Embryogenesis

Question 0

Genotypic sex in mammals

Answer 0

Male: XX
Female: XY
Determined at fertilization

Question 1

Definition of sex

Answer 1

The sum total of morphological, physiological and psychological differences that distinguish a male from a female

Question 2

Genotypic sex in avian species

Answer 2

Male: ZZ
Female: ZW
Determined at ovulation

Question 3

Sex determination

Answer 3

Result of genotypic sex and sex differentiation or the development in the male or female direction

Question 4

Primary sex ratio

Answer 4

At fertilization

Question 5

Secondary sex ratio

Answer 5

At parturition/birth

Question 6

Tertiary sex ratio

Answer 6

At puberty

Question 7

Three germ layers

Answer 7

Endoderm, mesoderm and ectoderm

Question 8

Endoderm

Answer 8

Digestive system, lungs, endocrine system

Question 9

Mesoderm

Answer 9

Muscle, skeleton, cardiovascular, reproductive system (uterus, cervix, part of vagina, epididymis, ductus deferens, accessory sex glands)

Question 10

Ectoderm

Answer 10

Nervous system, skin, hair, mammary glands, hypothalamus and both loves of the pituitary gland, portions of the vagina, the penis and clitoris

Question 11

Origination of the posterior pituitary gland

Answer 11

Neural tissue of the brain

Question 12

Origination of the anterior pituitary gland

Answer 12

Stromodeal ectoderm from the roof of the mouth; diverticulum from roof of mouth is Rathke’s pouch and eventually forms anterior pituitary

Question 13

Hypophysis

Answer 13

Pituitary gland

Question 14

Adenohypophysis

Answer 14

Anterior lobe

Question 15

Neurohypophysis

Answer 15

Posterior lobe

Question 16

Spenoid bone

Answer 16

Begins to surround the p. gland as it nears completion forming a protective cavity termed the sella turcica

Question 17

Early embryo sexual differentiation

Answer 17

Primordial germ cells develop

Question 18

Primordial germ cells

Answer 18

Originate in the yolk sac and migrate to and reside on the undifferentiated gonad

Question 19

Gonadal ridge/genital ridge

Answer 19

Undifferentiated gonad

Question 20

Three morphologically distinct renal systems

Answer 20

Pronephros, mesonephros, metanephros

Question 21

Pronephros

Answer 21

Non-functional remnant of a primitive form of kidney found in lower animals, regresses

Question 22

Mesonephros

Answer 22

Functional, bilateral pair of intermediate kidneys which produce urine which is drained by mesonephric ducts

Question 23

Metanephros

Answer 23

Will develop functional nephrons and will serve as the kidneys of the newborn animal

Question 24

Paramesonephric ducts

Answer 24

Müllerian ducts, form adjacent to the mesonephros and associated mesonephric ducts

Question 25

TDF

Answer 25

Testis determining factor, single substance that regulates sexual differentiation, present on the Y chromosome

Question 26

Mesonephric tubules in males

Answer 26

Give rise to the efferent duct system; rete testis duct system and efferent ducts of the testis

Question 27

Mesonephric ducts in males

Answer 27

Give rise to the epididymis and the ductus deferens

Question 28

Paramesonephric ducts in females

Answer 28

Gives rise to the oviducts, uterus, cervix and cranial vagina

Question 29

Testicular descent

Answer 29

Requires rapid growth followed by significant shrinkage of the gubernaculum

Question 30

Freemartinism

Answer 30

Occurs when twins, male and female, share a common blood supply in utero. Male calf secretes TDF and AMH before female development pathway, female will be sterile with male behavior

Question 31

Kallman's Syndrome

Answer 31

X-chromosome related. Lack of GnRH leads to no LH and FSH. Hypogonadotropin eunuchoidism, hypogonadism. Abnormal development of GnRH neurons in hypothalamus

Question 32

Turner's syndrome

Answer 32

Females. Lacking one sex chromosome. 1/2500 live births, anatomically hermaphrodite, sterile, can treat symptoms with steroids

Question 33

Klinefelter's syndrome

Answer 33

Males, XXY, 1/1000, enlarged breasts, rounded body type, sparse facial and body hair, small testes, inability to produce sperm

Question 34

Testicular feminization

Answer 34

Normal XY males with lack of androgen receptors