Gender: The role of chromosomes Flashcards
What’s a chromosome?
Made from DNA
Males and females differ in a pair of chromosomes known as the sex chromosomes. Females have two X chromosomes (XX) in their cells, while males have one X and one Y chromosome (XY).
There are 46 chromosomes in the human body arranged into 23 pairs, the 23rd pair determined biological sex.
What’s a hormone?
Hormones are chemical messengers released from endocrine glands that influence the nervous system to regulate the physiology and behaviour of individuals.
What do hormones do prenatally (in the womb)?
Act upon brain development and cause the development of the reproductive organs.
What do hormones do during adolescence?
A burst of hormonal activity triggers the development of secondary sexual characteristics such as pubic hair.
What’s the chromosomal structure of females?
XX
What’s the chromosomal structure of males?
XY
What’s intersex?
A term used to describe an individual who is neither a male nor female because of a mismatch between chromosomes and genitals.
What’s the role of testosterone?
Believed to be responsible for typical male behaviours e.g. aggression, competitiveness and superior visuospatial abilities.
Males also have a surge of testosterone during puberty, and this is responsible for secondary sexual characteristics such as facial hair and deepening voice.
What’s the role of oestrogen?
One of the main female sex hormones. It is needed for puberty, the menstrual cycle, pregnancy, bone strength and other functions of the body.
Oestrogen levels vary throughout the menstrual cycle.
What’s the role of oxytocin?
Promotes feelings of bonding, contentedness and calm.
It is particularly important in breastfeeding to promote lactation and is released at times of stress to reduce the fight-flight response.
Females have higher levels of oxytocin than men, as oestrogen has been found to increase oxytocin secretion.
What’s Klinefelter’s syndrome?
Occurs due to an atypical sex chromosome pattern which affects the development of males who have an extra X chromosome (XXY).
Klinefelter’s syndrome is found in around 1 in 1,000 males.
The most common symptom is infertility, but males with Klinefelter’s syndrome may also have small, firm testes, a small penis, sparse pubic, armpit and facial hair, enlarged breasts (called gynecomastia), tall stature, and abnormal body proportions (long legs, short trunk).
What’s Turner’s syndrome?
Occurs due to atypical sex chromosome patterns and affects development in females who only have one X chromosome (XO); it occurs in 1 in 2,000 females.
The most common feature is short stature, which becomes evident by about age 5.
An early loss of ovarian function is also very common, so many affected girls do not undergo puberty unless they receive hormone therapy, and most are unable to conceive.
One-third to one-half of those with Turner syndrome are born with a heart defect. There is also a wide range of other symptoms such as a small lower jaw, webbed neck, narrow hips, and misshapen internal organs.
AO3 The role of chromosomes
+RLA
+ Support for the nature-nurture debate
-Oversimplification
-Deemed as a scientific justifications for discriminatory practices
(+AO3) RLA
Research into patients with Klinefelter’s Syndrome and Turner’s Syndrome has seen a development of therapies to improve the quality and duration of their lives.
For example, treating stunted growth often seen with Turner’s Syndrome by the application of growth hormones and the treatment of Klinefelter’s Syndrome with testosterone has seen those with the condition develop a less passive nature.
This is a strength because it shows that such research into gender in the field of psychology is having a positive effect on the human experience. In addition, such research has allowed for symptoms of these disorders to be effectively treated.
In line with the idea of sex-role stereotypes, through the mechanism of social learning theory, we could accuse society of encouraging individuals with
typically strong masculine or feminine characteristics to act as role models for young children, who would imitate these characteristics through the use of mediational processes (attention, retention, motivation and motor reproduction).
(+AO3) Support for the nature-nurture debate
The study of the influence of genes and hormones in gender development is a classic example of the Nature-Nurture debate.
In this case, the evidence seems to suggest that gender is primarily determined by biology but can be modified by social-environmental factors: for example, gender is expressed by men and women in different ways in different cultures, and notions of acceptable behaviours for the genders have changed dramatically in Europe over the past century (feminist and gender equality).
