Genetics and Developmental Biology

Homework Problem!

Homework Problem!

This is for my developmental biology class...

Fugu is a vertebrate like humans, with many of the same complex structures and organ systems. However, unlike humans the size of the Fugu genome is a mere 400 Mb compared to the 3000 Mb of huma

barry   3922   3 Replies

ThePsychic

Embyronic Stem Cells Q.

Embyronic Stem Cells Q.

As the first step in generating a ? -catenin knock-out mouse, you have used ES cells from a black mouse strain and selected for cells in which an appropriate transfected construct has undergone homologous recombination at the ?-catenin locus.  Y

ThePsychic   1529   2 Replies

ThePsychic

In human embryo, does the middle ear have an ectodermal or mesodermal origin?

In human embryo, does the middle ear have an ectodermal or mesodermal origin?

in human embryo, does the middle ear have an ectodermal or mesodermal origin ?

also if anyone has links to websites with videos or detailed pictures of the different steps in echinoderms, amphibians, birds and mammals embryogenesis plz po

karim89   3097   4 Replies

bio_man

symbiotic relationship

symbiotic relationship

Describe the types of symbiotic relationships seen between humans and bacteria. Give specific example for each type of relationship.

Chris   4203   1 Reply

bio_man

Flies that expressed hunchback

Flies that expressed hunchback

Briefly describe the strains that were used to generate the flies that expressed hunchback (hb) in the anterior at a time when it is normally downregulated (during cellularization).  Don’t forget to mention how they targeted the hb expression.

ppk   1241   1 Reply

bio_man

Myosin heavy chain

Myosin heavy chain

In an animal that has only a single myosin heavy chain (MHC) gene, striated skeletal muscle contains an isoform of MHC that is not found in smooth muscle, which contains a different isoform not found in skeletal muscle. (Isoforms: very similar protei

ppk   1329   1 Reply

bio_man

Steroid hormone testosterone

Steroid hormone testosterone

The steroid hormone testosterone controls almost all aspects of male development in mammals.  We know there is only a single type of testosterone receptor in all the cells that respond to it, because mutant XY individuals who lack the receptor a

ppk   1229   1 Reply

bio_man

Drosophila patterning

Drosophila patterning

In experiments on Drosophila patterning, you treat fertilized eggs with a drug that completely blocks RNA polymerase II, which is required for all mRNA synthesis.

Explain briefly if and how you would expect this treatment to affect the pr

ppk   1051   1 Reply

bio_man

Gene Therapy Department Question

Gene Therapy Department Question

It is 2011, and you are doing your internship in the Gene Therapy Department of a well known medical school.  Techniques for gene therapy are now well established.  Hilary Clinton, midway through her first term as president, and her adminis

ppk   1016   1 Reply

bio_man

Mammalian ES

Mammalian ES

Mammalian ES cells grown in culture on a “feeder” layer of fibroblasts can be made to differentiate into several types of differentiated cells by treatment with appropriate growth factors, but the feeder layer is essential.  What are two possibl

ppk   1019   1 Reply

bio_man

autonomous or non-autonomous cell

autonomous or non-autonomous cell

Suppose you were to carry out a mosaic analysis of the EGFR homolog let-23, using a homozygous let-23(-) strain that carries a small free duplication including the let-23(+) gene.  The duplication is occasionally lost during somatic development,

ppk   1664   1 Reply

bio_man

Analysis of a human female fetus by amniocentesis

Analysis of a human female fetus by amniocentesis

Analysis of a human female fetus by amniocentesis indicates that the baby will have a normal XX karyotype but is heterozygous for a mutation that inactivates the Xist promoter.  Explain how dosage compensation will be affected by this mutation.&

ppk   1592   2 Replies

ppk

Briefly describe an experiment you could do to provide convincing evidence

Briefly describe an experiment you could do to provide convincing evidence

Briefly describe an experiment you could do to provide convincing evidence that a specific gene called Dax-1, found on the X chromosome, is required for female primary sex determination. Also include a logical explanation for why males, who have a co

ppk   1378   1 Reply

bio_man

Pufferfish (FUGU)

Pufferfish (FUGU)

