PCB Chapter 19, 20 and 10

What are the meiotic events in order?

1. chromosome replication 2. chromosome condensation 3. pairing of homologs 4. formation of chiasmata 5. alignment of chromosomes at the metaphase plate 6. degradation of cohesins bound to chromosome arms 7. chromatid pairing 8. loss of cohesins near centromeres

What are the general behaviors of cancer cells?

1. reduced dependence on cell signals 2. reduced apoptosis (p53) 3. indefinte proliferation (reactivation of telomerase) 4. genetically unstable 5. invasive (lack of cadherin) 6. abnormal metabolism - increased glycolysis 7. survive in foreign tissues

You examine a worm that has two genders: males that produce sperm and hermaphrodites that produce both sperm and eggs. The diploid adult has four homologous pairs of chromosomes that undergo very little recombination. Given a choice, the hermaphrodites prefer to mate with males, but just to annoy the worm, you pluck a hermaphrodite out of the wild and fertilize its eggs with its own sperm. Assuming that all the resulting offspring are viable, what fraction do you expect to be genetically identical to the parent worm? Assume that each chromosome in the original hermaphrodite is genetically distinct from its homolog.

1/16

A diploid cell containing 32 chromosomes will make a haploid cell containing ______ chromosomes.

16

How can blood clots be inhibited?

synthetic RGD peptides can inhibit blood clots by competing with fibrinogen molecules

Which type of junction contributes the most to the polarization of epithelial cells?

tight junctions

tumors can arise from either _____________ stem cells or _________________ cells.

tissue; progenitor

Retinoblastoma was the first ______________________ gene to be discovered

tumor suppressor

In the absence of recombination, how many genetically different types of gamete can an organism with five homologous chromosome pairs produce?

32

You want to design a DNA probe used for hybridization to isolate a clone from a cDNA library. Which of the following statements about DNA probes is TRUE? a. the shorter the DNA probe used to probe the library the greater the number of colonies to which the probe might hybridize b. A DNA probe that contains sequences that span two exons is better suited to the purpose than a DNA probe that only contains sequences from one exon. c. A DNA probe that contains sequences immediately upstream of the DNA that codes for the first methionine in the open reading frame will usually not hybridize to clones in a cDNA library d. hybridization of a DNA probe to the plasmid of interest will permit the detection of the clone of interest; labeling of the DNA probe is not necessary

A

________________ produce antibodies that prevent infection and eliminate microorganisms.

B cells

Two fragments of DAN can be joined together by ______________________. Restriction enzymes that cut DNA straight across the double helix produce fragments of DNA with _______________________. A fragment of DNA is inserted into a ______________________ in order to be cloned in bacteria. A _________________ library contains a collection of DNA clones derived from mRNAs. A ______________________ library contains a collection of DNA clones derived from chromosomal DNA.

DNA ligase; blunt ends; vector; cDNA; genomic

Different tumors have different transcription patterns which is why __________________ are important for deciding the treatment options.

DNA microarrays

Why is an excess of normal deoxyribonucleoside triphospate molecules (dNTPs) needed during dideoxy sequencing?

DNA polymerase uses the dNTPs to synthesize a DNA molecule complimentary to the molecule being sequenced

DNA ligase is an enzyme used when making recombinant DNA molecules in the lab. In what normal cellular process is DNA ligase involved?

DNA replication

Antibody against growth factors that stimulate proliferation of breast cancer cells

Herceptin

A cell can crawl through a tissue because of the transmembrane ___________________________ proteins that can bind to fibronectin outside of the cell.

Integrin

With fully automated Sanger sequencing, all four chain-terminating ddNTPs can be added into a single reaction. This is different from the traditional slab gel Sanger sequencing where a different reaction had to be carried out for each ddNTP. the mixing of all four ddNTPs can be carried out because ____________________.

The fully automated Sanger sequencing reactions utilize ddNTPs each labeled with a different fluorescent tag which allows all four ddNTPs to be incorporated into a single molecule of DNA.

What are some autosomal dominant disorders?

Marfan syndrome huntington's disease high cholesterol

Antibody that binds to cell surface proteins of non-Hodgkin's lymphomas.

