BIO 351 Exam 1 Quiz and Clicker Q's

You have created a knock out of the gene Nkx2.5. Which of the following most accurately describes what you have done? 1.Replaced the wild type Nkx2.5 alleles with a neomycin resistance gene in ES cells using homologous recombination. 2.Replaced the wild type Nkx2.5alleles with a neomycin resistance gene in ES cells using nonhomologous recombination. 3.Cloned the promoter of Nkx2.5 upstream of green fluorescent protein and introduced it into the genome by nonhomologous recombination. 4.Cloned promoter of Nkx2.5 upstream of green fluorescent protein and introduced into the genome by homologous recombination.

1. Replaced the wild type Nkx2.5 alleles with a neomycin resistance gene in ES cells using homologous recombination.

Which of the following is a true statement about a transgenic organism? 1.A transgene is in all cells of an embryo. 2.A transgene is only in a subset of cells of the embryo. 3.A transgene is only in germ cells (eggs and sperm). 4.A transgene is not found in cells.

1.A transgene is in all cells of an embryo.

Embryonic stem (ES) cells represented a scientific breakthrough and allowed for the development of technologies such as knock-out mice. Which of the following best describes the key attributes of ES cells? 1.They are monopotent. 2.They are pluripotent and can be manipulated in culture. 3.They are multipotent but cannot become germ cells. 4.They are totipotent and cannot be manipulated in culture.

2. They are pluripotent and can be manipulated in culture.

If you have a mouse strain that expresses Cre recombinase under the control of a heart-specific enhancer, which of the following is true? 1.All cells in the mouse express Cre recombinase protein. 2.All cells except those in the heart will exhibit Cre recombinase expresion. 3.Only cells in the heart express Cre recombinase protein.

3. Only cells in the heart express Cre recombinase protein.

If you have ES cells that survive double selection after electroporation with the targeting vector this indicates which of the following? 1.No recombination of the targeting vector to the locus of interest has occurred. 2.The targeting vector has randomly integrated into the genome. 3.The targeting vector has integrated into the genome through homologous recombination at the target locus.

3. The targeting vector has integrated into the genome through homologous recombination at the target locus.

You have bred a mouse expressing Cre under the control of a liver-specific promoter and one allele of a 'floxed' gene X. Which of the following statements is FALSE? 1.Only one functional allele of Gene X will be expressed in the liver. 2.The "loxp-Gene X-loxp" DNA sequence will be present in the epidermis. 3.Two functional alleles of Gene X will be expressed in the heart. 4.The "loxp-Gene X-loxp" DNA sequence will be present in the liver.

4.The "loxp-Gene X-loxp" DNA sequence will be present in the liver.

The following is a diagram from Ensembl of the MC1R gene that regulates red hair color. Which of the following represents the 5' UTR?

A. A is the first exon and 5' UTR

A plasmid is which of the following? A.Circular extrachromosomal DNA B.A chromosome C.A protein D.A bacteria

A. Circular extrachromosomal DNA

The following pathway diagram shows juxtracrinesignaling. The ______________ ligand is on the inducing cell and _____________ is the receptor on the responding cell. A. Delta; Notch B. Delta; CSL C. Notch; Delta D. Notch; CSL

A. Delta; Notch

What is the expected result when siRNA is used in a cell? A.It reduces expression of a specific protein. B.It reduces transcription rate of a specific gene. C.It interferes with cell division. D.It enhances gene expression of a specific gene.

