Test
Development
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Preguntas del test (62)
1What is lateral inhibition?
- AA sensory organ precursor cell emits an inhibitory signal to its neighbors to prevent them becoming the same cell.
- BA sensory organ precursor cell telling neighbors to become the same fate as itself.
2Evidence for lateral inhibition includes:
- AThe enlarging cell in grasshoppers will sent out a signal and nothign will happen
- BWhen the enlarging cell in grasshoppers is zapped with a laser, the neighbor takes on the role even if previously inhibited.
3Drosophila with too few hairs are _______, and too many are ______.
- AProneural; Neurogenic
- BNeurogenic; Proneural
4Neurogenic mutants:
- AEnd up with sense organ precursor absence.
- BEnd up with sense organ precursor cells neighboring each other
5Genetic mosaics: In the absence of a signalling cell, development will
- AFail
- BSucceed
6Genetic mosaics: In the absence of the receptor, development will
- AFail
- BSucceed
7Notch mutants:
- AMany cells in a region will develop as precursors, meaning notch is the receptor.
- BNo cells are becoming precursors.
8Delta mutants:
- ACells receive a signal from outside wild-type cells, and inside cells are too far away to receive the signal so become precursors. Delta must be the signal.
- Bmf
9Mutants for too many trichomes include:
- AGlabra1 (GL1), Transparent Testa Glabra1 (TTG1) and Glabra 3 (GL3).
- BTripychon (Try) and Caprice (Cpc)
10How can cells become in proportion to one another?
- ADirect-contact and Diffusion
- BSpaced patterns or lateral inhibition
11What regulates the spacing of sensory bristles in Drosophila?
- ADelta and Notch signalling
- BPie-1 and Par-1 signalling
12What is a morphogen?
- AA molecule which defines two or more cell fates and differing concentrations.
- BA molecule which causes morphological changes to a determined cell.
13What is a desirable property of a morphogen?
- ASlow diffusion to create a gradient
- BFast diffusion to allow a quick change
14Other than using a morphogen, what other method could be used to induce different cell fates?
- ASerial signalling
- BLateral inhibition
15Lin-3 is expressed by which cell?
- AThe anchor cell
- BP3
16Let-23 is expressed as an RTK on which cells?
- AP3-8
- BThe anchor cell and P4
17P3-8 are known as:
- AVulval precursor cells
- BC.elegans genitals
18Where is the highest Lin-3 concentration found?
- AP6
- BP3
19The correct cell fates to VPCs are:
- AP6 = Primary, P3/4/8 = Secondary, P5/7 = Tertiary
- BP6 = Primary, P3/4/8 = Tertiary, P5/7 = Secondary
20If all cells are destroyed in an ablation experiment except for p7, it will become:
- APrimary vulval cell
- BHypodermis
21A heat shock between 25-37 degrees cab express:
- ALin23
- BLin-3
22A weak heat shock will cause P3p to take on the
- ASecondary fate
- BContinue with the tertiary fate
23A constant heat shock at 37 degrees with high Lin-3 levels will give it a
- APrimary cell fate
- BRemain at tertiary
24If Lin-12 is removed:
- ADuplication of the anchor cell occurs and 3 primary cells are produced with no secondary.
- BAll cells become primary
25Lin-12 is not expressed as a receptor in
- AP6p because it produces Apx1, Dsl1 and Lag1.
- BAny of the P3-8p cells
26Lin-12 is expressed as a receptor mostly in
- Asecondary cells
- Bprimary
27Anchor cells make Lin-3 which set a gradient. At high concentration, primary cell fate is produced. P6p produces ligands which signals to neighboring cells to become secondary by responding with the Lin-12 receptors they possess.
- AVerdadero
- BFalso
28Epiboly is
- Awhere two layers of cells squash together to form one larger layer
- BWhen cells make strands
29Convergence extension is when
- AOne layer of cells intercalate towards each other to form one long strip of cells.
- BTwo layers fuse to make a thin one
30The animal pole is ________ and the vegetal pole is ________ before fertilization.
- Adark; light
- Blight; dark
31The xenopus embryo contains maternal mRNAs and proteins for housekeeping and developmental roles.
- AVerdadero
- BFalso
32Vg-1 is localised in the vegetal cortex and moves to the vegetal cytoplasm post fertilization to drive animal/vegetal identity.
- AVerdadero
- BFalso
33Ninety minutes after sperm entry, cortical rotation occurs.
