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The lac operon is found only in prokaryotes and consists of structural genes and a promoter and operator. Which of the following statements explains why we study the lac operon?

Correct Answer: It represents a principal means by which gene transcription can be regulated.
Remember that operons are found in prokaryotes, not higher organisms. However, higher animals may utilize a similar mechanism. For the same reason, you must eliminate Choice B. Operons are a means of controlling transcription of genes, whereas Choice C focuses on what happens after transcription. Operons have nothing to do with the cell cycle.

Consider the following statements and choose the correct answer:
1. The structural genes direct the synthesis of cellular proteins through messenger RNA (mRNA)
2. The promoter gene determines whether or not the structural genes are to be repressed by the repressor
3. The regulator gene directs the synthesis of a protein which may be an active repressor or an inactive repressor

If there is an insertion mutation in the operator of the lac operon, the expression of the lac structural gene will be __________

The lac operon consists of ____ structural genes.

A,B,C,D,E,G and I are seven friends who study in three different standards namely 5th, 6th and 7th such that not less than two friends study in the same standard. Each friend also has a different favorite subject namely History, Civics, English, Bangla, Science , Maths , and Economics but not necessarily in the same order. A likes Maths and studies in the 5th standard with only one other friend who likes Bangla. I studies with tow other friends . Both the friends who study with I like languages (Here languages include only Science , English and Bangla ) . D studies in the 6th standard with only one person and does not like Civics . E studies with only one friend . The one who likes history does not study in 5th or 6th standard . E does not like languages. C does not like English , Science or Civics. Which combination represents E's favorite subject and the standard in which he studies?

The lactose (lac) operon of the bacterium E. coli has which of the following structural genes?

Consider the following statements regarding the theory of linkage and choose the correct answer:
1. Genes are arranged in a linear fashion in the chromosomes
2. Genes that show linkage are situated in the chromosome
3. Linked genes remain in their original combination during the course of inheritance
4. The genes which are widely separated show strong linkage, while those closely located, have more chances to get separated by crossing over

How many structural genes are present in a lac operon?

Consider the following statements and choose the correct answer:
1. In the phenomenon of linkage and crossing over, the genes are arranged in a linear order in a chromosome
2. The linkage groups in an organism are equivalent to the number of chromosome pairs
3. The chances of crossing over are more between two closely placed genes as compared to the genes placed in far proximity
4. The position of genes is very definite in the chromatid

In an experiment of determining the order of gene in bacteria we use HFR which is gal+, Lac+, Ara+ and His+. If the recipient is negative for all these genes, and we selectively choose Gal + and get the pattern- 100 % recipients are Gal + 30% are His+ 55% are Lac + And only 5% are Ara+ What would be our inference?

Once an operon structure is known ______ for the presence of a promoter and regulatory elements _____ in the operon do not possess such DNA elements.