A. It reduces expression of a specific protein.

Which of the following is an important role of the stem cell niche? A. Maintains self-renewal and potency of stem cells B. Limits potency of stem cells C. Blocks proliferation and self-renewal D. Limits differentiation of monopotent stem cells only

A. Maintains self-renewal and potency of stem cells

Within the early embryo the primary heart field develops in response to high levels of bone morphogenic proteins (BMPs) and fibroblast growth factor 8 (FGF8) at the rostral end of the embryo. This is an example of which of the following? A. Morphogen gradient B. Autocrine signaling C. Juxtacrine signaling D. Competence

A. Morphogen gradient

Which of the following cues is best suited for regulation cell-contact dependent signaling? A. NOTCH B. ERK 1/2 C. WNT D. BMP

A. NOTCH

You are growing two types of cells, mesenchymal cells and epidermal cells, in two different dishes to study cell-cell interactions. If you take the liquid medium only (no cells) from the mesenchymal cell dish and place some of it into the epidermal cell dish, the epidermal cells begin to proliferate and change shape. What type of cell-cell interaction is taking place? A. Paracrine signaling B. Autocrine signaling C. Juxtacrine signaling D. Endocrine signaling

A. Paracrine signaling

In the ovary, oocytes are held at diplotene of meiosis I at birth. How is the diplotene block released? A. Progesterone activates c-Mos, which phosphorylates maturation promotion factor (MPF). B. A Ca2+ influx induces the activity of calmodulin, which induces calmodulin and it phosphorylates maturation promotion factor (MPF) C. Calmodulin dependent kinase II (CamKII) and calpain are activated by progesterone and they degrade cytostatic factor (CSF). D. Progesterone activates c-Mos, which phosphorylates cytostatic factor (CSF).

A. Progesterone activates c-Mos, which phosphorylates maturation promotion factor (MPF).

Which of the following techniques could be used to "silence" MyoD gene expression in mouse cells? A. RNA interference (RNAi) B. In situ hybridization (ISH) C. RT-PCR D. transgenic expressing MyoD

A. RNA interference (RNAi)

Cells are grown in culture in a dish with 2 chambers, upper and lower. In between the chambers is a membrane that allows for small molecules to pass between the chambers. After several days in culture the upper cells stop dividing and become cuboidal in shape and the lower cells increase their proliferation rate. This is an example of which of the following? A. Reciprocal induction B. Lack of competence C. Permissive induction D. Lack of inducer

A. Reciprocal induction

In order to block Shh signaling, which of the following interventions would be most effective? A. Treatment with cyclopamine, a Smoothened inhibitor B. Application of U0126, a MEK1/2 inhibitor C. Overexpression of an siRNA to Frizzled D. Microinjection of a construct encoding Delta

A. Treatment with cyclopamine, a Smoothened inhibitor

You have made a trans gene expressing the LacZ reporter gene. Where will this trans gene integrate into the genome? A. a random chromosomal location B. at the LacZ locus C. it will not integrate into the genome D. on a plasmid

A. a random chromosomal location

You are able to fluorescently label a cell in a chick embryo and watch it over the course of a few days. On the first day, the cell looks like most others around it, but over time, you notice that it fuses with other cells and elongates to form long multinucleate tubes. What best describes the process you have observed? A. differentiation B. determination C. specification D. proliferation

A. differentiation

Which of the following is the end result of spermatogenesis? A. haploid round spermatid B. mature spermatozoa C. spermatogonia D. type B spermatogonium

A. haploid round spermatid

The following figure shows gene expression of MyoD, an important transcription factor involved in myogenesis, at various embryonic mouse stages as detected by an antisense mRNA probe. Which of the following techniques was used to generate these data? A. in situ hybridization (ISH) B. western blot C. RT-PCR D. transgenic mouse expression MoyD

A. in situ hybridization

You are studying the gene Herculin and want to know if a specific enhancer sequence regulates skeletal muscle specific expression of this gene. How would you do this? A. make a transgenic mouse that expresses Green Fluorescent Protein (GFP) under the control of the Herculin enhancer B. make an antisense RNA probe of the enhancer for in situ hybridization C. clone the Herculin coding sequence into a plasmid D. isolate RNA from skeletal muscle for QRT-PCR

A. make a transgenic mouse that expresses Green Fluorescent Protein (GFP) under the control of the Herculin enhancer

Which of the following accurately describes the product of meiosis in female mammals? A. one haploid oocyte and 1-3 polar bodies B. one diploid oocyte and 1-3 polar bodies C. four diploid oocytes D. four haploid oocytes

A. one haploid oocyte and 1-3 polar bodies

You would like to generate a transgenic mouse to identify cells that express Shh during development. Here is the map for the mouse Shh gene from ENSEMBL. A colleague sent you a plasmid containing the entire ~12 kilobase (kb) region below.Which of the regions (A-D) would you attempt to 'excise' from the vector to use in your transgene meant to drive the expression of EGFP?