- AVerdadero
- BFalso
34Cortical rotation allows some of the vegetal cortex to become closer to the animal region. Opposite the sperm entry site, the Nieuwkoop Centre is established.
- AVerdadero
- BFalso
35The NC sets the initial D/V polarity in the blastula
- AVerdadero
- BFalso
36Embryos with a NC develop
- ANormally, while only missing some ventral structures such as the gut. It is dorsalised.
- BIncorrectly
37The NC can be grafted onto the ventral side of the embryo to produce twin dorsal sides.
- AVerdadero
- BFalso
38UV light can block cortical rotation, therefore formation of the NC. This causes ventralized embryos to be produced.
- AVerdadero
- BFalso
39The effects of UV light can be rescued by reorientating the egg to mimic cortical rotation of by grafting an NC from another embryo.
- AVerdadero
- BFalso
40Embryos can become dorsalised by the treatment of
- ALithium
- BMagnesium
41Beta-catenin accumulates on the ________ side upon cortical rotation, where it moves into the _________ and activates a transcription factor which specifies the _________ region.
- Adorsal; nucleus; dorsal
- BVentral; ER; dorsal
42When B-catenin is injected into the ventral side of the cell, what is observed?
- AA new NC is specified an a second axis is formed.
- BIt accumulates dorsally as normal
43GSK-3 helps to degrade
- AB-catenin
- BBMP
44Dishevelled begins on the vegetal side and is moved dorsally due to cortical rotation
- AVerdadero
- BFalso
45Dishevelled inhibits GSK-3 allowing B-catenin to not be degraded
- AVerdadero
- BFalso
46Lithium inhibits GSK-3 too
- AVerdadero
- BFalso
47The Spemann Organiser
- Aarises above the NC
- BBelow the NC
48The endoderm is found in the _______ region, the ectoderm in the ________. The Mesoderm is in the ________ zone.
- Avegetal; animal; marginal
- Bdorsal; ventral; animal
49Mesoderm induction is dependent upon signals from the vegetal region turning the animal pole cells from ectodermal fate to a mesodermal fate.
- AVerdadero
- BFalso
50When a filter is placed between the A/V axis in Xenopus, mesoderm develops. We can conclude that
- Aa secreted signal is involved
- Bdirect cell contact is needed
51The animal cap will only respond to an inducing mesoderm signal between 4-11 hours after fertilization
- AVerdadero
- BFalso
52Ventral and dorsal mesoderm will not form the same structures, and the SpO is involved in this.
- AVerdadero
- BFalso
53When transplanting the SpO, a "dorsalling" signal is given allowing the dorsal mesoderm to form giving rise to the notochord.
- AVerdadero
- BFalso
54The four signal model of mesoderm induction includes:
- ASignal from vegetal pile to prime embryo for mesoderm induction
- BSignal from dorsal to prime
- CThe Nieuwkoop centre - specification of dorsal identity
- DThe Spemann Organiser - specifying ventral identity
- EThe Spemann Organiser - specify dorsal
- FSignals within the ventral mesoderm
55After fertilization, protein synthesis increases from stored maternal mRNA. Once cleavage reaches the 12 cell stage, zygotic proteins take over due to "mid-blastula" transition. This occurs at the same time as mesoderm induction.
- AVerdadero
- BFalso
56TGF-b family proteins are ligands which undergo signal transduction. They would be good candidates for signals and are probably involved in mesoderm induction.
- AVerdadero
- BFalso
57VegT is a maternal T-box transcription factor which regulates expression of TGF-B family members. When it is depleted there is no mesoderm.
- AVerdadero
- BFalso
58The third signal in mesoderm induction is a dorsalising signal and will
- Ablock BMP function, blocking TGF-b on dorsal side
- Ballow BMP to function
59BMP concentration differences account for mesoderm patterning
- AVerdadero
- BFalso
60Noggin is an antagonist of BMP expressed in the SpO.
- AVerdadero
- BFalso
61BMP is low at the SpO due to Noggin presence, but high at the ventral mesoderm.
- AVerdadero
- BFalso
62When Noggin, Chordin and Follistatin are removed from an embryo, BMP is found throughout the cell. Dorsal structures are lost.
- AVerdadero
- BFalso
Información
- Descripción
- Biomedical Sciences Test sobre Development, creado por Elizabeth James el 28/05/2015.
- Autor
- Elizabeth James
- Idioma
- English
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