he Chargoff’s rule says that DNA contains equal amounts of guanine and cytosine and also equimolar amounts of adenine and thymine as: G= C and A= T
Does Chargoff’s rule imply that the sum of purine residues equals the sum of pyrimidine residues i.e. does `A+G =C+T` ?

he Chargoff’s rule says that DNA contains equal amounts of guanine and cytosine and also equimolar amounts of adenine and thymine as: G= C and A= T Does Chargoff’s rule imply that equal amounts of guanine and adenine are present in DNA?

A biologist studying the genetic code is interested to know the number of possible arrangements of 12 molecules in a chain. The chain contains 4 different molecules represented by the initials A (for Adenine), C (for Cytosine). G (for Guanine) and T (for Thymine) and 3 molecules of each kind. How many different such arrangements are possible in all ?

In a chamber, a uniform magnetic field of 6.5 G (1 G = 10–4 T) is maintained. An electron is shot into the field with a speed of 4.8 × 106 m s–1 normal to the field. (e = 1.6 × 10–19 C, me= 9.1×10–31 kg). Obtain the frequency of revolution of the electron in its circular orbit. Does the answer depend on the speed of the electron? Explain

f(x)=int_(0)^(x) (4t^(4)-at^(3)) dt and g(x) is quadratic satifying g(0)+6=g' (0)-c=g'' (c)+2b=0.y=h(x) and y=g(x) intersect in 4 distinct points with abscissae x_(i), i=1,2,3,4 such that sum(i)/(x_(i)) =8,a,b,c in R^(+) and h (x)=f' (x) . 'c' is equal to

f(x)=int_(0)^(x) (4t^(4)-at^(3)) dt and g(x) is quadratic satifying g(0)+6=g' (0)-c=g'' (c)+2b=0.y=h(x) intersect in 4 distinct points with abscissae x_(i), i=1,2,3,4 such that sum(i)/(x_(i)) =8,a,b,c in R^(+) and h (x)=f' (x) . 'a' is equal to