The exercise tells you to complete the table showing different cases of mutation in different parts of the operon.
First, what is an operon?An operon is a genetic unit of coordinated expression. It comprises a group of adjacent structural genes encoding the enzymes of the same metabolic pathway, as well as the regulatory sequences affecting the transcription of these structural genes (like operon lactose or tryptophan). It is composed by:
Structural genes/cistrons: code for the enzymes participating in the same metabolic pathway, they are co-transcribed into a single polycistronic mRNA.
• Promoter common to all structural genes: this is the binding site of RNA polymerase.
• The operator: it is a regulatory sequence, it is the site of binding of the protein of the regulation, it controls the transcription of the gene downstream.
• The regulatory gene: located upstream of the operon promoter, it encodes regulatory proteins capable of binding on the operator. He owns his own promoter.
*If a mutation touch one of the genes that the operon code for, this gene will be not functional
*If a mutation touches the operator none of the enzymes will be synthesized
*If a mutation touches a repressor (a molecule which inhibits the expression of the operon genes by binding specifically to the DNA at the operator level).
Based on this, the right answers are:
Mutant 1 ==> gene A
Mutant 2 ==> repressor
Mutant 3 ==> gene B
Mutant 4 ==> promoter
Answer:
The above mentioned description is true for the members of kingdom Fungi. A eukaryotic organism characterized by the presence of chitin in its cell wall is called fungi. Some of the defining features of this group include the absence of chloroplast, presence of nuclei that are membrane-bound, production of spores and presence of hyphae.
Explanation:
The members of this kingdom are non motile and posses the property of decomposes. Besides it helps in the process of nutrient cycling and its exchange as it is a decomposer. The presence of chitin in their cell wall is the unique feature of the fungi that explains its presence in a separate kingdom. They are heterotrophic in nature and perform symbiotic associations. They have the ability to secrete digestive enzymes that helps in the absorption of dissolved molecules. They also serve the purpose of decomposers in the ecosystem. They have the ability to reside in extreme environments.
Answer:
Nothing will happen.
Explanation:
Nothing will happen to the octopus population if the number of snails decreased or extinct in the area because there are many other organisms on which octopus can feed. Octopuses feed on crabs, small fishes, clams, snails, and on other octopuses so if other food sources are available to Octopus so there is no effect on the Octopus population but if there is no other food source then the Octopus population will definitely decreases due to lack of food.
Carbon has an atomic number of 6.