A. this is where the promoter is located, which you could ligate to a GFP sequence in your transgene. This transgene could then 'report' which cells express Shh during development by expressing GFP.

In the mammalian embryo, which structure is essential to set up the anterior-posterior axis? A.Anterior visceral endoderm B.Inner cell mass C.Node D.Sperm entry site E.Primitive streak

A.Anterior visceral endoderm

In the ovary, oocytes are held at diplotene of meiosis I at birth. How is the diplotene block released? A.Progesterone activates c-Mos, which phosphorylates maturation promotion factor (MPF). B.A Ca2+ influx induces the activity of calmodulin, which induces calmodulin and it phosphorylates maturation promotion factor (MPF) C.Calmodulin dependent kinase II (CamKII) and calpain are activated by progesterone and they degrade cytostatic factor (CSF). D.Progesterone activates c-Mos, which phosphorylates cytostatic factor (CSF).

A.Progesterone activates c-Mos, which phosphorylates maturation promotion factor (MPF).

When do mammalian oocytes complete meiosis? During folliculogenesis, before ovulation After ovulation, before fertilization After fertilization Before birth

After fertilization

In this diagram of the developing gastrula, which of the images most closely reflects the orientation of the future embryo at this stage?

B

The primitive streak plays a key role in gastrulation. Where is the primitive streak located in the 24 hr old chick embryo below?

B

Which part of the shown transgene contains the promoter/enhancer?

B

At ovulation, mammalian oocytes are at metaphase II. How is the metaphase block released and meiosis completed? A. A Ca2+ influx induces the activity of calmodulin, which induces Calmodulin dependent kinase II (CamKII) and it phosphorylates maturation promotion factor (MPF). B. A Ca2+ influx activates Calmodulin which activates CamKII and calpain. These enzymes then degrade cytostatic factor (CSF). C. Progesterone activates c-Mos, which phosphorylates maturation promotion factor (MPF). D. Progesterone activates c-Mos, which phosphorylates cytostatic factor (CSF).

B. A Ca2+ influx activates Calmodulin which activates CamKII and calpain. These enzymes then degrade cytostatic factor (CSF).

Which of the modifications described below would increase Gli mediated transcription in the limb bud? A. Generate a Patchedloxp/loxp:Fgf8-Cre mouse. B. Application of Shh-coated beads to the limb bud. C. Introduce a germline mutation that decreases RTK activity. D. Treatment of developing embryos with cyclopamine, a pharmacological inhibitor of Smoothened.

B. Application of Shh-coated beads to the limb bud.

The epididymis is the sperm storage organ in mammals. Sperm that is aspirated by a needle from the epididymis is fully motile and able to fertilize an egg. A.True B.False

B. False

You have made a targeting vector to knock out Gene X. What is the next step? A. Electroporate the vector into embryonic stem cells (ES) and select for those that are correctly targeted. B. Inject the vector into embryonic stem cells (ES) and implant them into a mouse. C. Inject the vector into a fertilized oocyte and harvest embryos. D. Stain for LacZ expression in embryos.

B. Inject the vector into embryonic stem cells (ES) and implant them into a mouse.

If you harvest spermatozoa from the epididymis for IVF treatment in infertile men what must happen before they can fertilize an egg? A. interaction with zona pellucida proteins B. capacitation C. acrosome reaction D. binding to Izumo

B. capacitation

Which of the following is necessary to create a knockout mouse? A. fertilized oocytes B. embryonic stem cells C. germ cells

B. embryonic stem cells

You are making a transgene, where do you predict it will integrate into the genome? A.At a specific gene locus. B.A random chromosomal location C.On a plasmid D.It does not integrate.

