Bio Test #4

For pattern formation to occur, the cells in the developing embryo must

"know" their position in the embryo.

The Galapagos finches are believed to have evolved from __________ mainland species.

1

Which of the following would be best as a probe in a Southern blot? 1) A single stranded fragment complementary to the target sequence. 2) A single stranded fragment identical to the target sequence. 3) A double stranded fragment complementary to the target sequence. 4) A double stranded fragment identical to the target sequence.

1) A single stranded fragment complementary to the target sequence.

Several kinds of genetic changes can convert a proto-oncogene into an oncogene. 3 of the most typical are called what?

1)mutation in coding sequence 2)Gene Amplification 3)chromosome rearrangement

How many species of Galapagos finch are there?

13

Which of the following is an example of reverse genetics? 1) identifying a protein-protein interaction by a yeast two-hybrid screen 2) mutating a cloned gene and substituting the mutant copy for the wild-type copy in an organism to assess its function 3) finding a mouse gene can direct eye formation in Drosophila 4) observing a phenotype and isolating the gene that produces that phenotype 5) isolating clones from a library using hybridization of a radiolabeled probe

2) mutating a cloned gene and substituting the mutant copy for the wild-type copy in an organism to assess its function

One of the most useful methods for identifying a specific DNA sequence is 1) magnetic resonance imaging. 2) the Southern blot. 3) the Eastern blot. 4) thin-layer chromatography. 5) the Western blot.

2) the Southern blot

A powerful way to identify an individual using a particular gene as a marker is the analysis of 1) PCRs. 2) transgenic animals. 3) Western blots. 4) RFLPs. 5) Northern blots.

4) RFLPs.

A DNA library is?

A collection of DNA fragments representing the entire genome of an organism.

What is a Ti plasmid?

A vector that can transfer recombinant genes into plant genomes.

In induction, an inducing tissue directs the target tissue to develop along a particular fate path. A) True B) False

A) True

What is the ultimate source of genetic variability? A) mutation B) migration C) genetic drift D) nonrandom mating E) selection

A) mutation

The initial dorsal-ventral orientation of vertebrate embryos is determined by A) the point of entry of the sperm B) gravity C) the point of contact with the uterus D) genetic differences in the cells

A) the point of entry of the sperm

Internal structures of vertebrates form from the _______________ pole of the zygote. A) vegetal B) endodermal C) mesodermal D) animal E) ectodermal

A) vegetal

What % of colon tumors have mutations in the APC gene?

About 60%

What would be the likely result of the mutation of the bcl-2 gene on the level of apoptosis?

An increase in apoptosis.

Differentiation of embryonic cells into adult structures results in the loss of DNA for genes that are no longer expressed in differentiated tissues. A) True B) False

B) False

Homeobox motifs have been found in animal cell DNA but not in plant cell DNA. A) True B) False

B) False

At about the 16-cell stage in vertebrate development, a central cavity expands and forms a hollow ball of cells called a(n): A) neurula B) blastula C) ectoderm D) gastrula E) endoderm

B) blastula

Which of the following factors is most likely to contribute to gene flow between populations? A) random mating B) migration C) mutation D) genetic drift E) inbreeding

B) migration

In relation to natural selection, evolution is the A) process B) outcome C) mechanism D) purpose

B) outcome

Which of the following is not an example of a vestigial structure in humans? A) coccyx B) pelvis C) appendix D) all of the above are vestigial

B) pelvis

Skeletal muscles, blood cells, and gametes are derived from cells from the A) neural crests B) somites C) endoderm D) animal pole

B) somites

If a cell has committed to a particular fate it is said to be: A) pluripotent B) totipotent C) determined D) differentiated E) mosaic

C) determined

The occurrence of large or small beak sizes among seed crackers in the absence of medium-sized beaks is an example of A) directional selection B) stabilizing selection C) disruptive selection D) none of the above

C) disruptive selection

The movement of new genes into a population as a result of migration or hybridization is called A) founder principle B) selection C) gene flow D) bottleneck effect E) adaptation

C) gene flow

The random loss of alleles in a population is called A) mutation B) selection C) genetic drift D) electrophoresis E) gene flow

C) genetic drift

In fungi, maturation is primarily a process of A) specialization B) mobilization C) growth D) gastrulation