The pufferfish is, obviously, a fish, and a member of the vertebrate class of animals, as we are.  The complexity of the human genome is about 3,000 megabases (Mb), while that of the pufferfish is about 400 Mb.  Which two of the following r

ppk   1150   5 Replies

bio_man

Blastula stage

Blastula stage

All non-mammalian embryos go through a blastula stage with a fluid-filled blastocoel.  What function/s does/do the blastocoel serve in development of the frog embryo? 

ppk   1316   2 Replies

ppk

KFC franchise

KFC franchise

As the owner of a KFC franchise, you want to raise chickens that have an extra set of wings.  How would you do it?  Be brief. 

ppk   3090   3 Replies

kong

Sea urchin Embryology Lab

Sea urchin Embryology Lab

1) What would happen if the sperm could not get into the egg ? (sea urchin)

flower555   2032   1 Reply

bio_man

Totipotency

Totipotency

Many animal species share these similarities in early development. Yet, the stage at which the individual cells of the embryo lose their totipotency can vary considerably among these species.

a. What does it mean to say that a cell is toti

ppk   2904   1 Reply

bio_man

A girl begins to develop breasts and pubic hair at the age of four

A girl begins to develop breasts and pubic hair at the age of four

A girl begins to develop breasts and pubic hair at the age of four. Given these symptoms, her physician orders a CT scan (imaging procedure) to look for an endocrine tumor. Which organ would he most likely not investigate as the cause?
Explain y

ppk   2294   1 Reply

duddy

Spemann and Mangold Blastopore Experiment

Spemann and Mangold Blastopore Experiment

In a now classic experiment, Spemann and Mangold took cells from the dorsal lip of the blastopore from one frog embryo (the donor) and transplanted them to an area opposite the dorsal lip in another frog embryo (the host). As a result, the host embry

ppk   2221   1 Reply

duddy

Vaccination & Hormones

Vaccination & Hormones

Assume that women can be vaccinated against the following hormones. Each vaccine is designed to completely neutralize the target hormone’s activity. Which vaccine(s) would prevent pregnancy? Explain your answers.

A = Would prevent pregnanc

ppk   2767   1 Reply

duddy

Neuron function in Squids

Neuron function in Squids

Much of our understanding of neuron function was based on studies of the squid giant axon. Squid move through the water by contracting the muscles of the mantle. This compresses water inside the mantle that is forced out the siphon. Squid can change

ppk   5716   1 Reply

duddy

The structure of the Drosophila gene called Tinman is similar to a gene in human

The structure of the Drosophila gene called Tinman is similar to a gene in human

The structure of the Drosophila gene called Tinman is similar to a gene in humans that also

A) filters lymphatic fluid.
B) promotes ear development.
C) specifies the location of the heart.
D) specifies limb elongation points

ppk   1944   1 Reply

bio_man

The endoderm was probably stained with

The endoderm was probably stained with

The endoderm was probably stained with     
A) yellow and green colors.
B) purple and red colors.
C) blue and yellow colors.
D) red and yellow colors.
E) green and purple colors.

ppk   1692   1 Reply

bio_man

Gases are exchanged in a mammalian embryo in the

Gases are exchanged in a mammalian embryo in the

Gases are exchanged in a mammalian embryo in the     
A) hypoblast.      B) amnion.      C) yolk sac.      D) trophoblast.      E) chorion.

ppk   3141   1 Reply

hysteric

When you slice up a pie that contains a swirled mixture of chocolate and vanilla

When you slice up a pie that contains a swirled mixture of chocolate and vanilla

 When you slice up a pie that contains a swirled mixture of chocolate and vanilla filling, you notice that some slices have more chocolate than vanilla and that other slices have more vanilla than chocolate. This uneven distribution of chocolate and

ppk   1542   1 Reply

bio_man

Which of the following is an adult organism that has fewer than 1,000 cells?

Which of the following is an adult organism that has fewer than 1,000 cells?