B.A random chromosomal location

Which of the following statements correctly interprets the data from the experiment depicted? A.There is no species specificity for bindin. B.Bindin binds in a species specific manner to eggs C.Bindin does not bind to eggs D.Eggs block bindin activity.

B.Bindin binds in a species specific manner to eggs

Which of the following statements is FALSE? A.Cell fates are reversible after specification. B.During autonomous specification, cells require communication with surrounding cells for commitment to a particular cell fate. C.Differentiation involves changes in gene expression, morphology, and function. D.Cell fates are irreversible after determination.

B.During autonomous specification, cells require communication with surrounding cells for commitment to a particular cell fate.

Which cells undergo meiosis? A.Embryonic stem cells B.Germ cells C.Somatic cells

B.Germ cells

SCF secretion from the Sertoli cells to spermatic cells is an example of _________ signaling. Fill in the blank. A.Juxtacrine B.Paracrine C.Autocrine D.Endocrine

B.Paracrine

In the figure below, the phenotypes of myostatin (Mstn) mutations are shown. You can conclude that... A.alternate splicing of myostatin is required for myogenesis B.myostatin inhibits myogenesis C.myostatin promotes myogenesis

B.myostatin inhibits myogenesis

A 25 year-old man visits a urologist to investigate why he is unable to have children. Semen analysis revealed round nonmotile sperm with a DNA content at n. The patient's infertility is most likely due to a functional defect in which of the following? A.mitosis B.spermiogenesis C.Meiosis D.Leydig cells

B.spermiogenesis

If you have a defect that blocks release of gonadotropin releasing hormone (GnRH) from the pituitary, which of the following statements would be true? Only spermatogenesis would be disrupted by the loss of FSH. Only folliculogenesis would be disrupted by the loss of FSH. Both folliculogenesis and spermatogenesis would be disrupted. There would be no disruption of either spermatogenesis or folliculogenesis

Both folliculogenesis and spermatogenesis would be disrupted.

Which part of the shown transgene is the "reporter" part of gene?

C

Follicle stimulating hormone (FSH) stimulate the ____________ to _____________ and secrete _____________. Fill in the blanks. A. Granulosa cells, proliferate, luteinizing hormone B. Theca cells, apoptosis, estrogen C. Granulosa cells, proliferate, estrogen D. Oocytes, proliferate, progesterone

C. Granulosa cells, proliferate, estrogen

Kartegener's triad is a genetic disorder in which patients lack dynein, the motor protein of cilia and flagella. Which of the following most likely describes the spermatozoa of men with this disorder? A.Haploid motile sperm B.Diploid motile sperm C.Haploid nonmotile sperm D.Diploid nonmotile sperm

C. Haploid nonmotile sperm

Signaling between endosteal osteoblasts and hematopoietic stem cells (HSC) in the niche are necessary for which of the following? A. Differentiation of myeloid cells only. B. T and B Cell differentiation C. Maintenance of HSC potency and proliferation D. Angioblast specification

C. Maintenance of HSC potency and proliferation

In response to detection of RESACT in water, which of the following will occur? A. It will cause cortical granule release B. It will induce a change in the oocyte membrane potential. C. Spermatozoa will increase speed and swim directly towards the oocyte D. Spermatozoa will undergo capacitation.

C. Spermatozoa will increase speed and swim directly towards the oocyte

The following is a diagram from Ensembl of the MC1R gene that regulates red hair color. Where is the translational start site?

