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WorksheetsEvoDevo
Total questions: 83
Worksheet time: 21hrs 45mins
Wat is het verschil tussen embryonale stamcellen en volwassen stamcellen?
Een embryonale stamcel is pluripotent, een volwassen stamcel is unipotent
Een volwassen stamcel is pluripotent, een embryonale stamcel is totipotent
beiden zijn pluripotent
Een embryonale stamcel is pluripotent, een volwassen stamcel is multipotent
De anterior-posterior as is al gespecificeerd voor de bevruchting in:
xenopus (kikker)
muis
drosophila
zebravis
Welke van de volgende beschrijvingen is onjuist?
Genomic imprinting in zoogdieren betekent dat bepaalde genen slechts door een allel uitgedrukt worden, afhankelijk van het geslacht van de ouder van oorsprong
imprinted genen worden vaak gevonden in clusters van genen, waarvan er velen imprinted zijn
Om genomic imprinting te laten plaatsvinden, moeten er twee kopieën van hetzelfde chromosoom overgeërfd worden van een ouder in een diploïde cel
Binnen een imprinted gen cluster worden genen op een van de twee ouderlijke chromosomen stilgelegd, maar de equivalente genen op het andere ouderlijke chromosoom niet
Welke categorie patterning genen codeert de leden van bekende intercellulaire signalling pathways?
Pair-rule genen
segmentatie polariteitsgenen
Gap genen
hox genen
Wat zijn corticale korrels/granules?
Cellen die de oocyt omringen in het preovulaire follikel
cellen die het oocyt omringen na ovulatie
Blaasjes (vesicles) gevuld met enzym in het oocyt
blaasjes gevuld met enzym in zaadcellen
Niet lang nadat het menselijke genoom ontleed was werden verschillende interessante kenmerken blootgelegd, waaronder het bestaan van haplotype blokken. Omtrent meiose, wat is de betekenis van de ontdekking van haplotype blokken?
cross-over breekpunten kunnen overal in het genoom plaatsvinden
homologe recombinatie is niet beperkt tot specifieke gebieden in het genoom
SNPs binnen haplotype blokken co-segregeren tijdens meiose
genetische studies zullen gecompliceerder zijn dan wat daarvoor was verwacht
Tijdens drosophila gastrulatie verplaatst mesoderm zich door het
primitives streak
node
dorsal lip
ventral furrow
If expression of all copies of a particular Hox gene were knocked out, what would the expected result be regarding the identity of the affected region?
The region would take on the identity of the next anterior region to it
The region would take on the identity of the next posterior region to it.
The region would revert to a default identity (i.e. would not differentiate into any structure).
The region would take on an intermediate identity between that of the anterior and posterior region to it.
What does the “clock and wavefront” model propose?
Cells must be passed by the wavefront to commit to forming a somite
Oscillatory expression of Fgf and RA provide information to the cells to form somites
Cells must not have yet passed the wavefront to commit to forming a somite
Genes that position a wavefront have clock-like gene expression.
PGC specification in some organisms relies on
the intrinsic germ plasm components
silencing of the sex chromosomes after fertilisation.
a counter-intuitive activation of somatic genes.
signalling within the gonads during embryonic development.
Which of the following statements is false? During development of Drosophila eggs, the nurse cells
Contribute mRNA to the egg
Are joined to the egg by cytoplasmic bridges
donate cytoplasm to the egg
provide the anterior-posterior signals of the egg
Which of the following statements is false?
The pattern of X-chromosome inactivation in the epiblast occurs in a random fashion but once it has been established it is propagated to the same X (paternal or maternal) through all subsequent mitotic cell divisions.
In X-chromosome inactivation, the inactivated X chromosome is epigenetically silenced by a protein, called Xist, that is produced from the inactive-to-be X chromosome.
The inactivated X chromosome carries the types of histone modification that are typical of heterochromatin.
Xist works by coating most of the X chromosome that is to be inactivated and then recruiting Polycomb proteins to condense the chromosome.
Which one is false of the drosophila dorsal protein?
control regions target genes differ in their affinity for the dorsal protein
the ventral region of the drosophila embryo expresses genes that are repressed by the dorsal protein
the gradient of dorsal protein divides the drosophila embryo into well defined domains
dorsal protein levels are mostly nuclear within the dorsal region of the drosophila embryo
During early development of the mammalian species both the Mullerian and Wolffian ducts are formed and present in male and female embryo’s. A little later the Wolffian ducts will remain in males, whereas the Mullerian ducts remain in females. Which of the following statements with respect to the action of different sex hormones is correct?
