The role of chromosomes and hormones

Question 1

What are chromosomes?

Answer 1

Found in the nucleus of living cells and carrying information in the form of genes.
-> 23rd pair of chromosomes determines biological sex.

Question 2

What are genes?

Answer 2

Short sections of DNA that determine the characteristic of a living thing.

Question 3

How many chromosomes in the human body?

Answer 3

46; 23 pairs.

Question 4

What is the chromosome pattern for females?

Answer 4

XX

Question 5

What is the chromosome pattern for males?

Answer 5

XY

Question 6

How is a baby’s sex determined?

Answer 6

-All eggs carry the X chromosome and sperm carries either X or Y.
-The babies sex is determined by the sperm that fertilises the egg (if it’s carrying an X or Y chromosome).

Question 7

What does the Y chromosome carry?

Answer 7

Carries a gene called the ‘sex determining region Y’ or SRY for short.

Question 8

What is the SRY?

Answer 8

A gene which cases testes to develop in an XY embryo and produce androgens (male sex hormones).

Question 9

What is a hormone?

Answer 9

A biochemical substance that circulates in the blood but only affects target organs.
-> Produced in large quantities but disappear quickly and have very powerful effects.

Question 10

What happens prenatally in the womb in regards to hormones?

Answer 10

Hormones act upon brain development and cause development of the reproductive organs.

Question 11

What happens at puberty (+ during adolescence)?

Answer 11

A burst of hormonal activity triggers the development of secondary sexual characteristics such as pubic hair.

Question 12

What is testosterone?

Answer 12

A hormone from the androgen group that is produced mainly in the male testes (and in smaller amounts in the female ovaries).
-> Hormone associated with aggressiveness.

Question 13

What happens if a genetic male produces no testosterone during foetal development?

Answer 13

No male sex organs will appear.

Question 14

What happens if a genetic female produces high levels of testosterone during foetal development?

Answer 14

Male sex organs may appear.

Question 15

What is the evolutionary explanation of high testosterone?

Answer 15

High levels of testosterone are also linked to aggression because it is adaptive.
-> Aggression towards rivals allows males to compete for the opportunity to mate with a fertile female.

Question 16

What is oestrogen?

Answer 16

The primary female hormone, playing an important role in the menstrual cycle and reproductive system.

Question 17

What is premenstrual tension (PMT)?

Answer 17

The fact oestrogen causes some women to experience heightened emotionality and irritability during their menstrual cycle.

Question 18

What is premenstrual tension (PMT) called when the effects become a diagnosed disorder?

Answer 18

Premenstrual syndrome (PMS).

Question 19

What is oxytocin?

Answer 19

A hormone which causes contraction of the uterus during labour and stimulates lactation.

Question 20

When do women produce larger amounts of oxytocin?

Answer 20

When giving birth.

Question 21

Why is oxytocin referred to as the ‘love hormone’?

Answer 21

It reduces the stress hormone cortisol and facilitates bonding.

Question 22

What does evidence suggest about the production of oxytocin?

Answer 22

Suggests that both sexes produce oxytocin in roughly equal amounts during amorous activities such as kissing and sexual intercourse.