Human Development and Cancer (16,17,18,19,20,21) Flashcards by Bronwen Delbridge

What is involved in cell division?

a. Cells maintain their size during cleavage due to the G1 and G2 phases
b. An original cell divides into many cells and each daughter cell receives a full copy of the genome
c. Cleavage does not occur until after differentiation and determination
d. The embryo remains the same size during later cell divisions due to the absence of the G1 and G2 phase

b. An original cell divides into many cells and each daughter cell receives a full copy of the genome

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What does not occur during differentiation?

a. All genes are expressed to the same degree in all cells
b. Internal structure and outward appearance of cells is established
c. Cells can become polarised
d. Differential gene expression occurs

a. All genes are expressed to the same degree in all cells

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How do drosophila neural stem cells divide?

a. GMCs divide into daughter neuroblasts
b. Symmetric division due to secretion of wingless
c. Asymmetric division due to the localisation of prospero
d. By inhibiting the BMP signalling pathway

c. Asymmetric division due to the localisation of prospero

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Which is not a common signalling pathway?

a. TGFB/BMP
b. Hedgehog
c. FGF (MapK)
d. Hippo/Yorkie

d. Hippo/Yorkie

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What is involved in morphogenesis?

a. Apoptosis is not a normal part of morphogenesis
b. Cells develop through cell divisions due to cleavage and growth
c. Once morphogenesis begins, cells cannot migrate
d. Morphogenesis only involves MET

b. Cells develop through cell divisions due to cleavage and growth

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What is not an example of collective cell behaviour?

a. Epithelial folding
b. Convergent extension
c. Cleavage and Growth
d. Epithelial branching

c. Cleavage and Growth

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What does twist do?

a. It is a determinant in the neuroblasts of drosophila during asymmetric division
b. It regulates genes for epithelial folding, EMT and migration
c. It causes MET of cells in the drosophila embryo
d. It is expressed in the dorsal side of human embryos to regulate many genes at once

b. It regulates genes for epithelial folding, EMT and migration

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What is not a benefit of drosophila as a model organism?

a. It has a large genome like humans
b. Cultivation is short and easy
c. The embryo is easy to visualise
d. Ready access to genetic resources

a. It has a large genome like humans

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What accurately describes a benefit of a specific model organism?

a. Flies can be frozen and kept alive to be studied at a later date
b. Worms can be genetically manipulated via mRNA injections to the zygote (Frog)
c. The cell linage of chicks has been determined
d. Zebrafish have a clear embryo and are genetically tractable vertebrates

d. Zebrafish have a clear embryo and are genetically tractable vertebrates

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• To form the blastocyst, the morula must escape the zona pellucida in order to contact the uterus epithelium.

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• Cell division of B and T lymphocytes and sperm cells results in daughter cells receiving a full copy of the genome.

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• Cells in the presumptive eye region in drosophila are determined at the gastrula stage.

F neurala)

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• In propspero mutants, GMCs are transformed into self-renewing neural stem cells.

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• There is no G1 and G2 stage during cleavage.

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• EMT involves the formation of a polarise epithelium and MET involves the formation of migratory cells.

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• Most cases of achondraplasia result from a glycine to arginine mutation in the FGFR3 gene.

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• Cancer can develop when regulatory genes are mutated and cells escape the strict controls of development.

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What correctly describes the events from ovulation to implantation?

a. The morula forms in the ovary
b. First cleavage occurs in the uterus
c. Fertilisation occurs in the fallopian tube
d. The blastocyst develops in the ovary

c. Fertilisation occurs in the fallopian tube

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What occurs during fertilisation?

a. When a spermatozoa contacts the zona pellucida, the egg release proteolytic enzymes to break down the zona pellucida. (sperm does)
b. A spermatozoa contacts the oocyte after the second meiotic division and creation of the 2nd polar body and female pronucleus
c. Once the sperm pronucleus is delivered into the oocyte, the egg releases enzymes that modify the surface and prevent more sperm from entering
d. The male and female pronuclei fuse to form the first haploid cell known as the zygote

c. Once the sperm pronucleus is delivered into the oocyte, the egg releases enzymes that modify the surface and prevent more sperm from entering

