Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

eBMS2021 > TOPIC E: Dev Biology > Flashcards

TOPIC E: Dev Biology Flashcards

1
Q

What are descriptive studies

A

Looking at expression patterns of mRNAs, non coding RNAs and proteins, fate mapping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are manipulative studies

A

Altering a system and observing the effects, gene knockout, transplantation, adding a drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is fate mapping

A

Based on lineage tracing where a labelling group is added to cells of an embryo to see what they become in adult tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Invertebrates animal model

A

Fly and round worm

ADV
Easy to keep and modify, rapid life cycle

DIS
Largely differing anatomy to humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Lower vertebrates animal model

A

Zebrafish and clawed frog

ADV
easy to keep and manipulate, can add factors to environment (water)

DIS
Distant from humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Higher vertebrate animal model chicken

A

Chicken

ADV
not in utero easy to manipulate

DIS
Longer life cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Higher vertebrate animal model mouse

A

Mouse

ADV
same organs and diseases as humans, easy to maintain

DIS
Embryos in utero, can be expensive, some phenotypes differ to human

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an epithelial mesenchymal transition

A

Where an epithelial cell becomes a mesenchymal cell to enhance development

Less polarised
Motile not attached to other cells or membrane
Lie within matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is cell fate

A

Developmental destination of a cell if left undisturbed in the embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is specification and determination of cell fate

A

Specification: Cell fate is biased but can still be reversed if manipulated

Determination: Specified to form a specific cell type irreversibly, will differentiate autonomously if placed in different region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is cell fate restriction governed by

A

Cells genome (gene expression)

Cells history (factors it has been exposed to)

Interaction with neighbours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is pattern formation

A

The developmental process where cells acquire different identities depending on their relative spatial positions in the embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the steps of pattern formation

A 
Cell proliferation
Cell migration
Changes in cell shape and size
Cell differentiation
Cell interaction (other cells and ECM)
Apoptosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is pattern formation influenced by

A

Differential gene expression

Signalling between cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does differential gene expression influence pattern formation

A

Interaction between transcription factors inside cells and signalling molecules from neighbouring cells cause differential gene expression

Changes in cell behaviour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the regulatory elements and transcription factors controlling differential gene expression

A

Promoters: initiate gene expression

Enhancers: Bind activating factors

Inhibitors: bind inhibitory factors

Transcription factors bind to regulatory elements and play a role in gene expression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Explain what the HOX gene cluster is

A

Homeobox DNA sequence is found within genes involved in anatomical development and morphogenesis

Homeobox genes clustered together are called HOX genes

4 hox clusters (abcd)

Collinear with position along chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a homeotic transformation

A

Where a body part develops as a different body part due to mutation of HOX genes

Sometimes the overlap of HOX genes prevents this from occurring in humans (known as functional redundancy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does signalling influence pattern formation

A

Induction is a change in cell fate due to signals sent from other cells. Limited repertoire used over and over.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is lateral inhibition

A

Where cells send inhibitory signals to neighbouring cells to alter behaviour.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the 2 types of signalling cascades induction paracrine factors can cause

A

Protein kinase activity (FGF and TGF-beta)

Second messenger systems (Hedgehog and Wnt)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Outline fibroblast growth factor pathway

A

FGF activates Receptor tyrosine kinase MAPK pathway

on nucleus, activates transcription factors

23
Q

Outline hedgehog pathway

A

Hedgehog binds to patched receptor which activates SMO to move into cilium so Gli is not broken down and transcriptional activation can occur

24
Q

Outline Wnt pathway

A

Wnt binds to a frizzled receptor causing destruction complex to bind and be inhibited. beta-caterin can then act as a transcription factor

25
Q

Outline transforming growth factor - beta pathway

A

TGF-beta binds to serine/threonine kinase receptor. Activates Smad proteins which target gene expression

26
Q

What are morphogens

A

Secreted, diffusible molecule that can influence fat of a field of neighbouring cells via a concentration gradient

changes in dose changes the genes activated

27
Q

What is morphogenesis

A

Organisation of form and shape of cells and tissues.

28
Q

what factors affect morphogenesis

A

Direct cell-cell adhesion

Cell migration

29
Q

How does direct cell-cell adhesion affect morphogenesis

A

Cells develop differential affinity to sort with similar cells

boundaries created by cell adhesion molecules

30
Q

What are cadherins

A

Calcium dependent adhesion molecules

E-cadherins are on most early embryonic cells, and later in epithelial tissues.