C) growth

Even though sickle-cell anemia is usually fatal to homozygous individuals, the disease persists because: A) gene therapy has alleviated the condition B) the disease is carried on a dominant allele C) individuals with one allele for sickle-cell anemia are resistant to malaria D) a combination of all of the above E) none of the above

C) individuals with one allele for sickle-cell anemia are resistant to malaria

Development of syncytial blastoderm is characteristic of A) frogs B) birds C) insects D) salamanders E) starfish

C) insects

In gastrulation, cells at the vegetal pole move by using A) parapodia B) branchiostegites C) lamellipodia D) setae E) cephalopodia

C) lamellipodia

The effects of natural selection may be countered by

C) mutation

Moto Kimura's theory that opposed natural selection was the A) natural theory B) nearly neutral theory C) neutral theory D) adaptive theory

C) neutral theory

David Lack's contradiction of Darwin resulted from A) changes in finches since Darwin's time B) incorrect observations by Darwin C) seasonal variations D) failure to observe carefully

C) seasonal variations

Sickle-cell trait in humans is a classic example of A) how mutations can lead only to tragic outcomes B) why outbreeding is important C) the superior fitness seen in heterozygotes D) how every organism is an integrated gene complex

C) the superior fitness seen in heterozygotes

As mammalian zygotes divide, all cells are totipotent up to the _______________ celled stage. A) 2 B) 4 C) 6 D) 8 E) 16

D) 8

As migrating cells of developing Drosophila sort themselves into groups, _______________ play the major role in holding aggregating cells together. A) collagens B) elastins C) fibronectins D) cadherins E) proteoglycans

D) cadherins

How common is genetic polymorphism in natural populations? A) essentially all loci are polymorphic B) essentially no loci are polymorphic C) depending on the species, all loci are polymorphic or none are D) depending on the species, more or less than half the loci are polymorphic

D) depending on the species, more or less than half the loci are polymorphic

Bones of vertebrates are derived from embryonic A) ectoderm B) endoderm C) epiderm D) mesoderm E) notoderm

D) mesoderm

Which of the following statements is true? A) All proteins evolve at the same rate. B) Marsupial versus placental mammals are an example of divergent evolution. C) The Galapagos finches are an example of convergent evolution. D) All of the above are true. E) None of the above is true.

E) None of the above is true.

Cell migration depends upon all of the following except: A) Ca++ binding B) cadherins C) integrins D) changing patterns of adhesion E) auxin

E) auxin

The combination of two different eight-cell stage embryos produce a A) blastula B) planula C) morula D) bicoid E) chimera

E) chimera

In the Hardy-Weinberg equation, the term 2pq represents the frequency of the A) dominant homozygotes B) recessive homozygotes C) dominant allele D) recessive allele E) heterozygotes

E) heterozygotes

In insects, like Drosophila, the action of _______________ genes determines the initial course of development. A) zygote B) larval C) paternal D) imaginal E) maternal

E) maternal

The end point of a cell's migration in embryo development is determined by the concentration of chemicals called A) regulators B) meristems C) organizers D) inducers E) morphogens

E) morphogens

True/False Knocking out a gene in a mouse always produces a profound effect on the organism.

False

The rapid divisions that occur early in development are made possible by shortening

G1 and G2 phases.

What potential problems must be considered in creating a transgenic bacterium with the human insulin gene to produce insulin?

Introns in the human gene will not be processed after transcription and the bacterial cell will be unable to posttranslationally process the insulin peptide sequence.

How is the gene for β-galactosidase used in the construction of a plasmid?

It is a marker for insertion of DNA.

Who demonstrated that industrial melanism had occurred in England?

Kettlewell

Which of the following statements is accurate for DNA replication in your cells, but not PCR?

Ligase is essential.

The possession of fine fur in 5-month human embryos indicates?

That we evolved from a hairy ancestor.

What is the common theme in cell determination by induction or cytoplasmic determinants?

The activation of transcription factors and a change in gene expression.

What is the basis of separation of different DNA fragments by gel electrophoresis?

The size of the DNA fragments.

What is Epidemiology?

The statistical analysis of human populations used to look for correlation between factors and disease incidence.

The evolution of modern horses(equus) is best described as?

a complex history of lineages that changed over time, with many going extinct.

