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It's 2026, (no longer 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, or 2025)
- Thread starter Bobcat
- Start date
fund razor
Founding Member
Looks like Karoline is going to leave it.
Ratickle
Founding Member / Super Moderator
Somebody should tell these idiots, including our one Supreme Court justice, about XX versus XY. They are simple tests, and extremely accurate.
Sex chromosomes are packages of DNA, that are found inside the nucleus of all of your cells. There are two different kinds: X and Y, which determine whether you’re biologically male (XY) or female (XX). Chromosomes themselves are made up of proteins and DNA that carry your genetic information from cell to cell.
When an egg is fertilized, the egg itself always contributes an X chromosome, while the sperm can contribute either an X or a Y. Sex chromosomes are the genetic elements that define a person’s biological sex.
Humans have 23 pairs of chromosomes, or 46 total, and 22 of these pairs are numbered chromosomes, known as autosomes. The 23rd pair is a pair of sex chromosomes (XX or XY).
Definitive methods (high accuracy)
Sex chromosomes are packages of DNA, that are found inside the nucleus of all of your cells. There are two different kinds: X and Y, which determine whether you’re biologically male (XY) or female (XX). Chromosomes themselves are made up of proteins and DNA that carry your genetic information from cell to cell.
When an egg is fertilized, the egg itself always contributes an X chromosome, while the sperm can contribute either an X or a Y. Sex chromosomes are the genetic elements that define a person’s biological sex.
Humans have 23 pairs of chromosomes, or 46 total, and 22 of these pairs are numbered chromosomes, known as autosomes. The 23rd pair is a pair of sex chromosomes (XX or XY).
Definitive methods (high accuracy)
- Karyotyping: Visualizes all chromosomes under a microscope after staining. Can confirm XX (female) or XY (male) with very high precision, though it requires cell culture and takes several days.
- Fluorescence in situ hybridization (FISH): Uses fluorescent probes to detect X or Y chromosomes quickly. More sensitive than karyotyping for detecting mosaicism or small abnormalities.
- PCR for SRY gene: Amplifies the SRY gene on the Y chromosome. Highly sensitive and can detect even small amounts of Y DNA, useful in prenatal or forensic cases.