N-cadherins are on neural cells

P-cadherins are on placental cells

31
Q

How does cell migration affect morphogenesis

A

EMT causes morphogenesis by changes in characteristics

Change in polarity

Interaction with ECM

Motile force from actin and myosin

32
Q

What are the major phases of embryonic development

A 
Fertilisation
Cleavage
Blastocyst formation
Implantation in uterus
Gastrulation
Neurulation
Growth and organogenesis
33
Q

What is regulative ability of an embryo

A

Regulation of production to ensure normal structures are formed

e.g. If some cells are removed, the embryo will ramp up production to remake the cells

34
Q

Explain cleavage

A

Rapid cell division without size expansion

The individual cells are called blastomeres and undergo compaction

Tightly joined cells form the morula

Blastocyst forms with trophoblast and inner cell mass

35
Q

What are the trophoblast and ICM

A

Trophoblast is the outer layer of cells which becomes the cyto- and syncytio- trophoblast and then part of the placenta.

The ICM becomes the epiblast and hypoblast which will later become the embryo and yolk sac

36
Q

How are cells determined to become trophoblast or ICM

A

Inside outside hypothesis: Cells on inside become ICM and outside become trophoblast

Cell polarity model: If a cell divides parallel to zona pellucida it will become the trophoblast, if it divides perpendicular it becomes the ICM

37
Q

What are the key transcription factors in the blastocyst

A

Oct4 for ICM formation, expression of pluripotency

Cdx2 for trophoblast formation

Nanog for epiblast formation

Gata6 for hypoblast formation

38
Q

What is the gastrula

A

This is where the epiblast has become the 3 germ layers (a trilaminar disc)

39
Q

What is the primitive streak

A

Ridge of cells along the axis of the embryo

its formation marks the start of gastrulation

40
Q

What is the anterior visceral endoderm (AVE)

A

An extra embryonic tissue made of specialised cells in the hypoblast

41
Q

Explain the starting signalling process of gastrulation

A

Together the primitive streak and AVE signal for gastrulation

BMP4 comes in and instructs cells of epiblast to make Wnt and Nodal.

AVE instructs epiblast to make Letty 1 and cerberus which restrict Wnt and Nodal to the posterior pole, causing the primitive streak.

At top of primitive streak is the node, which produces its own signals

42
Q

Explain the movement of gastrulation through the primitive streak

A

Cells that pass through the node of the primitive streak will form part of the notochord, neural tube and head structures

Cells passing through the rest of the streak will produce the germ layers

Epiblast moves through, displacing hypoblast and first forming the endoderm and then the mesoderm, the remain epiblast cells become the ectoderm

43
Q

What are the different types of potency

A

totipotent: make any cell type, zygote
pluripotent: most cell types, inner cell mass
multipotent: lineage restricted, germ layers
unipotent: one cell type e.g. neurons

44
Q

Examples of tissues from each of the germ layers

A

Ectoderm: epidermis, CNS, neural crest cells

Mesoderm: Skeleton and muscles, dermis of skin

Endoderm: Epithelial lining of GI tract and associated organs and lining of respiratory, excretory and reproductive tract

45
Q

Where do the 4 main tissues of the body arise from

A

Epithelium (all)

CT (mesodermal)

muscle (mesodermal)

nerve (ectodermal)

46
Q

Outline neurulation

A

Production of the notochord and neural tube

47
Q

Outline sonic hedgehog role in neurulation

A

Induction of the neural tube is by sonic hedgehog (Shh) signalling from the underlying notochord. Induces neural plate to form and fold into the neural tube

48
Q

What are the 3 types of stem cells

A

Embryonic stem cells: from ICM

Adult stem cells: from adult tissue

iPSC: induced pluripotent stem cells due to reprogramming

49
Q

What characteristics are proof of stem cell ability

A

expresses cell type specific markers in vitro

behave as the desired cells in vivo

Can self renew

50
Q

Where can ASC be found

A

bone marrow, skin, gut and brain

haematopoietic stem cell, multipotent, red and white blood cells

mesenchymal stem cell, multipotent

51
Q

What factors are used to produce iPSC

A

Oct4: activates Nanog for pluripotency

C-Myc: opens chromatin accessible to Sox2, Oct4 and nanog

Klf4 prevents cell death

52
Q

What are the 2 types of cloning

A

Reproductive cloning: making a duplicate animal

Therapeutic cloning: Disease therapy

53
Q

What is somatic cell nuclear transfer (SCNT)

A

where the nucleus of an ovum replaced into a somatic cell. iPSC can skip this step

eBMS2021 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions