PSYB64 FINAL EXAM REVIEW AND
100% CORRECT ANSWERS 2025-2026
UPDATED.
X chromosome - Answer o One of two types of sex chromosomes
o Individuals with two of these are female
Y chromosome - Answer o One of two types of sex chromosomes
o Individuals with this will usually become males
Karyotypes - Answer Profile of chromosome number and appearance in the nucleus as seen
under a light microscope
Klinefelter Syndrome - Answer o Most common genetic abnormality for guys
• 1.79/1000 male births
o Features a 47/XXY genotype
o Phenotypically male, but can usually experience reduced fertility and require hormone
treatment at puberty to promote the development of secondary male sex characteristics and to
inhibit female characteristics
o Condition in males caused by an XXY genotype characterized by frequent problems with
fertility, secondary sex characteristics, and verbal skills
o Associated with normal intelligence with mild cognitive difficulties and social awkwardness
• delayed/reduced verbal skilled
• Led-handedness is more common
Turner Syndrome - Answer o Condition caused by an XO genotype characterized by frequent
abnormalities of the ovaries and infertility
Mosaic karyotype - Answer Single individual has cells with differing complements of
chromosomes
47/XYY - Answer o 1/1000 Male births
o Tend to be taller and leaner with more acne issues
o May have more aggressiveness or anti-social behaviour
o Higher risk for physical abnormalities of the eye, elbow, and chest
o IQ is slightly below the average of 46 X,Y
,o Fertile, but more likely to produce sperm with sex chromosome abnormalities
o May be more related to crime but due to confounding factors (low socioeconomic factors, less
partners, education, etc.) is still unclear
Intersex - Answer When both elements of male and female develop inside the same fetus
Testis determining factor - Answer o A protein encoded by the SRY gene on the Y
chromosome that turns the primordial gonads into testes
Wolffian system - Answer o Internal system that develops into
• Seminal vesicles
• Vas deferens
• Prostate gland
Mullerian system - Answer Internal system that develops into a uterus, fallopian tube, and
the upper two thirds of the vagina in the absense of anti-mullerian hormone
Anti-mullerian hormones - Answer o Hormone secreted by fetal testes that causes
degeneration of mullerian system
Androgen insensitivity syndrome - Answer A condition in which a genetic male fetus lacks
functional androgen receptors which leads to the development of female external genitalia and
typically female gender identity and sexual behaviour
• 5-Alpha-dihydrotestosterone - Answer o Androgen secreted by the testes that masculinizes
the external genitalia
o Must be recognized by receptor sites for male external genitals to form normally
o Made by testosterone and enzyme 5-alpha-reductase
Congenital adrenal hyperplasia (CAH) - Answer Condition where fetus is exposed to higher
than normal androgens resulting in masculinization of external genitalia and cognitive behaviors
in affected females
Secondary sex characteristics - Answer Characteristics related to sex that appear at puberty,
including deepening voice, and facial hair growth in males, and widening hips, breast
development in females
Sexual orientation - Answer Stable pattern of attraction to members of a particular sex
,Cognitive reversal - Answer Homosexual individuals perform like their opposite sex
o Not a gender inversion though, proven by the self identification scale of Masculinity/feminity
Ovum - Answer A female reproductive cell or egg
Ovulation - Answer Process of releasing a mature egg from the ovary
Follicle - Answer One of the clusters of cells in the ovary, each of which contains an egg cell
Progesterone - Answer Promotes pregnancy (gestation) by preventing the development of
additional follicles and by further developing the lining of the uterus
Which step is necessary for turning testosterone into estradiol? - Answer Aromatization
Estrogen levels in women can predict a variety of cognitive and behavioural abilities. Which of
the following is NOT characteristic of high levels of estrogen? - Answer Increased sexual
behaviour
During the onset of puberty, the hypothalamus releases gonadotropin releasing hormone
(GnRH), which causes the anterior pituitary to develop hormones. Which hormone is stimulated
by GnRH? - Answer Luteinizing hormone
Follicle stimulating hormone
What can the 2D:4D ratio measure? - Answer to measure the relative amount of
testosterone relative to estrogen exposed prenatally. The 2D refers to the length second digit
(i.e., the index finger), while the 4D refers to the fourth digit (i.e., the ring finger).
