ANSC 3040 MIDTERM QUESTIONS AND CORRECT
ANSWERS
What is a hormone? - Answers - signaling molecules that modulate the activity of a
target tissue
List and describe 5 types of endocrine signaling - Answers - 1) Classical endocrine
signaling: Hormone is secreted by an endocrine cell, enters the blood steam and binds
to receptors in target tissue
2) Neuroendocrine: Hormone is released from a neuroendocrine cell into the blood and
transported to target tissue
3) Autocrine: The cell secreting the hormone is the target cell
4) Paracrine: Hormone is released and diffuses through interstitial tissue to a near by
target cell
5) Neurocrine: A nerroendocrine cell secretes a hormone in close proximity to the target
cell
What are the 3 ways to classify reproductive hormones? - Answers - Source
Mode of action
Biochemical
What are the 5 steps in hormone activity? - Answers - Synthesis
Secretion
Transport to target tissue
Receptor binding in target tissue
Clearance
What is the HPG axis? - Answers - hypothalamic-pituitary-gonadal axis
When is gender determined? - Answers - At fertilization (day 1)
What controls gender and how? - Answers - X and Y chromosomes
(XX=female, XY=male)
The XY pair in males will be separated during spermatogenesis
Females will always produce gametes containing an X chromosome
Germ cells and somatic are (diploid/haploid) and gametes are (diploid/haploid) -
Answers - Diploid (2n)
Haploid (1n)
When is the first round of differentiation and what do the cells differentiate into? -
Answers - 16 cells
Inner cell mass and trophectoderm
, What does totipotent mean? - Answers - Cells capable of differentiation into any type of
embryonic (body) or extra-embryonic cells (placental)
_____________are multipotent cells and differentiate into what? - Answers -
Trophectoderm
Placental cells
What does multipotent mean? - Answers - Cells that are capable of differentiating into
any type of cells within a cell lineage(i.e. placental cells)
___ is pluripotent and differentiate into what? - Answers - ICM (inner cell mass)
Any type of cells in the embryo (i.e. endoderm, mesoderm and ectoderm)
What is epigenetics? - Answers - Genetic markers that regulate gene expression (i.e.
methylation and histones)
When does gastrulation occur? - Answers - Early embryogenesis
What cells differentiate into the epiblast? - Answers - ICM cells that are in contact with
the blastocoele
What do the cells released from the primitive streak become? - Answers - Mesoderm
What does the endoderm differentiate into? - Answers - Digestive system
Lungs
Endocrine system
What does the mesoderm differentiate into? - Answers - Muscle
Skeleton
Cardiovascular system
Internal reproductive tract
Urinary system
What does the ectoderm differentiate into? - Answers - Nervous system
Skin
Hair
External reproductive tract
What region does the reproductive and urinary systems develop? - Answers - Somitic
mesoderm
What region will the gonads from? - Answers - The gonadal ridge (primordial gonads)
What are PGCs? - Answers - Primordial germ cells
ANSWERS
What is a hormone? - Answers - signaling molecules that modulate the activity of a
target tissue
List and describe 5 types of endocrine signaling - Answers - 1) Classical endocrine
signaling: Hormone is secreted by an endocrine cell, enters the blood steam and binds
to receptors in target tissue
2) Neuroendocrine: Hormone is released from a neuroendocrine cell into the blood and
transported to target tissue
3) Autocrine: The cell secreting the hormone is the target cell
4) Paracrine: Hormone is released and diffuses through interstitial tissue to a near by
target cell
5) Neurocrine: A nerroendocrine cell secretes a hormone in close proximity to the target
cell
What are the 3 ways to classify reproductive hormones? - Answers - Source
Mode of action
Biochemical
What are the 5 steps in hormone activity? - Answers - Synthesis
Secretion
Transport to target tissue
Receptor binding in target tissue
Clearance
What is the HPG axis? - Answers - hypothalamic-pituitary-gonadal axis
When is gender determined? - Answers - At fertilization (day 1)
What controls gender and how? - Answers - X and Y chromosomes
(XX=female, XY=male)
The XY pair in males will be separated during spermatogenesis
Females will always produce gametes containing an X chromosome
Germ cells and somatic are (diploid/haploid) and gametes are (diploid/haploid) -
Answers - Diploid (2n)
Haploid (1n)
When is the first round of differentiation and what do the cells differentiate into? -
Answers - 16 cells
Inner cell mass and trophectoderm
, What does totipotent mean? - Answers - Cells capable of differentiation into any type of
embryonic (body) or extra-embryonic cells (placental)
_____________are multipotent cells and differentiate into what? - Answers -
Trophectoderm
Placental cells
What does multipotent mean? - Answers - Cells that are capable of differentiating into
any type of cells within a cell lineage(i.e. placental cells)
___ is pluripotent and differentiate into what? - Answers - ICM (inner cell mass)
Any type of cells in the embryo (i.e. endoderm, mesoderm and ectoderm)
What is epigenetics? - Answers - Genetic markers that regulate gene expression (i.e.
methylation and histones)
When does gastrulation occur? - Answers - Early embryogenesis
What cells differentiate into the epiblast? - Answers - ICM cells that are in contact with
the blastocoele
What do the cells released from the primitive streak become? - Answers - Mesoderm
What does the endoderm differentiate into? - Answers - Digestive system
Lungs
Endocrine system
What does the mesoderm differentiate into? - Answers - Muscle
Skeleton
Cardiovascular system
Internal reproductive tract
Urinary system
What does the ectoderm differentiate into? - Answers - Nervous system
Skin
Hair
External reproductive tract
What region does the reproductive and urinary systems develop? - Answers - Somitic
mesoderm
What region will the gonads from? - Answers - The gonadal ridge (primordial gonads)
What are PGCs? - Answers - Primordial germ cells
