Recently in Latvia instead of the term “dzimums” (sex) often words like “social gender” or “gender” are used. The use and expedience of these words has aroused objections by linguists both in the biological and philosophical aspects. Are these objections indeed justified or do they imply only unwillingness to accept the new and sticking to the outdated? The article focuses on human biological and social interactions in the processes for maintaining reproduction including family functions. The spheres of application of the terms “sex” and “gender” are viewed, as well as the outcome of the free interpretation of these terms.