a segment of DNA that can move from one place to another in a cell's genome or between a bacterial cell and a plasmid or virus. Viruses may even carry a transposon from one bacterium to another. Also called jumping gene, transposable element. segment of DNA that can move from one place to another in a cell's genome or between a bacterial cell and a plasmid or virus. Viruses may even carry a transposon from one bacterium to another. Also called jumping gene, transposable element.
Women with a low body weight, are frequently under high stress, or in perimenopause tend to have irregular periods. These women have very low estrogen production, so the body has trouble communicating to the ovaries that eggs need to be released, and ovulation does not take place.
As a woman ages and especially as she gets closer to menopause, her ovaries get smaller. This time of changes in hormone levels and menstrual cycles is called the menopausal transition. You might also hear it called perimenopause. It usually lasts several years until 12 months after your last period. Once a woman has gone a full 12 months without a period, she can be fairly sure that she has been through menopause and is now in postmenopause.