Rituxan

What is the difference between an oncogene and a tumor suppressor gene?

oncogenes are dominant gain of function mutations; tumor suppressor genes are recessive loss of function mutations

Antibody directed against the EGF receptor or colon cancer

Vestibix

Which of the following is the term for the variant versions of a gene?

alleles

Meiosis or Mitosis: condensation of chromosomes occurs in...

both

Meiosis or Mitosis: involvement of DNA replication...

both

What are the proteins that make up the tight junction?

claudin and occludin

PCR involves a heating step, followed by a cooling step and then DNA synthesis. What is the primary reason for why this cooling step is necessary?

cooling the reaction brings the temperature down to a level that is compatible with the short primers forming stable hydrogen bonds with the DNA to be amplified

___________________ join the intermediate filaments in one cell to those in the neighboring cell. __________________ anchor intermediate filaments in a cell to the extracellular matrix. ___________________ involve cadherin connections between neighboring cells and are anchoring sites for actin filaments. _________________ permit the passage of small molecules from one cell to its adjacent cell. ___________________ prevent the leakage of molecules between adjacent cells.

desmosomes; hemidesmosomes; adherens; gap junctions; tight junctions

_____________________ reduces gap junction communication in retinal neurons

dopamine

The plasmodesmata in plants are functionally most similar to which animal cell junction?

gap junctions.

To reproduce sexually, an organism must create haploid ____________________________ cells, or ___________________, from diploid cells via a specialized cell division called _________________. During mating, the father's haploid cells, called ________________ in animals, fuse with the mother's haploid cells, called _______________. Cell fusion produces a diploid cell called a _______________, which undergoes many rounds of cell division to create the entire body of the new individual. The cells produced from the initial fusion event include _________________ cells that form most of the tissues of the body as well as the ___________________-line cells that give rise to the next generation of progeny.

germ; gametes; meiosis; sperm; eggs; zygote; somatic; germ

A malignant tumor is more dangerous than a benign tumor because ______________________.

its cells invade other tissues.

Plants are sedentary and thus their cells have different needs from those of cells found in motile animals. For example, in plant cells, ____________________ generates the turgor pressure that drives cell growth. Plants have cell walls, but cell growth is possible in the developing tissue because the ________________________ cell walls are expandable. The __________________ cell walls are deposited once growth has stopped, and can be specially adapted to their function. Fibers made from __________________(the most abundant organic macromolecule on Earth) are found in plant cell walls, and provide tensile strength. In woody tissues, the __________________ in the cell walls makes the tissue more rigid and waterproof. The deposition of the cell wall is directed by the ______________________ cytoskeleton.

osmosis; primary; secondary; cellulose; lignin; membranous

The ____________ protein suppresses the formation of tumors and maintains genetic stability.

p53

The protein encoded by the RB gene _________ regulates the G1 to S transition.

pRB

How are blood clots formed?

platelets adhere to one another through fibrinogen bridges that bind to the platelet inetegrins

When the Wnt pathway is active cells _______________

proliferate

What are some autosomal recessive disorders?

sickle cell anemia cystic fibrosis tay-sachs disease

In a tissue, which of the following cell types divides to create a continuous supply of differentiated cells?

stem cells

What is the basal lamina composed of?

type IV collagen and laminins

Adherin junctions ______________________. a. can be used to bend epithelial sheets into tubes b. are most often found at the basal surface of cells c. are found only in adult tissues d. involve fibronectin and integrin interactions

A

Both budding yeast and the bacteria E. coli are unicellular life. Which of the following statements explains why budding yeast can undergo sexual reproduction while E. coli cannot? a. unlike E. coli budding yeast can alternate between a diploid state and a haploid state b. unlike E. coli budding yest cannot multiply by undergoing cell division c. unlike E. coli haploid budding yeast cells can undergo meiosis to produce the gametes necessary for sexual reproduction. d. E. coli DNA is unable to undergo homologous recombination, making it incapable of producing gametes.

A

During fertilization in humans, ________________________. a. a wave of Ca2+ ions is released in the fertilized egg's cytoplasm b. only one sperm binds to the unfertilized egg c. a sperm moves in a random fashion until it encounters an egg. d. several sperm pronuclei compete in the cytoplasm to fuse with the egg nucleus

A

During gel electrophoresis, DNA fragments _________________. a. travel through a matrix containing a microscopic network of pores b. migrate toward a negatively charged electrode c. can be visualized without stain or labels d. are separated on the basis of their sequence

A

Which of the following genetic changes cannot convert a proto-oncogene into an oncogene? a. a mutation that introduces a stop codon immediately after the codon for the initiator methionine b. a mutation within the coding sequence that makes the protein hypersensitive c. an amplification of the number of copies of the proto-oncogene, causing overproduction of the normal protein d. a mutation in the promoter of the proto-oncogene, causing the normal protein to be transcribed and translated at an abnormally high level

A

Which of the following statements about collagen is FALSE? a. collagen synthase organizes the mature collagen molecules into ordered collagen fibrils b. collagen is synthesized as procollagen and secreted to the outside of the cell in a secretory vesicle c. the terminal procollagen domains are cleaved by a protease in the extracellular space d. cells can break down a collagen matrix using matrix proteases

A

Which of the following statements about meiosis is TRUE? a. during meiosis, the paternal chromosomes pair with the maternal chromosomes before lining up at the metaphase plate. b. unicellular organisms that have a haploid state undergo meiosis instead of mitosis during cell division. c. meiosis produces four genetically identical cells. d. in general, meiosis is faster than mitosis.

