Flowers and their insect pollinators are a classic example of coevolutionnnn
Answer:
The ability of sequences within the leader mRNA to pair with one another and form stem-lopp structures
Explanation:
A form of feedback regulation controls the trp operon by regulating transcription termination, a mechanism referred to as Attenuation.
-In the presence of high concentrations of tryptophan, RNA polymerase ceases transcription shortly after initiation in a region called the leader sequence.
-If the concentration of tryptophan is low, transcription does not terminate until the entire operon is transcribed. The mechanism of attenuation links alternative RNA secondary structures to transcription termination.
-Immediately after transcription, RNA from the leader region folds into one of two alternative secondary structures.
-One of these structures is a transcription termination signal that stops RNA polymerase from continuing to the end of the operon.
-The alternative structure does not contain a transcription termination signal and allows transcription of a single mRNA that encodes all the structural genes.
-The decision as to which of the two alternative RNA structures formed is regulated by the concentration of tryptophan.
Mendel concluded that pea traits like flower color were determined by separate units. From the results, Mendel proved that all traits do not blend. For instance, purple flowers mixed with white flowers did not produce pink flowers.
Since all of the offspring have the purple phenotype, this tells us that the purple allele is dominant to the white allele. ... This means that 75% of the offspring displayed the dominant phenotype of purple flowers, and 25% displayed the recessive phenotype of white flowers.
Two pea plants, both heterozygous for flower color, are crossed. The offspring will show the dominant purple coloration in a 3:1 ratio. Or, about 75% of the offspring will be purple.
Mendel's Results
Mendel noted the ratio of white flowered plants to purple-flowered plants was about 3:1. That is, for every three purple-flowered plants, there was one white flowered plant.
Marshmallows are probably so delicious because of several important factors. They are fluffy, soft, and oh-so sweet. They melt in your mouth and taste absolutely heavenly with chocolate and graham crackers. Or throw a couple in your hot chocolate. There's no wrong way to eat them and they're pretty cheap too.