C. The AUG (start codon) is in exon 2

You have a female patient that has unexplained infertility. Her male partner has normal spermatozoa. During in vitro fertilization it is noted that the spermatozoa do not bind to and fertilize her eggs. What is the probable defect? A. The is no slow block to polyspermy B. There is no fast block to polyspermy C. There is a defect in ZP2 D. There is a defect in Bindin

C. There is a defect in ZP2

You have found a compound that you suspect is a chemoattractant for sperm. If so it should_________. Fill in the blank. A. decrease sperm mitochondrial respiration B. induce random sperm movement C.bind to sperm D. bind to eggs

C. bind to sperm

The engineered CRISPR/Cas9 system is a pioneering approach for genome editing. Which of the following components is required for targeting Cas9 to specific sites in the genome. A. loxp sites with the specific gene of interest B. CRISPR regions in the Pax6 gene C. co-expressing a guide RNA complementary to the targeted sequence D. injecting a fertilized zygote with Cas9 bound to a transcription factor that normally binds the targeted region

C. co-expressing a guide RNA complementary to the targeted sequence

The secretion of FSH from the pituitary is an example of what type of signaling? A.Juxtacrine B.Paracrine C.Endocrine D.Autocrine

C.Endocrine -signals from a distance through the blood stream

The diagram shows a nematode embryo at the four cell stage. The EMS cell normally divides and gives rise to cells that will form the mesoderm and endoderm. Killing the P2 cells leads to the disruption of EMS cell differentiation, which of the following best describes the process taking place? (diagram shows normally EMS cells become mesoderm and endoderm, then without P2 differentiation is disrupted) A.autonomous specification of the EMS cell B.autonomous specification of the P2 cell C.conditional specification of the EMS cell D.conditional specification of the P2 cell

C.conditional specification of the EMS cell

All the cells of the embryo proper (all the cells in your body now) derive from which of the following cells? A.hypoblast B.trophoblast C.epiblast

C.epiblast

Which of the following cell types is formed from epiblast cells that migrate through the primitive streak? A.ectoderm B.primary hypoblast C.mesoderm

C.mesoderm CORRECT, the mesoderm forms from the epiblast cells migrating through the primitive streak.

You have raised the [morphogen] produced at the source, but the [sink] and [threshold] for responder cell fate remains unchanged. What do you expect would happen to the pattern of white/gray/black cells?

D

In this diagram, you see that culturing red cells near green cells leads to a proliferative response in the green cells. Based on your intervention in Experiments 1 & 2, which is the most accurate conclusion about this interaction? A.Red cells induce proliferation via juxtracrine signaling. B.Green cells respond to a paracrine molecule larger than 1 micron. C.Red cells secrete a paracrine molecule that induces death in green cells. D.Green cells proliferate in response to a paracrine molecule derived from red cells.

D. Green cells proliferate in response to a paracrine molecule derived from red cells.

A young man was given a chemotherapy drug that caused Sertoli cells to die. Which of the following is most likely to result? A. Normal spermatogenesis, defective spermiogenesis B. Low testosterone levels resulting in reduced spermatogenesis. C. Defective spermatogenesis, normal spermiogenesis D. Loss of all spermatogenic cells

D. Loss of all spermatogenic cells

One of the earliest events that distinguishes meiosis from mitosis occurs in prophase I and involves ______ . Fill in the blank with the best answer. A. condensation of chromosomes B. Breakdown of the nuclear membrane C. chromosomes lining up at the metaphase plate D. formation of the synaptonemal complex

D. formation of the synaptonemal complex

An oogonium enters ____________ embryonically and is blocked at _____________ until sexual maturity. Fill in the blanks. A. mitosis: metaphase II B. mitosis: diplotene I C. meiosis : metaphase II D. meiosis: diplotene I

D. meiosis: diplotene I

Which element of a trans gene helps to stabilize the mRNA, thus enhancing trans gene expression? A. promoter B. exon 1 C. stop codon D. poly A tail

D. poly A tail

In this diagram of the Notch signaling pathway, __________ is the molecule on the inducing cell that binds to the Notch1 receptor on the responding cell. This is an example of _________ signaling. A.Lfng, juxtacrine B.Dll3, juxtacrine C.Dll1, paracrine D.Dll1, juxtacrine

D.Dll1, juxtacrine

What is the outcome of mammalian meiosis? A.Always four haploid germ cells. B.Always four diploid germ cells. C.One haploid germ cell. D.It depends on the sex of the germ cell.

