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E. coli cells with a mutated z gene of the lac operon cannot grow in a medium containing only lactose as the source of energy because-
A beam of cathode rays is subjected to crossed Electric (E) and magnetic fields (B). The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by:
A metallic bar of Young's modulus $0.5 \times 10^{11}\text{ N m}^{-2}$, coefficient of linear thermal expansion $10^{-5}\ ^\circ\text{C}^{-1}$, length $1\text{ m}$ and cross-sectional area $10^{-3}\text{ m}^2$ is heated from $0^\circ\text{C}$ to $100^\circ\text{C}$ without expansion or bending. The compressive force developed in the metallic bar is:
Match List I with List II regarding the lac operon genes and their products: List I (Genes) List II (Products) A. Gene 'a' I. Beta-galactosidase B. Gene 'y' II. Transacetylase C. Gene 'i' III. Permease D. Gene 'z' IV. Repressor protein
Length cannot be measured by
Identify the correct statement:
The method used to remove temporary hardness of water is :
Given below are two statements: Statement I: DNA polymerases catalyse polymerisation only in one direction, that is 5' →3' Statement II: During replication of DNA, on one strand the replication is continuous while on other strand it is discontinuous. In the light of the above statements, choose the correct answer from the options given below:
If a DNA molecule is shortened by 25 base pairs, how many helical turns will be reduced from its structure?
The sequence that controls the copy number of the linked DNA in the vector, is termed
During DNA replication, Okazaki fragments are used to elongate:
A cup of coffee cools from $90^{\circ}\text{C}$ to $80^{\circ}\text{C}$ in $t$ minutes, when the room temperature is $20^{\circ}\text{C}$. The time taken by a similar cup of coffee to cool from $80^{\circ}\text{C}$ to $60^{\circ}\text{C}$ at room temperature same at $20^{\circ}\text{C}$ is:
Forelimbs of cat, lizard used in walking; forelimbs of whale used in swimming and forelimbs of bats used in flying are an example of:
Among fraternal twins, one baby is haemophilic while the baby's brother is normal. Which statement is true?
Which one of the following is a wrong matching of a microbe and its industrial product, while the remaining three are correct?
RNA and DNA are chiral molecules, their chirality is due to:
The length of the DNA molecule greatly exceeds the dimensions of the nucleus in eukaryotic cells. How is this DNA accommodated?
Given below are two statements : Statement I: Sickle cell anaemia and Haemophilia are autosomal dominant traits. Statement II: Sickle cell anaemia and Haemophilia are disorders of the blood. In light of the above statements, choose the correct answer from the options given below :
Which enzyme(s) will be produced in a cell in which there is a non-sense mutation in the lac Y gene?
The correct order of atomic radii in group 13 elements is