Testosterone is required for regression of the mullerian ducts
testosterone is required for maintaining the wolffian ducts
AMH is required for maintainance of the mullerian ducts
AMH is required for regression of the wolffian ducts
What is the result of the first twelve nuclear divsisions of a drosophila embryo where roughly 6000 nuclei share a single cytoplasm?
micropile
pole cell
syncytium
cellular blastoderm
What class of patterning genes encode members of known intercellular signalling pathways?
pair rule genes
segmentation genes
hox genes
gap genes
What is defined as the similarity between embryonic hox gene expression and the order of hox genes along a chromosome?
segment polarity
homeosis
gene cluster
co linearity
Which of these segmentation genes is a transcription factor that defines parasegment boundaries?
frizzled
hedgehog
patched
engrailed
Which of the following is not true of drosophila germ-line development?
germ line development begins in the anterior region of the egg
germ cells are derived from pole cells
shifting the position of pole plasm shifts the position of germ cell specification
germ cells are specified by inheriting cytoplasmic determinants
How many distinct germplasm regions are present in a zebrafish embryo?
1
2
3
4
Which of the following animals generates germ cells by pre-formation?
drosophila, c. elegans and chicken
c. elegans, drosophila and mouse
mouse, chicken and c. elegans
chicken, drosophila and mouse
Which of the following biological processes is not required for multicellularity?
cell to cell communication
cell death
cell adhesion
sexual reproduction
Which of the following processes is critical for dorsal-ventral axis specification in c. elegans?
cell to cell communication
sperm entry point
asymmetric cell division
induction by the mother
imprinted genes
provide an example of epigenetic inheritance
are located near differentially methylated regions
are only transmitted by one parent
a and b
none of the above
genomic imprinting
activates genes
involves dna methylation
is only found in mammals
inactivates one of the sex chromosomes
is always maternally inherited
which of these would be an example of a homeotic phenotype?
the wings are shrunken and useless
the eyes of the fly are brown instead of normal red
the first abdominal segment has legs
all of these
none of these
in drosophila development, an embryonic parasegment
is the same structure as a segment
will contribute to two different segments in the adult fly
is retained as a structure in the adult fly
is not defined by gene expression
develops at the syncytial stage
activation of hunchback by bicoid demonstrates which of the following concepts?
cell to cell communication
homeotic mutation
critical threshold concentration
segmentation
none of these
which of these would not be an example of positional information?
a specific cell in the embryo known that it need to divide into daughter cells
cells at the anterior end of the embryo develop into structures of the head
cell that form the germline migrate from their initial position to colonize the gonads
the dorsal-ventral axis in c elegans is determined by cell to cell interactions
all of the above are examples of positional information
which is true for primordial germ cells (pgc's)?
they follow extracellular signals
they give rise to mesoderm
they have an internal program that allows them to migrate
A and C
B and C
In insects, like drosophila, the action of ... genes determines the initial course of development
zygote
larval
paternal
imaginal
maternal
Volvox and chlamydomonas are used as model systems to study multicellular development because
both are unicellular and are closely related to multicellular algae
volvox has two different cell types, one of which remarkably resembles chlamydomonas, which is unicellular
their mating loci have the same number of genes but still, volvox is a sexual organism and chlamydomonas is asexual
they can switsch between haploid and diploid life cycles depending on the environmental conditions
Dictyostelium discoideum is a unicellular amoeba. However, it can aggregate to form a multicellular-like entity called a ‘slug’ in case of food/bacteria scarcity. Choose the correct statement:
It is unclear what means of communication these amoebae use to aggregate
because of this aggregation of different amoebae, there can be genetic competition, unlike in a true multi-cellular organism where all cells are genetically identical
the slug will eventually become a stalk and a spore sack, both of which can survive by traveling to other locations through wind, water, animal transport, ect.
physical interaction is the means by which single amoebae come together to form the slug
The first family of genes that is zygotically activated and is expressed during the entire lifetime of drosophila is
the gap genes family
the maternal effect gene family
the segmentation gene family
the pair rule gene family
Removing the ventral blastomeres from a four-cell amphibian embryo gives rise to an embryo lacking which tissue?
notochord
neural tube
somites
gut
Which structure is essential for the connection between homologous chromosomes at the metaphase of the first meiotic division?
the kinetochore
the centrosome
the synaptonemal complex
the sister chromatid cohesion complex
To facilitate proper development of the embryo, epigenetic information needs to be reset. at what time point and how often during development of mammalian species does this happen?
once, during gametogenesis
twice, during germ cell development and just after implantation
twice, just after fertilisation and during germ cell development
once, just after implantation
the amphibian egg is radially symmetric along the animal-vegetal axis. what 'breaks' this symmetry?
