The sex ratio is a significant demographic indicator that provides insights into the gender composition of a population. It is defined as the number of males per 100 females in a given population. The sex ratio can vary across countries, regions, and even within different age groups. Let's explore the world pattern of sex ratio with examples.

1. Global Sex Ratio:
- The global sex ratio is approximately 101 males per 100 females, indicating a slight preponderance of males.
- However, this ratio can vary significantly among different countries and regions.

2. High Sex Ratio:
- Some countries have a higher sex ratio, indicating a higher number of males compared to females. For example:
- China: Due to cultural preferences for male children and the one-child policy, China has a high sex ratio, particularly among the younger population.
- India: Similarly, India also experiences a high sex ratio due to cultural preferences for male children and gender-based discrimination, leading to sex-selective practices.

3. Low Sex Ratio:
- Conversely, some countries have a lower sex ratio, indicating a higher number of females compared to males. For example:
- United Arab Emirates (UAE): The UAE has a low sex ratio due to a large number of male migrant workers compared to the female population.
- Russia: Russia has a lower sex ratio due to higher male mortality rates, particularly among working-age males.

4. Natural Factors:
- Natural factors can also influence the sex ratio. For instance:
- In many countries, the sex ratio is slightly higher at birth, with around 105 males born per 100 females. However, this ratio tends to equalize as individuals age due to higher male mortality rates.
- War and conflict can also lead to imbalances in the sex ratio, as more males are involved in combat and are at higher risk of mortality.

5. Age-specific Sex Ratio:
- Sex ratios can also vary within different age groups. For example:
- In many countries, the sex ratio is higher among younger age groups due to factors like gender-based discrimination, migration patterns, and cultural preferences for male children.
- On the other hand, the sex ratio tends to be lower among older age groups due to higher female life expectancy.

In conclusion, the world pattern of sex ratio varies across countries, regions, and age groups. Cultural, social, economic, and natural factors contribute to these variations. It is important to monitor and analyze sex ratios to understand demographic trends and address any gender imbalances or disparities.