A

Which of the following techniques is not appropriate if you want to examine the transcriptome of a specific tissue? a. in situ hybridization b. production of a cDNA library c. RNA-seq d. microarray analysis

A

A basil lamina _______________________. a. is a thin layer of connective tissue cells and matrix underlying an epithelium b. is a thin layer of extracellular matrix underlying an epithelium c. is attached to the apical surface of an epithelium d. separates epithelial cells from each other

B

A pluripotent cell ________________. a. can only be produced in the lab b. can give rise to all the tissues and cell types in the body c. can only give rise to stem cells d. is considered to be terminally differentiated

B

After the first meiotic cell division ____________________. a. two haploid gametes are produced b. cells are produced that contain the same number of chromosomes as somatic cells c. the number of chromosomes will vary depending on how the paternal and maternal chromosomes align at the metaphase plate d. DNA replication occurs

B

An individual that arises by reproductive cloning has a nuclear genome that is identical to _____________________. a. the female who donated the egg b. the adult who donated the cell for nuclear transplantation c. both the female who donated the egg and the adult who donated the cell for nuclear transplantation d. the foster mother in which the embryo is placed

B

Cells that are terminally differentiated ____________________. a. will undergo apoptosis within a few days b. can no longer undergo cell division c. are unable to move d. no longer produce RNAs

B

During recombination _______________________. a. sister chromatids undergo crossing over with each other b. chiasmata hold chromosomes together c. one crossover event occurs for each pair of human chromosomes d. the synaptonemal complex keeps the sister chromatids together until anaphase II

B

Haplotype blocks can be seen in humans because ______________. a. disease genes are found in haplotype blocks b. modern humans descended from a relatively small population of about 10,000 individuals that existed about two thousand generations ago c. some of our human ancestors interbred with Neaderthals d. new mutations cannot be introduced into existing haplotype blocks.

B

Proteoglycans in the extracellular matrix of animal tissues _______________. a. chiefly provide tensile strength b. allow cartilage to resist compression c. are linked to microtubules through the plasma membrane d. are polysaccharides composed of glucose subunits

B

Which of the following is NOT an example of a connective tissue? a. bone b. the layer of photoreceptors in the eye c. the jellylike interior of an eye d. cartilage

B

Which of the following statements about DNA libraries is TRUE? a. production of a DNA library involves the direct insertion of short DNA fragments into bacteria through transformation b. by placing the library DNA into bacteria, the bacteria can be used to amplify the desired DNA fragments from the DNA library c. individual bacteria that have taken up most of the library DNA are selected for during the construction of a DNA library d. the library DNA within the bacteria will only be replicated when it hybridizes to a DNA probe.

B

Which of the following statements about PCR is FALSE? a. PCR uses a DNA polymerase from a thermophilic bacterium b. PCR is particularly powerful because after each cycle of replication, there is a linear increase in the amount of DNA available c. For PCR every round of replication is preceded by the denaturation of the double-stranded DNA molecules d. The PCR will generate a pool of double-stranded DNA molecules most of which will have DNA from primers at the 5' ends.

B

Which of the following statements about gel-transfer hybridization (or southern blotting) is FALSE? a. this technique involves the transfer of DNA molceules from gel onto nitrocellulose paper or nylon paper b. in this technique single stranded DNA is separate by electrophoresis c. a labeled DNA probe binds to the DNA by hybridization d. the DNA that is separated on a gel is not labeled

B

Which of the following statements about restriction nucleases is FALSE? a. A reproducible set of DNA fragments will be produced every time a restriction nuclease digests a known piece of DNA b. restriction nucleases recognize specific sequences on single-stranded DNA c. some bacteria use restriction nucleases as protection from foreign DNA d. some restriction nucleases cut in a staggered fashion, leaving short, single-stranded regions of DNA at the ends of the cut molecule

B

Which of the following statements is FALSE? a. asexual reproduction typically gives rise to offspring that are genetically identical. b. mutations in somatic cells are passed on to individuals of the next generation. c. sexual reproduction allows for a wide variety of gene combinations d. gametes are specialized sex cells