D.It depends on the sex of the germ cell.

The following pathway diagram shows juxtracrine signaling. The ______________ ligand is on the inducing cell and _____________ is the receptor on the responding cell.

Delta; Notch

Which of the following is the correct order of developmental steps leading to a specialized cell type? A. determination, differentiation, specification B. differentiation, specification, determination C. determination, specification, differentiation D. differentiation, determination, specification E. specification, determination, differentiation

E. specification, determination, differentiation

Follicle stimulating hormone (FSH) stimulate the ____________ to _____________ and secrete _____________. Fill in the blanks. Granulosa cells, proliferate, luteinizing hormone Theca cells, apoptosis, estrogen Granulosa cells, proliferate, estrogen Oocytes, proliferate, progesterone

Granulosa cells, proliferate, estrogen

The following figure shows gene expression of MyoD, an important transcription factor involved in myogenesis, at various embryonic mouse stages as detected by an antisense mRNA probe. Which of the following techniques was used to generate these data? In situ hybridization (ISH) Western blot RT-PCR Transgenic mouse expressing MyoD

In situ hybridization (ISH)

Which of the following manipulations would be most effective at REDUCING the number of cells in the "gray" domain. Increasing the concentration threshold for "black" cells.. Decreasing the concentration threshold for "gray" cells Increasing the morphogen concentration at the source by 20% Increasing the concentration threshold for "gray " cells

Increasing the concentration threshold for "gray " cells

What will be the result of thymidine kinase gene (TK) being incorporated into an ES cell's genome? It will make cells resistant to neomycin. It will make cells resistant to Gancyclovir. It will make cells sensitive to Gancyclovir. It will make cells sensitive to neomycin.

It will make cells sensitive to Gancyclovir.

A young man was given a chemotherapy drug that caused Sertoli cells to die. Which of the following is most likely to result? Normal spermatogenesis, defective spermiogenesis Low testosterone levels resulting in reduced spermatogenesis. Defective spermatogenesis, normal spermiogenesis Loss of all spermatogenic cells

Loss of all spermatogenic cells

You think you have determined where the promoter/enhancer region for the gene Sox9 is found. You want to find all of the tissues that express the Sox9 gene from this promoter/enhancer during embryogenesis. Which of the following would be the best method to use to determine this? Use ISH for Sox10 in Sox9-/- embryo Examine which proteins are expressed by histology Clone Sox9 into a plasmid Make a transgene expressing GFP under control of the Sox9 promoter/enhancer

Make a transgene expressing GFP under control of the Sox9 promoter/enhancer

Which of the following techniques could be used to "silence" MyoD gene expression in mouse cells? RNA interference (RNAi) In situ hybridization (ISH) RT-PCR Transgenic expressing MyoD

RNA interference (RNAi)

A mouse is given the drug busulfan, which kills spermatogonial cells. One month later, healthy spermatogonia are transplanted into the seminiferous tubules of this mouse. What will happen? Nothing Spermatogenesis will be restored. Testosterone levels will increase. Estrogen levels will increase.

Spermatogenesis will be restored.

In order to breed a gene X chimeric mouse to create a homozygous gene X knockout mouse, the mutated embryonic stem (ES) cells that were injected into the inner cell mass of a blastocyst must contribute to what part of the chimeric embryo? The germline cells All embryonic cells Trophoblast cells Only cells that express gene X. Only cells that do not express gene X.

The germline cells

You are making a knockout mouse, after neomycin (positive) selection you treat the surviving cells with gancyclovir (negative selection) and more cells die. What does cell death after gancyclovir treatment indicate? The targeting vector randomly inserted into the genome The targeting vector inserted into the genome by homologous recombination The targeting vector did not insert into the genome

The targeting vector randomly inserted into the genome

Which of the following describes some of the key attributes of embryonic stem cells that made these cells useful for the creation of knockout mice? They are pluripotent and can be cultured indefinitely in an undifferentiated state. They are monopotent and can be cultured indefinitely in an undifferentiated state. They are pluripotent and cannot be cultured indefinitely. They are monopotent and cannot be cultured indefinitely.

