Son preference in India, Pakistan, and China is evident due to their skewed sex ratios, driven by socio-cultural and economic factors:
Economic Dependence: Sons are often seen as economic assets, expected to support parents in old age, unlike daughters who traditionally marry and move to another household.
Cultural Beliefs: Sons are preferred for continuing the family name and performing last rites, which are considered important in many religions.
Gender Bias: Discriminatory practices, such as dowry and limited opportunities for women, reinforce the preference for male children.
Policy Impact: In China, the one-child policy amplified son preference, leading to selective births and gender imbalances.
On the same political outline map of India, two places related with the centres of revolt of 1857 one marked as A and B. Identify them and write their names on the lines marked near them.
(A) Delhi
(B) Calcutta
On the given political outline map of India, locate and label the following with appropriate signs:
(i) Amravati – Buddhist site
(ii) Varanasi – Ancient city
(iii) (a) Vijayanagara – An Empire of 14th century
OR
(iii) (b) Orissa – Territory of 14th century
Draw a rough sketch for the curve $y = 2 + |x + 1|$. Using integration, find the area of the region bounded by the curve $y = 2 + |x + 1|$, $x = -4$, $x = 3$, and $y = 0$.
Study the given molecular structure of double-stranded polynucleotide chain of DNA and answer the questions that follow. 
(a) How many phosphodiester bonds are present in the given double-stranded polynucleotide chain?
(b) How many base pairs are there in each helical turn of double helix structure of DNA? Also write the distance between a base pair in a helix.
(c) In addition to H-bonds, what confers additional stability to the helical structure of DNA?