastes.Receptor proteins re-expressing are expressed broadly in taste cells and not in subsets

Our sensation of taste is transmitted through taste buds. How are these distributed on the tongue?Group of answer choicesThe different taste buds are all located in the same areas of the tongue.The tip, the sides, and the back of the tongue all sensitive to different taste sensations.The tip of the tongue is sensitive to sweet, the sides closest to the tip is sensitive to salty, the sides farthest from the tip are sensitive to sour, and the back is sensitive to bitter.The tip of the tongue is sensitive to sweet, the sides are sensitive to salty and sour, and the back is sensitive to bitter.The tip of the tongue is sensitive to sweet, the sides are sensitive to salty and sour, the back is sensitive to bitter, and the middle is sensitive to spicy.

Which of the following is false about gustation?A) The six basic tastes found in vertebrates are bitterness, sweetness, saltiness, sourness, fatand umami.B) Gustation help us identify the stimuli in our mouths.C) Lingual lipase enzyme breaks down proteins into fatty acids.D) The enzyme lingual lipase is located near the taste buds in the mouth.E) Alkaloids taste bitter (can be poisonous) and acid tastes sour.

Which taste quality primarily involves the detection of glutamate and the tasting of proteins, andis associated with the savory taste often found in foods like meat and cheese?a) Sournessb) Umamic) Sweetnessd) Saltinesse) Bitterness