Sexual Reproduction Quiz

When genetic sex is determined

At birth

Genetic makeup of sperm

X or Y

Y chromosome

Chromosome that codes for sex

Genetic makeup of Ova

X

SRY gene

Sex determining region on Y chromosome

SRY gene code

Testes determining factor that releases a protein that influences gonadal development

SRY translocation

Testes develop still

Absence of SRY signal

Female gonadal development occurs

Genetic sex

Determines what gonads develop

Presence of SRY gene

Testes develop

Development of internal sex organs

Hormones secreted by gonads determine

Mullerian system

Precursor to the internal female sex organs

Requirement of mullerian system

No additional hormones are needed

Wolffian system

Precursor to male internal sex organs

Requirement of wolffian system

Needs hormones to develop

Genetic composition of Turner syndrome

XO

Effects of Turner Syndrome

Not fully developed ovaries due to missing X, normal internal sex organs, normal external genitalia, cannot bear children

Testes secrete

Anti-mullerian hormones and androgens

Anti mullerian hormones

Inhibit development of female internal organs - defeminizing effect

Androgens

Stimulate development of Wolffian system - Masculinizing effect

Types of androgens

Testosterone and dihydrotestosterone

AIS genetic makeup

XY with dysfunction androgen receptor

Cause of AIS

No androgen receptor inhibits Wolffian development, no development of male external genitalia

Effects of AIS

Mullerian system is suppressed, but female external organs still develop giving a female appearance

Genetic makeup of Mullerian Duct Syndrome

XY disorder

Effects of PMDS

aMH receptors or genes are dysfunctional and female organs interfere with function of male organs

Organizational effects

Effect of hormones prenatally on sex organs and brain development

Primary sex characteristics are

Influenced by Organizational effects

Activational effects

The effect hormones have during puberty

Secondary sex characteristics are

Influenced by activational effects, but depends on organizational effects

Primary sex characteristics

Gonads, internal sex organs, and external genitalia

Testes secrete

Testosterone - Wolffian, anti mullerian hormones, dihydrotestosterone - External

Lack of testes

No androgens are secreted, mullerian system develops and external female genitals develop

Secondary sex characteristics

Emerge at puberty, male: grow bears, axillary hair, voice drop; female:Re-distribution of fat, breasts develop, menstrual cycle begins

Hypothalamus

Secretes Gonadotropin releasing hormones (GnRH)

Anterior pituitary gland

Responds to GnRH by releasing gonadotropic hormones

Gonadotropic hormones

Follicle stimulating hormone (FSH) and Leutenizing hormone (LH)

Gonads

Respond to GH’s by releasing their own hormones

Hormones

Effect their target tissues and organs producing secondary sex characteristics

Effect of testosterone

Production of sperm, facial hair, pubic and axillary hair, voice deepens, and increased sex drive

Effects of estradioal

Maturation of female genitals, breasts, fat deposits, growth of uterine lining

Kisspeptin

Protein produced in Arcuate Nucelus that modulates GnRH release

Function of Kisspeptin

Essential for initiation of puberty and maintenance of male and female reproductive ability

Genetic makeup of Klienfelter’s Syndrome

XXY

Effect of Klienfelter’s syndrome

Testes and male genitals develop but XX combination impedes male development, reduces testes and genitals

Genetic makeup of Jacob’s syndrome

XYY

Mammalian female reproductive cycle

Estrus cycle

Estrus cycle

Hormonal states regulate reproductive behaviors

Primate female reproductive cycle

Menstrual cycle

Menstrual cycle

Hormones regulate fertility, but not mating behaviors, can engage in mating behaviors anytime

Ovarian follicles

Stimulated by the release of FSH, cluster of cells surrounding ovum

Mature ovarian follicles

Secrete estradiol which induces uterine lining growth for implantation of egg

Leutenizing hormone

Induces ovulation after ovarian follicle ruptures releasing ovum to fallopian tube

Corpus luteum

Left behind ovarian follicle cells

Corpus luteum secretes

Estradiol and progesterone

Estradiol

Primary female hormone

Progesterone

Important for maintaining lining of uterus, inhibit release of FSH and LH

Hormonal influence on behaviors

Females are more likely to initiate during ovulatory phase

Male hormonal regulation

LH stimulates testosterone production, FSH maintains sperm production

Low testosterone

Reduced sperm production and interest in sexual behaviors