- the proportional distribution of the sexes in a population aggregate, expressed as the number of males per 100 females.
Origin of sex ratio
First recorded in 1905–10
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for sex ratio
A modification of the sex-ratio and of other ratios through linkage.
The former are always normal in behavior, and the latter repeat in their descendants the 2:1 sex-ratio.
From an F2 culture that gave practically a 2:1 sex-ratio, vermilion females were bred to club males.
Two sex-linked lethal factors in Drosophila and their influence on the sex-ratio.
- The proportion of males to females in a given population, usually expressed as the number of males per 100 females at a specific stage in life, especially at conception, birth, and a given stage between birth and death.
- The ratio of the numbers of males to females affected by a particular disease or trait.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.