localization of maternal RNA's to the vegetal pole
fertilization
localization of maternal RNA's to the animal pole
cleavage
Which of the wollowing statements is false about the role of wnt/b-catenin pathway in dorso-ventral patterning?
wnt mRNA molecules concentrate on the animal side of the embryo, opposite to the sperm entry point
introduction of a dominant-negative wnt receptor ventralizes the embryo
b-catenin stabilization results in gene activation
over-expression of b-catenin dorsalises the embryo
What kind of trade-off mechanism is thought to have driven anisogamy?
germ cell size/energy source
germ cell size/germ cell number
germ cell mobility/germ cell number
energy source/germ cell number
what do we call a group of cells that differentiates according to its normal fate even after it has been isolated from the embryo and cultures in a neutral environment?
specified
determined
chimeric
competent
epigenesis and preformation are two early theories on how embryo formation occurs. which of the following is a correct description of the concept of epigenesis?
epigenetic changes mediate embryo formation
new structures arise progressively as the embryo forms
all essential parts of animal are present from the very beginning
embryo development relies on specific temperature and wetness aspects
homologous genes can be either paralogs or orthologs. which mechanism contributes to the formation of orthologs?
gene duplication
horizontal gene transfer
speciation
dna segment shuffling
Which developmental process establishes a coordinate system whereby cells 'know' their location within an embryo?
morphogenesis
cell differentiation
pattern formation
growth
Which of the descriptions below fits the concept of the “interhomolog bias”?
DSBs are not induced on the same place on the two homologous chromosome
. DSBs are non-randomly distributed in the genome.
Repair of meiotic DSBs occurs preferentially with use of intact sequence from the homologous chromosome
Repair of meiotic DSBs occurs preferentially with the use of homologous recombination
Choanoflagellates are a very interesting organism used to study the evolution of multicellular organisms from single cell organisms because:
they are multicellular and the evolutionary closest living relative to all animals
they can cluster in colonial multicellular organisms, a likely step that might have happened before the formation of a true multicellular organism.
they are very similar to the cells that Volvox has in its structure
. they are capable of cell differentiation into two cell types, the stalk cells and the spore cells, the latter being the only type to survive.
During the first cleavage divisions in mammals, the embryonic genome is gradually activated, while stored maternal mRNA and protein ensure a supply of essential proteins that are required to survive the initial, transcriptionally inactive period. In zebrafish, the transcription factors Pou5f3, Sox19b, and Nanog have been described to “open up chromatin” during this phase. What could directly mediate “opening up chromatin”?
Methylation of DNA
transcription factor phosphorylation
histone remodeling
nuclear pore activation
Which of the cell types listed below will be lost in a frizzled knockout C. elegans early embryo?
aba
abp
p2
ems
none of the above
the use of segments as a developmental strategy in vertebrates is evident in:
the endoderm
the axial skeleton, only
the hindbrain, only
both the axial skeleton and the hindbrain
the ventral epidermis
The impact of the meteorite that hit the earth 66 million years ago was immense. It appears that pieces of the earth shed off during the impact even landed on the moon. In the aftermath of this impact, huge fires destroyed most of the life on earth, and it is thought that only a few mammals survived this disaster. Marsupials are found both in Australia, South America and even North America. What is the most plausible explanation for the distribution of marsupials?
Multiple marsupial species survived the inferno on different continents.
One species survived and spread from there to other continents.
Marsupials spread from Australia to the Americas over water.
Convergent evolution from one common ancestor.
Which of following statements about C. elegans is false?
They consist of 959 somatic cells
Their genome encodes 10 times less genes than the human genome
The complete cell lineage is known.
The cell lineage is invariant.
In some model organisms, meiotic double strand breaks (DSBs) are induced before homologous chromosome pairing, and in other model organisms they are induced after homologous chromosome pairing. However, in male Drosophila meiosis, DSBs are not formed at all! What does this imply?
This species must have a different chromosome pairing mechanism compared to organisms that induce DSBs after chromosome pairing
This species must have lost the SPO11 enzyme from its genome in recent evolution.
Crossovers are not formed in male drosophila meiosis.
Cohesin complexes are non-functional in male drosophila meiosis
What is the ploidy and DNA content of the male pronucleus in mammals immediately after it has been formed?
