Sex Flashcards
Gametes
Mature reproductive cells made by gonads (ovaries or testes). They are either ova (egg cells produced by ovaries) or sperm (produced by testes.
Unlike all other cells in your body, which typically have 23 pairs of chromosomes (23 from your biological mother and 23 from your biological father), gametes only have one copy of each _____ (a mix from your mother and father).
Chromosomes
One pair of chromosomes are called the ___ chromosomes, as they usually determine the organism’s sex. They come in X and Y varieties.
Sex
Five factors present at birth typically used to determine an animal’s biological sex
- Sex chromosomes: XX or XY
- Gonads: testes or ovaries (internal, but develop with separate signaling cascade)
- Sex hormones: androgen signaling
- Internal reproductive anatomy
- External anatomy
3 categories of sex organs
Gonads, internal reproductive anatomy, external anatomy
Atypical combinations give rise to ____ conditions, in which the person cannot be distinctly identified as male or female.
Intersex
True or false : All embryos contain precursors for both female and male sex organs.
True
Undifferentiated gonads
Embryonic precursor of ovaries/testes.
Müllerian system
Embryonic precursors of female internal sex organs
Wolffian system
Embryonic precursors of male internal sex organs
True or false : both of the Mullerian and Wolffian systems are present in all embryos.
True
During the ____ month of gestation, the undifferentiated gonads typically develop into ovaries or testes. They will start releasing hormones
2nd
During the ____ month of gestation, typically either the Müllerian or Wolffian system develops while the other withers away based on the released hormones starting from the 2nd month.
3rd
The SRY gene is normally located on the _chromosome
Y
SRY gene encodes a protein that causes undifferentiated fetal gonads to develop into ____.
Testes
If the SRY gene is present, it is _____over XX instructions
Dominant (XXY individuals develop testes)
Defeminization : At 2nd month, embryonic testicular release of _____ hormone
Anti-mullerian
What prevents female Mullerian system from developping ?
Anti-mullerian release from testes
Masculinization
Effect of androgen hormones early in development, which triggers development of male-typical anatomy (wolffian system).
Androgen
male sex hormone.
Testosterone
Principal mammalian androgen. I
It is released by the testes, and it triggers development of the Wolffian system (internal male sex anatomy).
Testosterone
Some testosterone is converted into ________, which is what triggers development of external male sex anatomy.
Dihydrotestosterone
XX chromosomes develops functional ____
Ovaries
Developed ovaries are largely silent until _____.
Puberty
True or false : ovaries do NOT release molecules in the embryo
True
In the absence of _______ signaling, the Mullerian system develops into internal female reproductive anatomy, which includes the inner vagina, uterus, and fallopian tubes.
Anti-Mullerian
In the absence of testosterone signaling, external female sex organs (vulva) develop while the _____ system withers away
Wolffian
Puberty is triggered by _____ released from gonads (for both testes and ovaries in male and female).
Hormones
Turner Syndrome
When you only have one sex chromosome (X-). Born with only 45 chromosomes, no functional ovaries nor testes. You have external female sex organ.
Swyer Syndrome
XY but have a bad SRY gene, female external organs develop. No gonads.
What happens when you have no gonads ?
People without gonads are infertile. They also do not naturally experience puberty, but that is easy to artificially induce with hormone injections.
It is possible to have two (or more) X chromosomes as well as the SRY gene (e.g., XXY or XXXY). This usually results in typical ….
male development patterns (but also infertility).
Insufficient anti-Müllerian hormone
Will cause insufficient anatomical defeminization: both male and female internal sex organs will develop and get tangled together. There is often functional external male genitalia.
Androgen insensitivity syndrome
Anatomical defeminization with partial or no masculinization. In severe cases, no internal sex organs develop. In these cases, people typically develop normal external female genitalia and identify as heterosexual women, but they will be infertile and have a short vagina.