Generally speaking, both androgen and estrogen receptors are present on the second and
fourth digits. However, there are more androgen receptors on the fourth digit. Thus, having a
smaller 2D:4D ratio would mean that an individual would have more testosterone relative to
estrogen. This is why males are thought to have a smaller 2D:4D ratio relative to females (who
have near equivalent lengths in their ring and index finger), due to the excess in androgens.
Which of the genetic sex disorders result in the acquisition of an extra chromosome? - Answer
Klinefelter Syndrome
, XYY Male
Androgen insensitivity syndrome (AIS) is a condition that affects males during prenatal
development. As the name suggests, it renders the body unable to respond to androgens,
resulting in an undeveloped Wolffian system. What is most likely to happen to an adult male
who was born with this syndrome? - Answer he is infertile
his physical appearance is similar to a female
Anti-Mullerian hormone still works normally, so the female Mullerian system fails to develop.
Although assessments of physical attractiveness vary amongst nearly everyone, researchers
have managed to narrow down some key features that may enhance attractiveness in a mate.
One of these features is an individual's scent. Why might this be the case? - Answer Scents
indicate immune system differences
Sex-determining region of the Y chromosome (SRY) - Answer o A gene located on the short
arm of the Y chromosome that encodes for testis-determining factor
o Expressed at 6 weeks in male embryos
What is true of the hormone melatonin? - Answer release is stimulated by light absense
Gonadotropin releasing hormone (GaRH) - Answer o Released by the hypothalamus
o Initiates the release of two hormones by the anterior pituitary gland that trigger the
production of sex hormones in the gonads by the anterior pituitary glands
EEG recordings of the brain during REM sleep reveal a characteristic waveform associated with
eye movements, namely, PGO waves. They originate in the pons before travelling elsewhere in
the brain. In which brain structures listed below does this waveform travel to? - Answer
Occipital Lobe
Lateral geniculate nucleus
List three major differences between nightmares and night terrors. - Answer Sleep terrors
- within four hours of bedtime
- disoriented confused when awoken
- unaware of caregiver presence and not consolable
- no memory of events unless fully awakened
- Partial arousal from deep NREM sleep
100% CORRECT ANSWERS 2025-2026
UPDATED.
X chromosome - Answer o One of two types of sex chromosomes
o Individuals with two of these are female
Y chromosome - Answer o One of two types of sex chromosomes
o Individuals with this will usually become males
Karyotypes - Answer Profile of chromosome number and appearance in the nucleus as seen
under a light microscope
Klinefelter Syndrome - Answer o Most common genetic abnormality for guys
• 1.79/1000 male births
o Features a 47/XXY genotype
o Phenotypically male, but can usually experience reduced fertility and require hormone
treatment at puberty to promote the development of secondary male sex characteristics and to
inhibit female characteristics
o Condition in males caused by an XXY genotype characterized by frequent problems with
fertility, secondary sex characteristics, and verbal skills
o Associated with normal intelligence with mild cognitive difficulties and social awkwardness
• delayed/reduced verbal skilled
• Led-handedness is more common
Turner Syndrome - Answer o Condition caused by an XO genotype characterized by frequent
abnormalities of the ovaries and infertility
Mosaic karyotype - Answer Single individual has cells with differing complements of
chromosomes
47/XYY - Answer o 1/1000 Male births
o Tend to be taller and leaner with more acne issues
o May have more aggressiveness or anti-social behaviour
o Higher risk for physical abnormalities of the eye, elbow, and chest
o IQ is slightly below the average of 46 X,Y
,o Fertile, but more likely to produce sperm with sex chromosome abnormalities
o May be more related to crime but due to confounding factors (low socioeconomic factors, less
partners, education, etc.) is still unclear
Intersex - Answer When both elements of male and female develop inside the same fetus
Testis determining factor - Answer o A protein encoded by the SRY gene on the Y
chromosome that turns the primordial gonads into testes
Wolffian system - Answer o Internal system that develops into
• Seminal vesicles
• Vas deferens
• Prostate gland
Mullerian system - Answer Internal system that develops into a uterus, fallopian tube, and
the upper two thirds of the vagina in the absense of anti-mullerian hormone
Anti-mullerian hormones - Answer o Hormone secreted by fetal testes that causes
degeneration of mullerian system
