Gender and Sexual Behaviour Flashcards
What are the benefits of sexual reproduction?
- Reduces chance of passing on mutations
- Gives diversity
- Allows for survival of the fittest
What is the difference between sex and identity?
Sex = our genetic makeup (our hormones and internal and external genitalia)
Gender = our social role/identity (socially constructed norms and ideals, can be changed over times and across cultures.
What is XX intersex?
The individual has the chromosomes of a women, ovaries of a woman, but external genitalia appear male - this is because of an excess of male hormones before birth.
What is XY intersex?
The individual has the chromosomes of a man but external genitalia is incompletely formed, ambiguous, or appear female. Internal testes may be malformed or absent, problems with testosterone formation and testes.
What is the difference between DNA and genes?
DNA is the base of all genes and genes are just the parts of DNA.
What are chromosomes?
These are how DNA are organised.
How do chromosomes show if we are male or female?
The 23rd pair of chromosomes genetically define whether we are male or female by assigning us with an X or Y chromosome.
What is the y chromosome?
This dictates male sexual development (the testes and hormones). The sex determining region activates a number of genes and the gonads develop as testes.
What are gametes?
Egg and sperm
What are gonads?
Glands that make gametes
Colour blindness and genes?
The chances of girls being colour blind are really low as the father must be colour blind and the mother must be at least a carrier whereas it is a lot more likely for me.
What is turners syndrome?
The second X chromosome is altered or missing. This only affects females and is not inherited. The ovaries do not work properly as oestrogen and progesterone are limited which means they require hormone replacement therapy and they may not have periods
What are physical traits of turners syndrome?
- Shorter than average
- Wider neck
- puffy hands
- Weaker bones
- Hearing difficulties
What is Klinefelter syndrome?
- Additional X chromosome
- Chromosomal disorder in males
- Do not produce enough testosterone
- Often do not make any sperm - infertile
- Can have increased learning and behavioural difficulties
- Hormone replacement therapy can encourage muscle strength, body hair, reduce fat on abdomen, encourage stronger bones.
- Often appear more female than male
How does sexual development occur in precursor organs?
If we have a Y chromosome the Wolffian duct develops into the male internal reproductive system and the Mullerian duct is prevented from developing by the anti-Mullerian hormone.
If no Y chromosome - Mullerian duct develops into female reproductive system and the Wolffian duct degenerates.
This happens after 6 weeks from conception.
What are gonadotropin-releasing hormones (GnRH)?
The hypothalamus releases gonadotropin-releasing hormones (GnRH), controlling the secretion of the luteinizing hormone (LH) and follicle stimulation hormone (FSH). In woman LH and FSH encourage oestrogen production. In men FSH matures sperm cells and LH encourages testosterone. Lower melatonin increases gonadotropic secretion so that offspring are born when they have the most chance of survival.
Explain the hormonal control of sex.
Pituitary glands regulate the release of steroid sex hormones:
- Ovaries release oestrogen and progesterone
- Testes release testosterone
Men have female hormones and females have male hormones too, just in different concentrations.
What has Anne S shown us about sexual development?
She was born chromosomally male with internalised testes and hormone levels of a man but she had testosterone insensitivity syndrome, but did respond to oestrogen. This shows that feminisation is the default route for development in regards to appearance due to lack of neonatal androgen.
What is testosterone?
- Essential for development of male reproductive system
- At puberty regulates the development of sex characteristics such as muscle development and facial hair
- Females have 10% of that found in men
- Hormone levels fluctuate throughout the day, are affected by stress, exertion, and aggression
What are problems of using testosterone as a form of doping?
- Increased incident of cardiovascular disease
- Acne
- Hair loss
- Potential prostate cancer risk
What are oestrogen and progesterone?
These control maturation fo the female reproductive system and development of breasts
- Have cycles of about 28 days
- Levels are low during childhood and then increase dramatically at puberty
What differences are there in brain structures of females and males?
Females are said to have larger hippocampus and smaller amygdala, but this study is flawed so cannot completely trust results.
What is the sexually dimorphic nucleus (SDN)?
This is a preoptic area of the anterior hypothalamus. This is related to sexual attraction as it seems gay men have a smaller nucleus. although the causal relationship is unclear.
How do males and females show different sexual behaviour and why?
- sperm are mobile - males tend to be more mobile and go out and find a mate because they can get a lot more people pregnant without having any personal consequences.
- females are a bit pickier - they have a limited chance of pregnancy so want good quality partner
- Men show off more - louder, larger, more combative
- polygyny is very common among mammals whereas polyandry is rare eg. one alpha male lion and several female lions is common
