Chromosomes are thread-like molecules that carry hereditary information for everything from height to eye color. They are made of protein and one molecule of DNA, which contains an organism's genetic instructions, passed down from parents. In humans, animals, and plants, most chromosomes are arranged in pairs within the nucleus of a cell.
How the sex of offspring is determined has puzzled philosophers and scientists for millennia. Modern science has identified both genetic and environmental factors, but the question is still not yet fully answered. Of all the differences that distinguish people, the most obvious and most intriguing one is their sex.
Republish our articles for free, online or in print, under Creative Commons licence. If you were to conduct a survey, most people would probably have little difficulty expressing some fundamental differences. After all, we learn to tell boys apart from girls in early childhood.
In the end, families are happy to welcome their healthy new addition regardless of sex. The process through which gender is determined is called human sexual differentiation. All eggs contain an X chromosome, while sperm can have an X or a Y chromosome.
This page has been archived and is no longer updated. Whether an animal will become a male, a female, or a hermaphrodite is determined very early in development. Scientists have worked for hundreds of years to understand the sex-determination system.
Skandhan and Jasmine Japee. Abstract The fact that male gamete possesses either of sex chromosome, he is known responsible for gender of baby. All changes to millions of his gametes in female system from killing many, lifting, transporting, activating, permitting for its motility like processes done by her genital tract are responsible for preference of either X or Y chromosome carrying spermatozoan for fertilization.
Chromosomes are long segments of genes that carry hereditary information. They are composed of DNA and proteins and are located within the nucleus of our cells. Chromosomes determine everything from hair color and eye color to sex.
Sexual differentiation in humans is the process of development of sex differences in humans. It is defined as the development of phenotypic structures consequent to the action of hormones produced following gonadal determination. The development of sexual differences begins with the XY sex-determination system that is present in humans, and complex mechanisms are responsible for the development of the phenotypic differences between male and female humans from an undifferentiated zygote. At an early stage in embryonic development, both sexes possess equivalent internal structures.
A Newcastle University study involving thousands of families is helping prospective parents work out whether they are likely to have sons or daughters. The work by Corry Gellatly, a research scientist at the university, has shown that men inherit a tendency to have more sons or more daughters from their parents. This means that a man with many brothers is more likely to have sons, while a man with many sisters is more likely to have daughters.