B

During DNA renaturation, two DNA strands will ____________ a. break the covalent bonds that hold the nucleotides together while maintaining the hydrogen bonds that hold the two strands together b. break the hydrogen bonds that hold the two strands together with no effect on the covalent bonds that hold the nucleotides together c. re-form a double helix if the two strands have complimentary sequences d. re-form a double helix if the two strands are identical in sequence

C

Somatic cells _________________. a. are not necessary for sexual reproduction in all eukaryotic organisms b. are used to produce germ-line cells when organisms reach sexual maturity c. leave no progeny d. do not contain sex chromosomes

C

The single nucleotide polymorphisms found in the human population ____________________. a. are important for genetic mapping because they represent mutations in genes important for human disease b. are rarely found among blood relatives c. can be linked into haplotype blocks d. arose mainly during the past 10,000 years

C

There are organisms that go through meiosis but do not undergo recombination when forming haploid gametes. Which of the following statements correctly describes the gametes produced by such an organism? (Assume that these organisms are diploid, that each of the two homologous chromosomes are genetically distinct as typically found in the wild, and that these organisms have more than one chromosome). a. all gametes formed during a single meiosis will be identical. b. due to the random assortment of homologs, eahc of the gametes formed during a single meiosis will be different. c. this organism could potentially produce 2^n genetically distinct gametes, where n is its haploid number of chromosomes. d. the fusion of an y two gametes produced by such an organism that does not undergo recombination during meiosis will create a cell that is genetically identical to that individual.

C

Which of the following does not describe a situation of asexual reproduction? a. A bacterium multiplying by simple cell division. b. Using a part of a plant to creat a new independent plant. c. Using in vitro fertilization to combine a sperm and an egg to creat an embryo. d. The parthenogenetic development of eggs produced by some species of lizards.

C

Which of the following molecules is NOT found in plants? a. cellulose b. lignin c. collagen d. pectin

C

Which of the following statements about RNA interference (RNAi) is FALSE? a. RNAi is a natural mechanism used to regulate genes b. during the process of RNAi hybridization of a small RNA molecule with the mRNA degrades the mRNA c. because RNAi depends on the introduction of a double-stranded RNA into a cell or an organism it is not a process that can cause heritable changes in gene expression d. in c. elegans RNAi can be introduced into the animals by feeding them with bacteria that produce the inhibitory RNA molecules

C

Which of the following statements about cancer is FALSE? a. viruses cause some cancers b. tobacco use is responsible for more than 20% of all cancer deaths c. a mutation in even a single cancer-critical gene is sufficient to convert a normal cell into a cancer cell. d. chemical carcinogens cause cancer by changing the nucleotide sequence of DNA.

C

Which of the following statements about gap junctions is FALSE? a. gap junctions are made of connexons b. molecules up to 1000 daltons in molecular mass can move across gap junctions c. because gap junctions do not allow ions to pass through, they are not used for electrically coupling cells d. gap junctions can close in response to extracellular signals

C

Which of the following statements about genomic DNA libraries is FALSE? a. the larger the size of the fragments used to make the library the fewer colonies you will have to examine to find a clone that hybridizes to your probe b. the larger the size of the fragments used to make the library the more difficult it will be to find your gene of interest once you have identified a clone that hybridizes to your probe c. the larger the genome of the organism from which a library is derived, the larger the fragments inserted into the vector will tend to be d. the smaller the gene you are seeking the more likely it is the gene will be found on a single clone.

C

Which of the following statements is FALSE? a. proteoglycans can act as filters to regulate which molecules pass through the extracellular matrix b. the negative charge associated with proteoglycans attracts cations, which cause water to be sucked into the extracellular matrix c. proteoglycans are a major component of compact connective tissues but are relatively unimportant in watery tissues such as jellylike substance in the interior of the eye d. glycosaminoglycans are components of proteoglycans

C

Which of the following would NOT lead to aneuploidy during meiosis? a. sister chromatids segregating inappropriately b. non-sister chromatids segregating inappropriately c. a reciprocal rearrangement of parts between nonhomologous chromosomes (for example the left arm of chromosome 2 exchanging places with the right arm of chromosome 3) d. an extra set of chromosomes produced during S phase (for example if paternal chromosomes 3 were replicated twice).

C

You create a recombinant DNA molecule that fuses the coding sequence of green fluorescent protein to the regulatory DNA sequences that control the expression of your favorite genes. Which of the following pieces of information can you NOT gain by examining the expression of this reporter gene? a. the tissue where the protein encoded by this gene is expressed b. the cell in which the protein encoded by this gene is expressed c. the specific location within the cell of the protein encoded by this gene d. when, during an organism's development this gene is expressed

C

A single nondisjunction event during meiosis __________________. a. will block recombination b. will occur only during meiosis II c. cannot occur with sex chromosomes d. will involve the production of two normal gametes if it occurs during meiosis II.