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What is a feature of the morula?

a. It describes the embryo at the 8 cell stage
b. It develops following cleavage and rapid G1 and G2 cycles
c. It describes the embryo at the 16 cell stage
d. It develops following cleavage of the blastocyst

a. It describes the embryo at the 8 cell stage

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Epithelial cells:

a. Are polarised along the dorsal-ventral axis
b. Are detached from neighbour cells
c. Have tight junctions to prevent molecules and water passing between them
d. Have gap junctions for adhesion

c. Have tight junctions to prevent molecules and water passing between them

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What happens during compaction?

a. E-cadherin is down-regulated in cells
b. The first epithelium is formed
c. Cells lose polarity in order to maximise contact
d. Microvilli can be restricted to the basal surface

b. The first epithelium is formed

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How does the inner cell mass form?

a. Through symmetric divisions within the morula
b. During cleavage and compaction of the blastocyst
c. From the unpolarised inner cell that results from asymmetric division in the morula
d. When E-cadherin expression is turned off in the morula

c. From the unpolarised inner cell that results from asymmetric division in the morula

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How do the first major cell linages split?

a. Outer cells in the morula express Oct4
b. Oct4 and Cdx2 mutually activate one another
c. Inner cells in the moruala express Cdx2
d. Mutual repression of Cdx2 and Oct4 stabilises cell differentiation

d. Mutual repression of Cdx2 and Oct4 stabilises cell differentiation

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How do the epiblast and hypoblast develop? a. Epiblast cells express nanog which represses GATA6 b. Hypoblast cells lack GATA6 expression c. FGF4 directly activates nanog expression in epiblast cells d. Hypoblast cells express nanog in order to up-regulate GATA6

a. Epiblast cells express nanog which represses GATA6

What is not a feature of gastrulation? a. It is the first event of morphogenesis and involves body axes being defined b. The Primitive streak forms in a region where epiblast cells undergo EMT and enter the space between epiblast and hypoblast layers c. Cells exit the primitive streak and intercalate in outer hypoblast layer to form endoderm d. The endoderm only contains epiblast cells

d. The endoderm only contains epiblast cells

What is a feature of the germ layers? a. Epiblast cells coming through the primitive streak take on a mesodermal fate b. The mesoderm can give rise to the gut and lungs c. Endoderm forms from epiblast cells that don’t go through the primitive streak (ectoderm) d. Ectoderm gives rise to muscle and connective tissue

a. Epiblast cells coming through the primitive streak take on a mesodermal fate

What occurs during mesodermal cell migration? a. Ecad is up regulated to encourage a MET transition b. FGF4, FGF8 are expressed in the primitive streak c. FGFR1 interactions lead to Ecad expression via Snail d. FGFR1 mutants demonstrate repressed Ecad expression

b. FGF4, FGF8 are expressed in the primitive streak

What occurs through the FGF pathway? a. It leads to Brachyury expression in mesodermal cells b. It signals for sperm to release proteolytic enzymes upon contact with the zona pellucida c. Snail is repressed so that Ecad can be expressed d. It represses Brachyury which is a regulator of endodermal cell fate

a. It leads to Brachyury expression in mesodermal cells

• Ecadherin (epithelial cadherin) is the major cell-cell adhesion molecules in adherens junctions.

• Cancer metastasis can result when epithelial cell polarity factors are lost.

• During blastocyst formation, the blastocyst appears to pulse as water is pumped out of the morula.

• The zona pellucida must be intact for the blastocyst to make contact with the uterine wall epithelium.

• Embryonic stem cells are derived from the hypoblast of the inner cell mass.

• The amniotic cavity forms within epiblast cells and the primitive yolk sac forms within hypoblast cells.

• During gastrulation, the ectoderm is the first germ layer to form.

