Sex ratio denotes the ratio of males to females in a population. The primary sex ratio is the ratio at the time of conception, secondary sex ratio is the ratio at time of birth, and tertiary sex ratio is the ratio of adult human beings. According to CIA estimates the current world sex ratio at birth is 107 boys to 100 girls. In 2010 the global sex ratio was 986 females to 1000 males, which got further reduced to 984 females to 1000 males in 2011.

The male to female human sex ratio varies, due to demographics, environment, sex deterministic abortion, and imbalance in the male/female sperm viability ratio. The secondary ratio of boys to girls is about 105 to 100, or about 0.525 male. Estimates of the current birth sex ratio is about 0.535 male. The current global sex ratio (population) is about 0.507 male (2010) to 0.508 male (projected 2011).

Sex ratio is ratio of males to females in a population.

23 chromosomes for every 1 sex cell??

Sex ratio refers to the proportion of males and females in a population or vice versa.