1n, 1c
2n, 1c
1n, 2c
2n, 2c
which family of genes gives identity to segments in drosophila?
pair rule genes
segmentation genes
selector genes
gap genes
during gastrulation in chicken,
the neural plate closes to form the neural tube
there is mesenchymal-to-epithelial transition of cells
there is ingression of mesodermal cells
the somites are all formed at the same time following the 'clock and wavefront' model
what happens to a drosophila embryo if dorsal is knocked out?
the embryo becomes dorsalised
nothing, the embryo develops normally
the embryo becomes ventralised
the embryo's anterio-posterior axis is disturbed
Which of the following processes represents an example of pattern formation?
compaction
gastrulation
oogenesis
epithelial-to-mesenchyme transition
In drosophila, pair-rule genes regulate gap genes because:
they can bind to the gap gene regulatory regions to exert their function
they are morphogens and diffuse between cells
actually, pair rule genes do not regulate gap genes, it's the other way around
actually, they can't regulate each other because they are expressed at different developmental periods
Hundred fifty million years ago the mammalian X and Y chromosomes were one and the same set of autosomes. However, as a consequence of a few mutations that transformed Sox3 into Sry the Y started to degenerate and now harbors less than 100 functional genes. Which of the following process or processes can be attributed to the evolution of the mammalian sex chromosomes?
x chromosome inactivation
meiotic sex chromosome inactivation
translocation of genes from the y to autosomes
all above mentioned mechanisms
which of the following statements are true?
there is a gene that codes for gyrification of the cortex
the skull has no role in shaping the structure of the brain
complex structure emerges only because of physical constraints
morphogens are the only determinants of cell fate
none of the above
Mutations in the regulatory DNA sequence ZPA-regulatory sequence (ZRS), which regulates sonic hedgehog (SHH) expression, cause limb abnormalities in humans, mice and dogs. Recently it was discovered that loss of this ZRS region also causes loss of paired appendages, including pectoral fins, in jawed fish (Medaka, Oryzias latipes). The ZRS region was not found however in jawless fish, including amphioxus and the sea lamprey, which lack paired appendages. Which of the following statements is very likely true about genetic enhancers regulating sonic hedgehog expression?
The ZRS genetic enhancers likely emerged soon after separation between jawed and jawless vertebrates.
The ZRS genetic enhancers likely were lost in jawless fish after their separation from jawed vertebrates
Enhancers regulating SHH expression in paired appendages in mammals and jawed fish are an example of convergent evolution.
None of the above.
which of the statements belof is a benefit of meiosis?
it allows escape from muller's ratchet
beneficial alleles are separated due to recombination
a yeast meiosis leads to 4 spores as opposed to two daughter cells in mitoses
lateral gene transfer is no longer necessary
Related to Drosophila, which of the following statements is true?
Deletion of Polycomb proteins results in downregulation of Hox genes
Deletion of maternal-effect genes results in loss of broad body parts, such as anterior regions or posterior regions.
Deletion of Hox genes results in loss of segments in Drosophila.
Deletion of gap genes results in loss of egg polarity gene expression.
In the development of the nervous system, which is the correct order of events?
First, cells must be specified to be neurons, second, these neurons must make connections with their targets, third, the neurons must migrate to their final position, and fourth, the neurons refine their synaptic connections.
First, cells must be specified to be neurons, second, the neurons must migrate to their final position, third, these neurons must make connections with their targets, and fourth, the neurons refine their synaptic connections.
First, cells must migrate to their final position, second, these cells must be specified to be neurons, third, the neurons must make connections with their targets, and fourth, the neurons refine their synaptic connections.
. First, the prospective neurons must make connections with their targets, second, the neurons refine their synaptic connections, third, the neurons must migrate to their final position, and fourth, the cells are specified to become neurons.
There is no fixed order of events; different portions of the nervous system do things in different ways.
What is the biological purpose of the acrosome reaction?
to facilitate penetration through the corona radiata
to facilitate penetration of the zona pellucida
to prevent fertilization by a second sperm cell
to prevent premature activation of the oocyte
About Shh, which of the following statements is false?
Shh is a morphogen that is secreted by the posterior zone of polarising activity in tetrapod limbs.
The Shh pathway is critical for branching during lung development.
Shh is expressed just posterior of the segment boundary in Drosophila, stabilizing it through a negative feedback loop.
Ectopic anterior Shh expression in tetrapod limbs gives rise to preaxial polydactyly.
Severe mutations in Shh lead to cyclopia in mammals.
In which of the following processes is the gene engrailed not involved?
development of the cerebellum in mice
segment boundary stabilization in flies
dorsal-ventral axis specification in tetrapod limbs
germ cell migration in mice
which of the following statements is correct?
inhibiting rna pol II in the most posterior cells of a cellular blastoderm is necessary for pole cell development.
Radiation treatment of a syncytial embryo that only destroys DNA will abrogate pole cell development.