F (endoderm)

What defines the body axes and determines the body plan? a. The neural tube b. Epidermis/Mesoderm junctions c. The primitive streak d. Presomitic mesoderm

c. The primitive streak

What occurs in neurulation? a. The neural tube forms the neural plate b. Epithelial folding of the neural plate leads to the formation of the neural tube c. A region of mesoderm thickens to form the neural plate d. The neural tube results from convergent extension

b. Epithelial folding of the neural plate leads to the formation of the neural tube

What is a feature of neural tube defects? a. An open anterior neuropore results in spina bifida b. They affect 1 in 100 pregancies (1 in 1000) c. An open posterior neuropore results in ancephaly d. They can involve mutations in genes in the PCP pathway

d. They can involve mutations in genes in the PCP pathway

What is not a pathway associated with neural tube defects? a. Wnt/B-catenin pathway b. PCP pathway c. Hedgehog pathway d. TGFB/BMP pathway

a. Wnt/B-catenin pathway

What is not a feature of neural crest cells? a. They undergo SLUG dependent EMT b. They arise from the region between the neural plate and epidermis c. They form epithelial cells which insulate the spinal cord d. They are called the “fourth germ layer” due to their ability to differentiate to many cell types

c. They form epithelial cells which insulate the spinal cord

What is false about Waardenburg Syndrome? a. The phenotype is hypo-pigmentation and deafness b. Mutations to the MITF gene are dominant negative c. The mutation can be mapped to the long arm of chromosome 3 or 13 d. The white forelock arises due to a failure in melanocyte migration

c. The mutation can be mapped to the long arm of chromosome 3 or 13

Which mutation could not cause a Waardenburg Syndrome phenotype in mice? a. BMP- b. KIT- c. SLUG- d. MITF-

a. BMP-

What is a feature of neural stem cells? a. They stretch from the basal side of the neural tube to the apical side b. They exist in a multi layered epithelium c. The nuclei move up and down in the ventricular zone during the cell cycle d. Symmetric divisions help to generate diversity

c. The nuclei move up and down in the ventricular zone during the cell cycle

How is the neural tube patterned? a. BMP4 localises at the notochord and floor plate b. The local level of BMP4 and Shh determines neuron differentiation c. Shh is expressed in the epidermis and roof plate d. Neuron differentiation solely depends on BMP4 levels

b. The local level of BMP4 and Shh determines neuron differentiation

What is a feature of HPE? a. It is a structural anomaly of the developing hind brain b. The phenotype is always severe disfigurement c. 1:250 live births are impacted d. It results from incomplete cleavage of the forebrain

d. It results from incomplete cleavage of the forebrain

What is a feature of Spondylocostal Dysostosis (SCDO1)? a. It results in incomplete cleavage of the forebrain b. It can be caused by a mutation in DLL3 which is involved in the notch pathway c. The disease is usually mild and leads to malformed muscle tissue d. The disease cannot occur in vertebrates

b. It can be caused by a mutation in DLL3 which is involved in the notch pathway

What happens during somitogenesis? a. Notch signalling is turned on and off up the spine in a wave like pattern b. Mesodermal cells undergo an EMT transition c. Somites form in the region where notch activation begins d. Notch degrades Lunatic Fringe proteins

a. Notch signalling is turned on and off up the spine in a wave like pattern

How can notch signalling travel like a wave up the spin during somite formation? a. Once notch is activated, Lfng is activated and turns off notch b. The notch protein degrades quickly following translation c. Lunatic Fringe is repressed by notch activation d. Notch and Lfng interact in a linear pathway

a. Once notch is activated, Lfng is activated and turns off notch

What is not a feature of DCC? a. A lack of DCC means that neurons cannot cross the midline and connect with motor neurons on the same side b. It is a receptor for the diffusible axonal chemoattractant Netrin1 c. Neurons expressing DCC extend to the floor plate where netrin is expressed d. When growing towards the source of Netrin, neurons do not cross the midline

d. When growing towards the source of Netrin, neurons do not cross the midline

• Grafting the primitive streak from one chick embryo to another can lead to the formation of a second body axis.

• Neural epithelial cells divide at the basal surface of the neural tube.

• Shh helps to pattern the neural tube by localising at the epidermis and roof plate.

• The ventral midline is specified by the sonic hedgehog pathway.

• Bilateral structures, such as the eye field and nostril, fail to separate when the Shh activator Jervine is introduced to mouse embryos.

