Are there biological reasons why life expectancy is lower for men in most countries of the world?
There are both biological and  social factor for that:
Biological

Females have two X chromosomes. When mutations in genes of the X chromosome occur, females have a second X to compensate. Males, on the other hand gave just one chromosome X and all genes its genes express themselves, even those lethal or deleterious.
Females have better resistance to biological aging and hormones and the role of women in reproduction are known to be associated to greater longevity (e.g. estrogen offers some protection against heart disease because it facilitates elimination of bad cholesterol while testosterone has been linked to violence and risk taking).
The female body evolved to accommodate the needs of pregnancy and breast feeding hence deals better with making reservation. This ability has been linked to a female's better ability to cope with overeating and eliminating excess food

Social
This &quot;advantage&quot; women seem to have was once nullified by the status and life conditions they had back then, as the risks and the burden of pregnancy and the lack of attention to health and rights women had in a way more misogynist world.
Given the economic, social and political changes that the world experienced, a general progress in female life conditions took place and women have not only regained their biological advantage, but have gone beyond it, achieving higher life expectation. Social and comportamental factor are involved in this higher longevity:

Women tend to engage in fewer risky and bad for health behaviors than men do, e.g. men have more problems than women with alcoholism, smoking and road accidents.
The world is still very sexist and the gender roles to be played would expose men to higher risks. Regarding to work, for instance, although women nowadays participate in the work force, their professional activities remain different and are less prejudicial to their health (on average).
Also regarding to  very sexist gender roles, men are expected to be strong and manly and powerful and women are expected to be gracious young and beautiful. As a result of that, women are more attentive to their body and health, engage themselves in more healthy activities and benefit more from medicine and science. Men on the other hand submit their bodies to challenges from early ages and tend to neglect their bodies needs.


You can have access to detailed statistics (male/female, country by country, life expectancy and other health data) here:
http://www.who.int/gho/publications/world_health_statistics/2016/Annex_B/en/
And also, read more about the issue here:
https://www.scientificamerican.com/article/why-is-life-expectancy-lo/
http://www.who.int/mediacentre/news/releases/2016/health-inequalities-persist/en/
https://en.wikipedia.org/wiki/List_of_countries_by_life_expectancy#cite_note-10