The backbone of a polynucleotide chain is formed by:

Read the following passage carefully and answer the given questions
The earthworm is referred to as the farmer's friend. This is because they help in the breakdown of complex organic matter as well as in loosening of soil. Similarly, decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and nutrients and the process is called decomposition. Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter, constitute detritus, which is the raw material for decomposition. Some of the steps in the process of decomposition are fragmentation, catabolism, leaching, humification etc.
Which one of the following is not associated with earthworm as 'farmer's friend'?

Which one of the following represents a palindromic sequence?

Which one of the following hormones is essential for maintenance of endometrium?

Which one of the following statement is incorrect about ecological pyramids?

A nematode, Meloidogyne incognitia infects the roots of _______ and causes a great reduction in yield.

Match List-l with List-II

List - l (Terms)	List - lI (Features)
(A) Natality	(I) Exit of individuals
(B) Mortality	(II) Entry of individuals
(C) Immigration	(III) Death rate
(D) Emigration	(IV) Birth rate

Choose the correct answer from the options given below:

If \(P(A)=\frac{6}{11}, P(B)=\frac{5}{11}\) and \(P(A \cup B)=\frac{7}{11}\), then
A. \(P(A \cap B)=\frac{4}{11}\)
B. \(P(A \mid B)=\frac{ 4 }{ 5 }\)
C. \(P(B \mid A)=\frac{2}{5}\)
D. \(A\) and \(B\) are independent events
E. \(P(\) neither \(A\) nor \(B)=\frac{4}{11}\)
Choose the correct answer from the options given below:

Read the passage carefully and answer the Questions
The term vitamin was coined from the word vital +amine since the earlier identified compounds had amino groups. Later work showed that most of them didn't contain amino groups. They are very essential for the body. They has to be taken various diet or in the form of medicines also.
Vitamins are classified into two groups depending upon their solubility in water or fat.
Fat soluble vitamins are soluble in fat and oils but insoluble in water. Thhey are stored in liver and adipose (fat storing) tissues Water soluble vitamins are soluble in water. These must be supplied regularly in diet because they are readily excreted in urine and cannot be stored in our body.
Which among the following is not a fat soluble vitamin?

If \(x=2 a t, y=a t^2\), where ' a ' is a constant, then \(\frac{d^2 y}{d x^2}\) at \(x=2\) is :

If \(\theta\) is the angle between any two vectors \(\vec{a}\) and \(\vec{b}\), then \(|\vec{a} \cdot \vec{b}|=|\vec{a} \times \vec{b}|\) for \(\theta\) equal to __________.

Which of the following atoms has the lowest ionization energy ?

If the 8th bright band of wavelength \( \lambda_1 \) coincides with 9th bright band of wavelength \( \lambda_2 \) in a Young's double slits experiment then the possible wavelength of two lights are :