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. Humans have 22 of these chromosome pairs, called autosomes. Humans have an additional pair of sex chromosomes for a total of 46 chromosomes. The sex chromosomes are referred to as X and Y, and their combination determines a person's sex.
Chromosomes: Definition & Structure
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Geneticists make new discovery about how a baby's sex is determined -- ScienceDaily
Medical researchers at Melbourne's Murdoch Children's Research Institute have made a new discovery about how a baby's sex is determined -- it's not just about the X-Y chromosomes, but involves a 'regulator' that increases or decreases the activity of genes which decide if we become male or female. An embryo with two X chromosomes will become a girl, while an embryo with an X-Y combination results in a boy," Ms Croft said. High levels of the SOX9 gene are needed for normal testis development. Lead author of the study, Professor Andrew Sinclair, said that 90 percent of human DNA is made up of so called 'junk DNA or dark matter' which contains no genes but does carry important regulators that increase or decrease gene activity. If these enhancers that control testis genes are disrupted it may lead to a baby being born with a disorder of sex development. Professor Sinclair, who is also a member of the Paediatrics Department of the University of Melbourne, said this study sought to understand how the SOX9 gene was regulated by enhancers and whether disruption of the enhancers would result in disorders of sex development. Ms Croft said human sex reversal such as seen in these cases is caused by gain or loss of these vital enhancers that regulate the SOX9 gene; consequently, these three enhancers are required for normal testes and male development.
Genetic Mechanisms of Sex Determination
This page has been archived and is no longer updated.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.
Not intercourse, though — more about how genetic sex is programmed during development. Sexual identity has been in the news often lately, and unsurprisingly so: the past few years have yielded sweeping reforms in civil rights, spurring new conflicts surrounding everything from age-old battles in gender equality to legislation enforcing anti-transgender bathrooms. Most multicellular organisms, humans included, use sexual reproduction to reproduce.
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The real enemy is the Thalmor.
She could feed a small village.
Such a nasty slut Such a misleading title...
This looks pro shot.
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