Androgen insensitivity syndrome - Answer A condition in which a genetic male fetus lacks
functional androgen receptors which leads to the development of female external genitalia and
typically female gender identity and sexual behaviour
• 5-Alpha-dihydrotestosterone - Answer o Androgen secreted by the testes that masculinizes
the external genitalia
o Must be recognized by receptor sites for male external genitals to form normally
o Made by testosterone and enzyme 5-alpha-reductase
Congenital adrenal hyperplasia (CAH) - Answer Condition where fetus is exposed to higher
than normal androgens resulting in masculinization of external genitalia and cognitive behaviors
in affected females
Secondary sex characteristics - Answer Characteristics related to sex that appear at puberty,
including deepening voice, and facial hair growth in males, and widening hips, breast
development in females
Sexual orientation - Answer Stable pattern of attraction to members of a particular sex
,Cognitive reversal - Answer Homosexual individuals perform like their opposite sex
o Not a gender inversion though, proven by the self identification scale of Masculinity/feminity
Ovum - Answer A female reproductive cell or egg
Ovulation - Answer Process of releasing a mature egg from the ovary
Follicle - Answer One of the clusters of cells in the ovary, each of which contains an egg cell
Progesterone - Answer Promotes pregnancy (gestation) by preventing the development of
additional follicles and by further developing the lining of the uterus
Which step is necessary for turning testosterone into estradiol? - Answer Aromatization
Estrogen levels in women can predict a variety of cognitive and behavioural abilities. Which of
the following is NOT characteristic of high levels of estrogen? - Answer Increased sexual
behaviour
During the onset of puberty, the hypothalamus releases gonadotropin releasing hormone
(GnRH), which causes the anterior pituitary to develop hormones. Which hormone is stimulated
by GnRH? - Answer Luteinizing hormone
Follicle stimulating hormone
What can the 2D:4D ratio measure? - Answer to measure the relative amount of
testosterone relative to estrogen exposed prenatally. The 2D refers to the length second digit
(i.e., the index finger), while the 4D refers to the fourth digit (i.e., the ring finger).
Generally speaking, both androgen and estrogen receptors are present on the second and
fourth digits. However, there are more androgen receptors on the fourth digit. Thus, having a
smaller 2D:4D ratio would mean that an individual would have more testosterone relative to
estrogen. This is why males are thought to have a smaller 2D:4D ratio relative to females (who
have near equivalent lengths in their ring and index finger), due to the excess in androgens.
Which of the genetic sex disorders result in the acquisition of an extra chromosome? - Answer
Klinefelter Syndrome
, XYY Male
Androgen insensitivity syndrome (AIS) is a condition that affects males during prenatal
development. As the name suggests, it renders the body unable to respond to androgens,
resulting in an undeveloped Wolffian system. What is most likely to happen to an adult male
who was born with this syndrome? - Answer he is infertile
his physical appearance is similar to a female
Anti-Mullerian hormone still works normally, so the female Mullerian system fails to develop.
Although assessments of physical attractiveness vary amongst nearly everyone, researchers
have managed to narrow down some key features that may enhance attractiveness in a mate.
One of these features is an individual's scent. Why might this be the case? - Answer Scents
indicate immune system differences
Sex-determining region of the Y chromosome (SRY) - Answer o A gene located on the short
arm of the Y chromosome that encodes for testis-determining factor
o Expressed at 6 weeks in male embryos
What is true of the hormone melatonin? - Answer release is stimulated by light absense
Gonadotropin releasing hormone (GaRH) - Answer o Released by the hypothalamus
o Initiates the release of two hormones by the anterior pituitary gland that trigger the
production of sex hormones in the gonads by the anterior pituitary glands
EEG recordings of the brain during REM sleep reveal a characteristic waveform associated with
eye movements, namely, PGO waves. They originate in the pons before travelling elsewhere in
the brain. In which brain structures listed below does this waveform travel to? - Answer
Occipital Lobe
Lateral geniculate nucleus
List three major differences between nightmares and night terrors. - Answer Sleep terrors
- within four hours of bedtime
- disoriented confused when awoken
- unaware of caregiver presence and not consolable
- no memory of events unless fully awakened
- Partial arousal from deep NREM sleep