Which of the following is an adult organism that has fewer than 1,000 cells?     
A) chickens, Gallus domesticus
B) nematodes, Caenorhabditis elegans
C) humans, Homo sapiens
D) fruit flies, Drosophila melanogaster

ppk   1879   1 Reply

bio_man

In placental mammals, the yolk sac

In placental mammals, the yolk sac

 In placental mammals, the yolk sac   
A) differentiates into the placenta.
B) transfers nutrients from the yolk to the embryo.
C) becomes a fluid-filled sac that surrounds and protects the embryo.
D) produces blood cel

ppk   3515   1 Reply

biolove

The yolk of the frog egg

The yolk of the frog egg

The yolk of the frog egg     
A) is concentrated at the animal pole.
B) impedes the formation of a primitive streak.
C) prevents gastrulation.
D) supports the higher rate of cleavage at the animal pole compared to

ppk   2022   1 Reply

biolove

If an amphibian zygote is manipulated so that the first cleavage plane fails to

If an amphibian zygote is manipulated so that the first cleavage plane fails to

If an amphibian zygote is manipulated so that the first cleavage plane fails to divide the gray crescent, then   
A) both daughter cells will die immediately.
B) both daughter cells will develop normally because amphibians are totipote

ppk   1928   1 Reply

bio_man

In humans, identical twins are possible because

In humans, identical twins are possible because

In humans, identical twins are possible because     
A) of interactions between extraembryonic cells and the zygote nucleus.
B) the gray crescent divides the dorsal-ventral axis into new cells.
C) of convergent extension.

ppk   1570   1 Reply

bio_man

In frogs, formation of the eye lens is induced by chemical signals from

In frogs, formation of the eye lens is induced by chemical signals from

 In frogs, formation of the eye lens is induced by chemical signals from     
A) an outgrowth of the developing brain.
B) cells that will become the neural plate.
C) both cells that will become the neural plate and an o

ppk   2416   1 Reply

bio_man

From earliest to latest, the overall sequence of early development proceeds in w

From earliest to latest, the overall sequence of early development proceeds in w

From earliest to latest, the overall sequence of early development proceeds in which of the following sequences?   

A) cleavage ? gastrulation ? organogenesis
B) gastrulation ? blastulation ? neurulation
C) preformation ? mo

ppk   3099   1 Reply

duddy

The earliest developmental stage among these choices is

The earliest developmental stage among these choices is

 The earliest developmental stage among these choices is     
A) germ layers.
B) invagination.
C) gastrulation.
D) morula.
E) blastopore.

ppk   2449   1 Reply

duddy

Among these choices, the largest cell involved in frog reproduction is

Among these choices, the largest cell involved in frog reproduction is

Among these choices, the largest cell involved in frog reproduction is     
A) the spermatozoon.
B) a blastomere in the vegetal pole.
C) one of the products of the first cleavage.
D) the ovum.
E) a blastomere

ppk   2106   1 Reply

duddy

The embryonic precursor to the human spinal cord is the

The embryonic precursor to the human spinal cord is the

 The embryonic precursor to the human spinal cord is the   
A) notochord.
B) neural tube.
C) archenteron.
D) set of bilateral somites.
E) mesoderm.

ppk   2933   1 Reply

sarah!

A primitive streak forms during the early embryonic development of

A primitive streak forms during the early embryonic development of

A primitive streak forms during the early embryonic development of     
A) humans, but not birds or frogs.
B) humans and birds, but not frogs.
C) frogs, but not birds or humans.
D) birds, but not frogs or humans.
E)

ppk   2376   1 Reply

sarah!

Assume that successful reproduction in a rare salamander species, wherein all in

Assume that successful reproduction in a rare salamander species, wherein all in

Assume that successful reproduction in a rare salamander species, wherein all individuals are females, relies on those females having access to sperm from males of another species but that the resulting embryos show no signs of a genetic contribution

ppk   2365   1 Reply

duddy

In an egg cell treated with EDTA, a chemical that binds calcium and magnesium io

In an egg cell treated with EDTA, a chemical that binds calcium and magnesium io

In an egg cell treated with EDTA, a chemical that binds calcium and magnesium ions, the     
A) fertilization envelope would not be formed.
B) zygote would not contain maternal and paternal chromosomes.
C) acrosomal reaction

ppk   3256   1 Reply

duddy

In an egg cell treated with EDTA, a chemical that binds calcium and magnesi

In an egg cell treated with EDTA, a chemical that binds calcium and magnesi

In an egg cell treated with EDTA, a chemical that binds calcium and magnesium ions,      
A) the fast block to polyspermy would not occur.
B) the fertilization envelope would not form.
C) the fusion of sperm and egg nucl

ppk   2400   1 Reply

duddy