• Congenital mirror movements disorder can be caused from a mutation in the DCC gene where the splice donor sequence is mutated, exon 6 is skipped and a frame shift mutation results in an early stop codon.

Which type of cancer is correctly matched with its tissue of origin? a. Melanoma forms in blood cells b. Sarcoma forms in connective tissue c. Carcinoma forms in the nervous system d. Leukaemia forms in the lymphatic system

b. Sarcoma forms in connective tissue

What is not a hallmark of cancer? a. Sustaining proliferative signalling b. Invade and metastasise c. Replicative immortality d. Promote cell death

d. Promote cell death

What is senescence? a. A cell is alive but not actively proliferating and in an irreversible state of arrest b. A cell is actively proliferating to increase the cell population c. A cell is exhibiting increased cell division and decreased apoptosis d. A cell is expressing at least 3 of the hallmarks of cancer

a. A cell is alive but not actively proliferating and in an irreversible state of arrest

What is a feature of an oncogene? a. It’s normal action is to prevent the formation of a cancer cell b. They usually promote differentiation and cell death c. They usually promote cell proliferation d. Examples are p53, Rb and ECadh

c. They usually promote cell proliferation

What is a feature of a tumour suppressor gene? a. Ras and Myc are well known examples b. They can limit cell proliferation and promote cell death c. They are often involved in promoting motility and cell growth d. Only one allele needs to be mutated for a cell to become cancerous

b. They can limit cell proliferation and promote cell death

What happens in Burkitt’s Lymphoma? a. There is a T(8;14)(q24;q32) double deletion b. Translocation of the myc gene results in it being regulated by the Ig heavy chain enhancer c. There is a fusion between BCR and the c-abl oncogene d. Myc expression is down-regulated due to a premature stop codon

b. Translocation of the myc gene results in it being regulated by the Ig heavy chain enhancer

What happens in chronic myeloid leukaemia? a. C-ABL and BCR fuse and oligermisation leads to constitutive activation of the ABL tyrosine kinase domain b. A T(9;22)(q34;q11) translocation leads to ABL being constitutively activated by the BCR enhancer c. A chimeric c-ABL-bcr protein is produced with down-regulated tyrosine kinase activity d. The constitutively active BCR-ABL onco-protein drives apoptosis of hematopoietic cells

a. C-ABL and BCR fuse and oligermisation leads to constitutive activation of the ABL tyrosine kinase domain

What is most likely to cause thyroid cancer? a. Gene amplification leading to the overproduction of a normal protein b. Fusion of actively transcribed gene rpdoicts to produce a hyperactive fusion protein c. A deletion or point mutation in coding sequence that leads to a hyperactive protein made in normal amounts d. Chromosome rearrangement that causes a gene to be regulated by a constitutive enhancer

c. A deletion or point mutation in coding sequence that leads to a hyperactive protein made in normal amounts

What is involved in the Knudson two hit model? a. Loss of heterozygosity occurs following the first hit/mutation of a tumour suppressor gene b. Inactivation of a tumour suppressor gene can only occur as a result of genetic mutations c. Mutations to tumour suppressor genes are gain of function d. Both alleles of a tumour suppresser gene must be mutated for cell transformation to occur

d. Both alleles of a tumour suppresser gene must be mutated for cell transformation to occur

What are Rb and p53? a. Rb is a oncogene whilse p53 is a tumour suppressor gene b. Both are tumour suppressor genes which regulate the cell cycle c. Rb promotes apoptosis and DNA repair whilst p53 regulates the cell cycle d. Both are proto-oncogenes that encourage cell proliferation

b. Both are tumour suppressor genes which regulate the cell cycle

What does Rb do? a. It phosphorylates and actives E2F to promote S phase b. When a faulty copy is inherited, children usually go on to form a tumour in one eye c. It is phosphorylated by G1-CdK which leads to the activation of E2F d. An absence of Rb would result in cell cycle arrest

c. It is phosphorylated by G1-CdK which leads to the activation of E2F

What is a feature of p53? a. P53 mutations are only associated with rare cancers b. It encodes a DNA binding protein that controls genes for apoptosis and DNA repair c. It can prevent senescence and apoptosis d. It leads to the expression of genes that lead to telomere shortening

b. It encodes a DNA binding protein that controls genes for apoptosis and DNA repair

