Developmental Biology

Question 1

The morula stage can be found during:

a) organogenesis
b) cleavage phase
c) gastrulation
d) fertilization

Answer 1

b) cleavage phase

Question 2

Which of the listed sequences of developmental phases or structures shows
the right temporal order:

a) zygote-blastula-morula-gastrula-neurula
b) zygote-blastula-gastrula-neurula-pheno (!! ACHTUNG: richtig ist phylo!!) typic stage
c) fertilization-cleavage-gastrulation-organogenesis
d) gastrulation-neurulation-organogenesis-cleavage

Answer 2

b) zygote-blastula-gastrula-neurula-pheno (!! ACHTUNG: richtig ist phylo!!) typic stage
c) fertilization-cleavage-gastrulation-organogenesis

Question 3

Implantation of the human embryo into the uterus occurs:

a) after compaction
b) before fertilization
c) at blastocyst stage
d) at 2-cell-stage

Answer 3

a) after compaction

c) at blastocyst stage

Question 4

What are critical events during fertilization to prevent further sperm entry:
a) acrosome reaction
b) change of oocyte membrane potential from from
negative to positive
c) release of Ca2+ from oocyte ER
d) controlled cell death

Answer 4

b) change of oocyte membrane potential from from
negative to positive

c) release of Ca2+ from oocyte ER

Question 5

What happens during gastrulation:

a) extensive cell migration
b) establishment of the three germ layers
c) neural tube closure
d) formation of the heart

Answer 5

a) extensive cell migration

b) establishment of the three germ layers

Question 6

The inner cell mass of the blastocyst gives rise to:

a) trophoblast
b) yolk sac
c) embryonic epiblast
d) amnionic ectoderm

Answer 6

b) yolk sac
c) embryonic epiblast
d) amnionic ectoderm

Question 7

A mutant that fails to form mes- endoderm during gastrulation will just consist of:

a) muscle tissue and gut
b) skin and skeleton
c) nervous system and skin
d) the germ line

Answer 7

c) nervous system and skin

d) the germ line

Question 8

Derivatives of the mesoderm are:

a) lung
b) skin
c) skeletal muscles
d) central nervous system

Answer 8

c) skeletal muscles

Question 9

Cells of the neural crest give rise to:

a) pigment cells (melanophores)
b) glial cells of the peripheral nervous system
c) facial cartilage and bone
d) adrenal cortex

Answer 9

a) pigment cells (melanophores)
b) glial cells of the peripheral nervous system
c) facial cartilage and bone

Question 10

The region specific anterior-posterior identity of the human axial skeleton is defined by:

a) specific spatio-temporal expression of a family of transcription factors with the so-called homeo-box
b) is patterned by antagonistic gradients of secreted growth factors during critical stages
c) the hox-code
d) an evolutionary highly conserved mechanism

Answer 10

a) specific spatio-temporal expression of a family of transcription factors with the so-called homeo-box
c) the hox-code
d) an evolutionary highly conserved mechanism

Question 11

Derivatives of the entoderm are:

a) pancreas
b) skin
c) liver
d) teeth

Answer 11

a) pancreas

c) liver