Gender and Sexual Behaviour

Question 1

What are the benefits of sexual reproduction?

Answer 1

• Reduces chance of passing on mutations
• Gives diversity
• Allows for survival of the fittest

Question 2

What is the difference between sex and identity?

Answer 2

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.

Question 3

What is XX intersex?

Answer 3

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.

Question 4

What is XY intersex?

Answer 4

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.

Question 5

What is the difference between DNA and genes?

Answer 5

DNA is the base of all genes and genes are just the parts of DNA.

Question 6

What are chromosomes?

Answer 6

These are how DNA are organised.

Question 7

How do chromosomes show if we are male or female?

Answer 7

The 23rd pair of chromosomes genetically define whether we are male or female by assigning us with an X or Y chromosome.

Question 8

What is the y chromosome?

Answer 8

This dictates male sexual development (the testes and hormones). The sex determining region activates a number of genes and the gonads develop as testes.

Question 9

What are gametes?

Answer 9

Egg and sperm

Question 10

What are gonads?

Answer 10

Glands that make gametes

Question 11

Colour blindness and genes?

Answer 11

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.

Question 12

What is turners syndrome?

Answer 12

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

Question 13

What are physical traits of turners syndrome?

Answer 13

• Shorter than average
• Wider neck
• puffy hands
• Weaker bones
• Hearing difficulties

Question 14

What is Klinefelter syndrome?

Answer 14

• 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

Question 15

How does sexual development occur in precursor organs?

Answer 15

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.

Question 16

What are gonadotropin-releasing hormones (GnRH)?

Answer 16

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.

Question 17

Explain the hormonal control of sex.

Answer 17

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.

Question 18

What has Anne S shown us about sexual development?

Answer 18

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.

Question 19

What is testosterone?

Answer 19

• 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

Question 20

What are problems of using testosterone as a form of doping?

Answer 20

• Increased incident of cardiovascular disease
• Acne
• Hair loss
• Potential prostate cancer risk

Question 21

What are oestrogen and progesterone?

Answer 21

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

Question 22

What differences are there in brain structures of females and males?

Answer 22

Females are said to have larger hippocampus and smaller amygdala, but this study is flawed so cannot completely trust results.

Question 23

What is the sexually dimorphic nucleus (SDN)?

Answer 23

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.

Question 24

How do males and females show different sexual behaviour and why?

Answer 24

• 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

Question 25

How does sexual arousal arise?

Answer 25

• Psychological stimulation (top down)
• Sensory stimulation (top down)
• Tactile stimulation (bottom up)

Question 26

How do we control sexual response?

Answer 26

The cortex and spinal chord regulate response.

Question 27

How does the sexual response cycle vary between sexes?

Answer 27

Men have a longer resolution phase - takes longer before they can have an orgasm again.

Question 28

How does an erection work?

Answer 28

A spinal reflex causes blood to flow into the penis. The erection is controlled by the parasympathetic division of the ANS. Nerve endings widen arteries by releasing acetylcholine, vasoactive intestinal polypeptide, and nitric oxide

Question 29

How does Viagra work?

Answer 29

It interferes with the nitric oxide metabolic pathway

Question 30

What is the brain location of the orgasm?

Answer 30

Some studies have found the medial temporal lobe and basal forebrain to show up in sexual arousal, but it is hard to measure as everyone has different orgasms.

Question 31

Which hormones increase pair bonding and encourage monogamy?

Answer 31

Oxytocin and vasopressin. These interact with the reward system meaning that partner bonding stimulates the feeling of a reward.

Question 32

What has the study of voles shown as about monogamy?

Answer 32

This can only be encouraged by administering vasopressin and oxytocin if the strong reference for an individual is already there, they need to have receptors in place in order to encourage pair bonding.

Question 33

What did De Jonge find about estrogen and progesterone in rats?

Answer 33

Progesterone facilitates the effect of oestrogen so both of these work together to encourage reproduction.

Question 34

What is the relationship between sexual attraction and ovulatory cycle?

Answer 34

When females are fertile they are seen as more attractive, but for pill users this seems to have a denounced effect.

Question 35

What did the STM show in terms of mating behaviour?

Answer 35

A more masculine face infers that the person is less of a friend and more of a lover.

Question 36

What does the LTM show about mating behaviour?

Answer 36

This individual is a balance of a friend and a lover as the yare between having a very masculine and very feminine face.

Question 37

How does the hypothalamus differ in heterosexual and homosexual people?

Answer 37

The anterior hypothalamus is smaller in those attracted to men.