How can HPV cause cancer? a. The viral E6 protein binds to p53 and encourages its degradation b. Viral E7 proteins sequester and inhibit Rb in the cytoplasm c. The viral E6 protein ubiquitinates Rb and encourages its degradation d. Viral E7 is a proteolytic enzyme that cleaves p53

a. The viral E6 protein binds to p53 and encourages its degradation

Which statement about mutation patterns is correct? a. Most oncogene mutations are truncating b. Oncogenes and tumour suppressor genes follow identical patterns of mutation c. Truncating mutations are rarely found in tumour suppressor genes d. In oncogenes, repeated mutations are often found at a key amino acid residue

d. In oncogenes, repeated mutations are often found at a key amino acid residue

What is a feature of Li-Fraumeni syndrome (LFS)? a. It results from loss of function germline mutations inherited in both p53 alleles b. Females and males with LFS have a 100% chance of developing some form of cancer c. Cancer predisposition results due a germline mutation in one copy of p53 d. Males with LFS are more likey to develop cancer as p53 is an X linked gene and they only have one copy

c. Cancer predisposition results due a germline mutation in one copy of p53

• Cancer is a genetic and cellular disease.

• About 80% of human cancers are sarcomas.

• Angiogenesis is when the tumour mass is invaded with blood vessels and leads to the cancer receiving nutrients.

• The promotion of DNA repair systems results from the action of tumour suppressor genes such as p53.

• For a mutation in a proto-oncogene to result in cancer both alleles must be mutated and this is referred to as the Knudson two hit theory.

F (Tumour suppressor gene)

• Myc promotes cell proliferation and angiogenesis.

• The majority of p53 mutations occur in the DNA binding domain.

What is involved in metastasis of the liver? a. Cells grow as a benign tumour in capillaries b. Micro-metastasis occurs in the blood stream c. After traveling in the blood, cells can adhere to the blood vessel wall in the liver d. Cells escape blood vessels to colonise the epithelium

c. After traveling in the blood, cells can adhere to the blood vessel wall in the liver

How can hypoxia link to angiogenesis? a. Cells on the boundaries of tumours become starved of oxygen and are sensed by HIF1a b. In hypoxic conditions, VEGF is activated and induces vesicular sprouting c. When oxygen level are high, HIF1a builds up and promotes the transcription of VEGF d. A lack of oxygen leads to the degradation of HIF1a

b. In hypoxic conditions, VEGF is activated and induces vesicular sprouting

What supports the ability of circulating tumour micoembolis to metastasise? a. In mice, multi coloured CTM clusters were only present in 2% of the blood yet caused over 50% of metastatic events b. CTM clusters directly activate VEGF to induce sprouting of vessels c. In mice multi coloured CTM clusters were present in 50% of the blood yet caused only 2% of metastatic events d. CTCs are much more common in secondary tumours and CTMs are more common in primary tumours

a. In mice, multi coloured CTM clusters were only present in 2% of the blood yet caused over 50% of metastatic events

What is a feature of the CellSearch system? a. It is used to detect cancer stem cells and transit amplifying cells b. It recognises cytoplasmic molecules that specifically mark CTCs c. It can only be used to detect CTCs from carcinomas as it detect epithelial cell surface markers d. Patients with high CTCs had higher survival rates than those with low CTC levels

c. It can only be used to detect CTCs from carcinomas as it detect epithelial cell surface markers

