Choose the correct alternative.
Restriction endonuclease/exonuclease attaches itself between the same two bases on the opposite strands and causes break in the two.

Choose the correct alternative: Earthworm has two/four paris of lateral hearts.

Which of the following figures lie on the same base and between the same parallels. Insuch a case, write the common base and the two parallels.

State whether True or False. Correct the statements. Distance between the two parallel sides of the trapezium is called the base of the trapezium.

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : A cirlar wire has resistane R. Then its resistance between two diametrically opposite points will be R/4 . Reason : The two semicircular portions, each having resistance R/2, form a parallel combination

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : There are two values of angular frequency symmetrical about resonant angular frequency, for which same current can fow in an LCR-circuit. Reason : The two angular frequencies are given by omega _1 = 1 //sqrt(LC) and omega_2 = sqrt(LC)

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : The e.m.f. of a cell is always greater than the terminal potential difference between its two pole. Reason: There is always some potential drop across the internal resistance of the cell.

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : A proton and an alpha particle having the same kinetic energy are moving in ircular paths in a uniform magnetic field. the radii of the ciruclar paths will be equal Reasons: Any two charged particles having equal kinetic energies and entering a region of uniform magnetic field vecb in a direction perpendicualr to the vecb , will describe circular trajectories of equal radii.

True/False Two parallelograms are on the same base and between the same parallels. The ratio of their areas is 1:2.

A plasmid DNA and a linear DNA (both of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis, plasmid shows one DNA band while linear DNA shows two fragments. Explain.