Fusing the untranslated region of nanos to the bicoid RNA will localize bicoid to the posterior part of the embryo, increasing pole cell formation.
Upregulation of RNA pol II in pole cells will allow for the stabilization of the germ cell developmental programme.
what is the role of e-cadherin in the morula?
generate tight junctions
generate gap junctions
mediate compaction
mediate trophoblast formation
Gynandromorphs are animals that contain physical male as well as female characteristics. Why are there gynandromorphs in insects but not in mammals?
Sex in insects is determined in a cell-autonomous fashion while in mammals it is hormonebased
Because even though insects have a Y chromosome, they also express female hormones, resulting in gynandromorphs. In mammals, it is only hormone-based.
In mammals, SRY is expressed from the Y chromosome in males, resulting in a cascade of gene and hormone expression. In insects, SRY is not present, leading to the possibility of mixed sex bodies.
Actually, there are gynandromorphs in mammals.
A similarity between the X chromosome dosage compensation mechanisms in Drosophila and mammals is that:
they are both repressing, leading to downregulation of genes located on an X chromosome.
they are non-coding-RNA dependent.
they result in a Barr body
they occur in the blastocyst stage of the embryo.
which of the following statements are true?
The autonomic nervous system is under conscious control.
There is no genetic predisposition for being faithful in a relationship.
The parasympathetic nervous system activates your fight or flight response.
There are olfactory stimuli that help humans decide who is related to them.
None of the above are correct.
What would happen if you injected b-catenin in a ventral-vegetal blastomere of an early frog embryo (before the blastula stage)?
Nothing, just normal development of the embryo
The anterior-posterior axis formation of the embryo will be accelerated.
Just a minor increase in size of the embryo.
Development of a second anterior-posterior axis.
Which of the statements concerning the induction of mesoderm in a Xenopus embryo is true?
There is an interaction between ectoderm and endoderm, and ectodermal cells produce signals to the endoderm to form mesoderm.
WNT-XNR interactions between ectodermal and endodermal cells in the middle of the blastula induce mesoderm formation.
the cells closer to the animal pole initiate mesoderm formation
mesoderm is induced after the closing of the neural tube formed from ectodermal cells
If the nerve supply to a newt limb is severed before amputation, how will this affect regeneration?
It will have no effect, since regeneration involves growth of new muscle, bone, and connective tissue.
Regeneration of most tissues will occur normally, but regeneration of the nerves will not occur
Outgrowth will occur, but the identity of the limb will be lost and normal proximo-distal patterning will not occur.
. A blastema will form but will not grow, and regeneration will fail
. No regeneration occurs, and the stump heals over as it would in a mammal.
The formation of the amnion allowed vertebrates
to increase the size of the embryo quickly due to the mother-embryo nutrient exchange
to increase the surface contact with air for better oxygen intake
the lay eggs outside of water
to protect the embryo from excessive heat
The epithelial-to-mesenchyme transition is important during gastrulation to
allow invagination
allow cell migration
mediate epiboly
allow lateral inhibition
In a chicken embryo, one morphogen that is produced from the Hensen’s node and diffuses anteriorly is
RA
FGF4
FGF10
shh
Stem cells are found throughout the body and often involved in homeostasis and repair of tissues. With respect to adult stem cells, which of the following statements is false?
stem cells are rare and slow dividing cells
stem cells require a niche to survive
stem cells have the capacity to self-renew
stem cells can give rise to multiple different cell types
convergent extension mediates
elongation and thinning of a tissue
filopodia lengthening of cells
tubule formation in a tissue
formation of bottle shaped cells
The ancestors of teleost fish and tetrapods arose through two whole genome duplications. Remnants of this event are still visible in our genome. For instance, the Hox gene cluster is present in four different clusters in teleost fish and tetrapods, whereas only one Hox cluster is found in flies. What is the most likely form of speciation associated with the arrival of the common ancestor of the teleost fish and tetrapods?
parapatric speciation
propatric speciation
sympatric speciation
allopatric speciation
Which of the following statements about Hox genes is false?
Hox genes are expressed in insects, crustaceans and vertebrates to pattern the anteroposterior axis.
The clusters Hoxa and Hoxd are important for patterning the limbs.
Generation of eye structures within the legs of Drosophila is a type of homeotic transformation because you are generating an extra structure somewhere else in the body
An interesting characteristic of Hox genes is co-linearity: their relative position in the genome correlates with their relative expression pattern along the antero-posterior axis in vertebrates.
The beta globin locus evolved from a common globin ancestral gene that we shared with our ancestors more than 200 million years ago. What was the main mechanism driving the evolution of the globin genes?
retrotransposition
duplication
inversion
deletion
