Chapter 3 Flashcards
What are the levels at which sex is determined?
Chromosomal, gonadal, hormonal, morphological, behavioral
What is Turner Syndrome?
A condition characterized a missing X chromosome leading to slow growth in girls, requiring induced puberty with sex steroid hormones
What is Klinefelter Syndrome?
A condition with a Y chromosome but an extra X chromosome
often sterile, often associated with learning disabilities, small testes
Define ultimate causes in the context of behavior.
The evolutionary, adaptive reason for a behavior, focusing on why it evolved
What is sexual reproduction and its main advantage?
A process that promotes genetic diversity through recombination
increased adaptability to environmental changes
What are the disadvantages of asexual reproduction?
Less adaptability and increased vulnerability to pathogens
What is sexual dimorphism?
Differences in appearance and behavior between sexes
How is asexual reproduction called in animals?
parthenogenosis
How does monogamy affect sexual dimorphism?
Reduces sexual dimorphism due to the removal of selection pressure
What are proximate causes in behavior?
Immediate, mechanistic causes of a behavior, focusing on how it occurs
What are Disorders of Sex Development (DSD)?
Conditions that may result from genetic mutations, endocrine disruptions, or environmental influences
Help study and understand sex roles
What is Androgen Insensitivity Syndrome (AIS)?
A condition in males where there are non-functional androgen receptors
What is Congenital Adrenal Hyperplasia (CAH)?
genetic deficiency
that results in the overproduction of androgens by the adrenal
glands
-no reported effects on genital differentiation in males
-causes various degrees of masculinization of the external genitalia in females, which may lead to erroneous assignment of sex at
birth
What is the Organizational/Activational hypothesis?
A theory suggesting that early exposure to hormones shapes neural circuits, influencing behavior later in life
What are organizational effects of hormones?
Hormones acting early in development to shape neural circuits
- ex: testosterone exposure un utero influences brain differentiation
- prenatally or perinatally
- Hormones (especially testosterone) permanently shape the brain and body
- These changes establish sex-specific neural circuits that later respond to hormones in adulthood
What are activational effects of hormones?
Hormones later in life that trigger behaviors through previously organized circuits
- ex: testosterone promote aggressive and reproductive behaviours in males
- later in life
- act on pre-existing neural structures
If a mouse is exposed to testosterone once in adulthood, would she exhibit male-typical mounting behaviours?
No because no exposition during development so no oragnizational effects and pre-existing neural structures
What defines chromosomal sex?
The sex chromosomes inherited at fertilization
What are homogametic and heterogametic sexes?
Homogametic sex has two similar chromosomes (XX), heterogametic sex has two different chromosomes (XY)
What is gonadal sex?
presence of either ovaries or testes
What initiates testicular development in males?
The SRY gene on the Y chromosome
What happens in the absence of SRY?
Female development occurs
What are the two hormones needed for the masculinization and defminization of males?
need testis-determining factor (TDF) and Mullerian inhibiting substance (MIS) to defeminized
What need to happen to the Mullerian duct development and the Wolffian duct development to have a female-typical development?
females must be feminized (Müllerian duct development) and demasculinized (Wolffian duct regression)