They are pluripotent and can be cultured indefinitely in an undifferentiated state.

ES cells were important for the development of molecular genetic techniques to manipulate the mouse genome. What is the most important attribute of these stem cells? They are monopotent They are pluripotent. They can only become the trophectoderm. They cannot differentiate.

They are pluripotent.

In order to block Shh signaling, which of the following interventions would be most effective? Treatment with cyclopamine, a Smoothened inhibitor Application of U0126, a MEK1/2 inhibitor Overexpression of an siRNA to Frizzled Microinjection of a construct encoding Delta

Treatment with cyclopamine, a Smoothened inhibitor

If you harvest spermatozoa from the epididymis for IVF treatment in infertile men what must happen before they can fertilize an egg? interaction with zona pellucida proteins capacitation acrosome reaction binding to Izumo

capacitation

Which of the following represent a slow block to polyspermy employed by eggs? cholesterol synthesis bindin proteolysis cortical granule exocytosis react secretion

cortical granule exocytosis

What is the genomic signal that tells the cell to start transcription? a)AUG start codon b)enhancer c)polyA signal d)promoter e)splice acceptor

d)promoter- CORRECT, the promoter sequences are required to initiate transcription

Which of the following is an accurate statement about enhancers? a)5'-3' orientation is important for function b)they are located 5' of the promoter c)they are within 10 kb of the coding sequences d)they regulate translational efficiency e)transcription factors bind to them

e)transcription factors bind to them-CORRECT, they are the sites of transcription factor binding

You grow mesenchymal cells in Dish A and epidermal cells in Dish B. If you take the liquid medium only (containing no cells) from Dish A and put it into the liquid medium covering the epidermal cells in Dish B, you notice that it causes the epidermal cells to round up and thicken. What developmental concept does this example best describe? autonomous specification in epithelial cells induction of epithelial cells by juxtacrine signaling from mesenchymal cells induction of epithelial cells by paracrine signaling from mesenchymal cells induction of mesenchymal cells by juxtacrine signaling from epithelial cells induction of mesenchymal cells by paracrine signaling from epithelial cells

induction of epithelial cells by paracrine signaling from mesenchymal cells

An oogonium enters ____________ embryonically and is blocked at _____________ until sexual maturity. Fill in the blanks. mitosis : metaphase II mitosis: diplotene I meiosis : metaphase II meiosis: diplotene I

meiosis: diplotene I

When making a transgenic mouse we take advantage of which of the following processes to insert the transgene into the genome? homologous recombination nonhomologous recombination RNA splicing Start codons

nonhomologous recombination

.Which of the following accurately describes the product of meiosis in female mammals? one haploid oocyte and 1-3 polar bodies one diploid oocyte and 1-3 polar bodies four diploid oocytes four haploid oocytes

one haploid oocyte and 1-3 polar bodies

Pick the answer that BEST describes the potential of embryonic stem cells (ES cells). Pluripotential Monopotential Multipotential Fully differentiated

pluripotential

Which element of a transgene helps to stabilize the mRNA, thus enhancing transgene expression? A. promoter B. exon 1 C. stop codon D. polyA tail

polyA tail

The acrosome reaction __________. Pick the best answer to finish the statement. releases enzymes necessary for penetrating the zona pellucida is necessary to block polyspermy removes ZP3 from the spermatozoa increases the mitochondrial respiration rate of spermatozoa

releases enzymes necessary for penetrating the zona pellucida

You have frozen a sample of tissue from the developing hindlimb and would like to analyze the levels of FGF8 protein. Which of the following would be the best technique? in situ hybridization western blotting transcriptomics siRNA

western blotting