The basic logic of organizing a genome into BAC libraries is to create

a nested set of DNA fragments that end with known bases.

Insertion of a gene for a surface protein from a medically important virus such as herpes into a harmless virus is an example of

a subunit vaccine.

Regulation by small RNAs and alternative splicing are similar in that both

act after transcription and act via RNA/protein complexes.

The lac operon is controlled by two main proteins. These proteins

act in the opposite fashion, one negative and one positive.

The lac repressor and CAP are all

allosteric proteins that bind to DNA and an effector.

Repression of the trp operon and induction of the lac operon are both mechanism that

allow the cell to control the level of enzymes to fit environmental conditions.

In each of the 3 common types of changes from a proto-oncogene into a oncogene, the change leads to what?

an increase in function.

Production of anterior-posterior and dorsal-ventral axes in the fruit fly Drosophila

are conceptually similar but mechanistically different.

Gaps in the fossil record

are expected since the probability that any organism will fossilize is extremely low.

Eukaryotic mRNAs differ from prokaryotic mRNAs in that they

are not colinear with the genes that encode them.

Homologous structures?

are structures in two or more species that originate as the same structure in a common ancestor.

In Eukaryotes, the regulation of gene expression occurs

at the level of transcription initiation, or posttranscriptionally.

The genes that encode the morphogen gradients in Drosophila were all identified in mutant screens. A mutation that removes the gradient necessary for the A/P morphogen gradient would be expected to

be lethal and lead to an abnormal embryo.

Regulatory proteins interact with DNA by

biding to the major groove of the double helix and interacting with base pairs.

Specific transcription factors in eukaryotes interact with enhancers, which may be a long distance from the promoter.These transcription factors then

can interact with the transcription apparatus via DNA looping.

As adults, humans have a vestige of a tail. It is called the

coccyx

A recombinant DNA molecule is one that is

constructed from DNA from different sources.

Plant meristems

contain stem cells.

In the cell cycle, cyclin proteins are produced in concert with the cycle. This likely involves

control of initiation of transcription of cyclin genes, and ubiquination of cyclin proteins.

In vitro mutagenesis is used to?

create organisms that carry foreign genes.

To give rise to a colony in a new site the cells of a primary tumor must?

cross the basal lamina, migrate through connective tissue and get into the blood or lymphatic vessels.

During development cells become

determined before they become differentiated.

In the colon, mutations that inactive APC initiate tumors by causing?

excessive activation of the Wnt pathway.

In Eukaryotes,binding of RNA polymerase to a promoter requires the action of

general transcription factors.

Pattern formation involves cells determining their position in the embryo. One mechanism that can accomplish this is

gradients of morphogens.

Cancer cells often have?

have highly abnormal chromosomes, reflecting genetic instability and translocations.

MADS-box, and hox-genes are

have similar roles in development in plants and animals, respectively.

The similarity of bone structure in the forelimbs of many vertebrates is an example of

homology

In the trp operon, the repressor binds to DNA

in the presence of trp

The APC protein keeps the Wnt signaling pathway?

inactive when the cell is not exposed to Wnt protein.

In prokaryotes, control of gene expression usually occurs at the

initiation of transcription

Convergent evolution depends on what?

it depends on natural selection to independently produce similar phenotypic responses in different species or populations.

Colorectal cancer often begins with?

loss of the tumor suppressor gene APC leading to growth of a polyp.

The hypothetical ancestral link between whales and hooved animals are called

mesonychids

In E.coli, induction in the lac operon and repression in the trp operon are both examples of

negative control by a repressor.

A mechanism of control in E.coli not discussed in this chapter involves pausing of ribosomes allowing a transcription terminator to form in the mRNA. In eukaryotic fission yeast, this mechanism should

not occur as transcription occurs in the nucleus and translation in the cytoplasm.

A pluripotent cell is one that can

produce multiple cell types.

Wnt signaling pathway helps to control what?

production of differentiated cells from stem cells in the intestine.

The process of nuclear reprogramming

reverses the changes that occur during differentiation.

Molecular hybridization is used to?

screen a DNA library.

The process of reproductive cloning

shows that nuclear reprogramming is possible.

Determination can occur by

the action of cytoplasmic determinants and induction by other cells.

Biston betularia is the scientific name for

the peppered moth

p53 is mutated in about what % of cancers?

~50%