What is a feature of chromosome instability? a. It refers to having an abnormal number of chromosomes b. It can occur due to mutations in genes involved in the DNA repair response c. It often results in polyploidy d. It is a specific term used to describe gaining chromosomes via translocation

b. It can occur due to mutations in genes involved in the DNA repair response

What kind of tissue is most susceptible to cancer? a. Critical organs that do not undergo self-renewal b. Epidermal tissue which doesn’t contain stem cells c. Tissue that generates blood cells involved in immunity d. Self-renewing tissues that contain stem cells

d. Self-renewing tissues that contain stem cells

Which statement about cancer stem cells is true? a. They can divide indefinitely but do not have the capacity to self-renew b. They divide quickly and are therefore resistant to chemotherapy c. They provide an explanation for relapse as they survive cancer treatment d. Drugs that target a solid tumour will also remove CSCs

c. They provide an explanation for relapse as they survive cancer treatment

What transcription factor promotes metastasis and invasiveness? a. DCC b. Ecadherin c. pVHL d. Twist

d. Twist

What does Twist do? a. It drives mesenchymal to epithelial transition (MET) b. It causes EMT of cells on the central side of the embryo c. It is only induced after embryonic development d. It is down-regulated in many cancers and used as a prognostic

b. It causes EMT of cells on the central side of the embryo

Which genes are often mutated in colorectal cancer? a. P53 mutations cause an overactive Wnt pathway b. Kras mutants cause a lack of DNA repair c. APC mutants destroy B-catenin and down-regulate the Wnt pathway d. P53 mutants lack efficient DNA repair

d. P53 mutants lack efficient DNA repair

What is a feature DCC? a. It is a netrin receptor that represses the growth of neurons b. It triggers apoptosis when netrin is absent c. There is a loss of heterozygosity of DCC in 20% of colorectal cancers d. When netrin binds DCC, a cell undergoes apoptosis

b. It triggers apoptosis when netrin is absent

How do netrin and DCC interact in the colon? a. Both are expressed at the vilus core where there are high levels of apoptosis b. Netrin is expressed in the crypt where new cells are produced c. DCC is degraded when epithelial cells reach the villus tip to signal apoptosis d. Netrin is absent in the crypt which leads to the apoptosis of epithelial cells expressing DCC

b. Netrin is expressed in the crypt where new cells are produced

How do BRAF mutations link to melanoma? a. Mutant BRAF can lead to constitutive activation of the MapK pathway b. Successful BRAF inhibitors often result in full remission c. Mutations in BRAF result in down regulation of cell DNA repair pathways d. Inhibiting constitutive BRAF selects for new repressing mutations in upstream MapK pathway components

a. Mutant BRAF can lead to constitutive activation of the MapK pathway

• Following EMT, tumour cells can undergo intravasation and become circulating tumour cells.

• Secondary tumour formation requires extravasation and MET.

• CTCs are more likely to cause metastasis than CTMs.

• Cancers are most likely to arise in childhood.

• Many cancers are due to mutations in genes involved in the DNA damage response.

• Netrin inhibits metastasis and DCC promotes metastasis.

• Cells that express their own netrin are capable of metastasis even in the presence of DCC.

What cannot be used to measure levels of gene expression? a. Microarray b. Southern Blotting c. RNAseq d. qPCR

b. Southern Blotting

What is a feature of gene expression in inner cell mass cells? a. Sox2 shows a bimodal expression pattern during the whole developmental period b. By day 4, all cells express gata6 c. Most genes are expressed stochastically in the early stage d. Gene expression in individual cells follows a strict pattern from the early stages of development

c. Most genes are expressed stochastically in the early stage

What can RNAseq show about glioblastoma? a. There are low levels of variability at the chromosome level b. Chromosome 7 is often gained c. Each tumour cell will have an identical RNAseq profile d. Chromosome 10 is often gained

b. Chromosome 7 is often gained

What is not used to construct gene ontology? a. Biological processes b. Amino Acid composition c. Cellular components d. Molecular functions

b. Amino Acid composition

Which best describes a technique used to analyse a list of genes? a. STRING shows the relationship between genes b. chEA detects orthologues in other mammals c. Enrichr detects common transcription factors that interact with all of the listed genes d. STRING and Enrichr detect pathways likely to interact with the genes

a. STRING shows the relationship between genes

• Nanog is a crucial element of a stem cell and is central in the regulating the network of genes that mark pluripotency.

• In vitro, intestinal stem cells that express LGR5 develop into organoids which form crypt like structures and differentiated cell types like paneth cells.