D

Both multicellular plants and animals have _________________. a. cells capable of locomotion b. cells with cell walls c. a cytoskeleton composed of actin filaments, microtubules, and intermediate filaments d. tissues composed of multiple different cell types

D

DNA can be introduced into bacteria by a mechanism called ___________________. a. transcription b. ligation c. replication d. transformation

D

Hemidesmosomes are important for ___________________. a. tubulation of epithelial sheets b. linkages to glycosaminoglycans c. forming the basal lamina d. attaching epithelial cells to the extracellular matrix

D

Mouse embryonic stem (ES) cells ______________________. a. can only be produced through therapeutic cloning b. can give rise to all tissues and cell types in the body except germ cells c. can be implanted in foster mothers to produce cloned cows and other animals d. come from the inner cell mass of early embryos

D

Organisms that reproduce sexually _______________________. a. must be haploid, unlike organisms that reproduce asexually. b. can reproduce only with a partner that carries the same alleles. c. create zygotes that are genetically identical to each other. d. undergo a sexual reproductive cycle that involves an alternation of haploid cells with the generation of diploid cells

D

Which of the following is the least likely reason for Lupus to occur? a. a defect in programmed cell death b. inappropriate cytokine production by T cells c. uncontrolled antibodies directed to self DNA d. targeted destruction of pancreatic beta cells

D

Which of the following reasons was essential for Mendel to disprove the theory of blended inheritance? a. the traits that Mendel examined all involved genes that did not display linkage b. the traits that mendel examined all involved the reproductive structures of the pea plant c. mendel pioneered techniques permitting the fusion of male and female gametes from the same plant to produce a zygote d. the traits that mendel examined involved an allele that was dominant and an allele that was recessive.

D

Which of the following statements about Mendel's experiments is FALSE? a. the pea plants could undergo both cross-fertilization and self-fertilization b. the true-breeding strains were homozygous for the traits that Mendel examined c. the egg can carry either the allele from the maternal or the paternal chromosome d. all traits that Mendal studied were recessive.

D

Which of the following statements about cellulose is FALSE? a. cellulose synthase enzyme complexes are integral membrane proteins b. an array of microtubules guides the cellulose synthase complex as it moves in the membrane c. the sugar monomers necessary for the synthesis of a cellulose polymer are transported across the plasma membrane d. microtubules are directly attached to the outside surface of the plasma membrane to form tracks that help orient the cellulose polymers

D

Which of the following statements most correctly describes meiosis? a. meiosis involves two rounds of DNA replication followed by a single cell division b. meiosis involves a single round of DNA replication followed by four successive cell divisions c. meiosis involves four rounds of DNA replication followed by two successive cell divisions d. meiosis involves a single round of DNA replication followed by two successive cell divisions.

D

You have been hired to create a cat that will not cause allergic reactions in cat lovers. Your coworkers have cloned the gene encoding a protein found in cat saliva, expressed the protein in bacteria, and shown that it causes allergic reactions in people. But you soon realize that even if you succeed in making a knockout cat lacking this gene, anyone who buys one will easily be able to make more hypoallergenic cats just by breeding them. Which of the following will ensure that people will always have to buy their hypoallergenic cats from you? a. inject the modifed embryonic stem (ES) cells into embryos that have a genetic defect to prevent the mature adult from reproducing b. implant the injected embryos into a female cat that is sterile as a result of a genetic defect c. sell only the offspring from the first litter of the female cat implanted with the inject embryos d. surgically remove the sexual organs of all knockouts before you sell them.

D

loss of function mutations ____________________. a. cause the production of proteins that are active in inappropriate circumstances b. will usually show a phenotype when heterozygous c. are only present in a population at barely detectable levels. d. are usually recessive

D

Innate immune system molecules including _________________ and ________________________ opsonize apoptotic blebs and facilitate phagocytosis.

antibodies and macrophages

__________________ kill infected, cancerous cells.

cytotoxic T cells (MHCI)

During gel __________________, DNA fragments can be loaded into one end of an agrose slab to separate the fragments on the basis of charge. As ____________________ is applied across the agrose slab, the DNA molecules, which have a ________________ charge, will migrate toward the ____________________ electrode. Because ________________ DNA fragments will migrate more quickly they will be found furthest away from the area of the gel where the DNA fragments were loaded. One method to visualize the DNA on the agrose slab involves staining the DNA with a dye that will _____________________ under ultraviolet light.

electrophoresis; voltage; negative; positive; smaller; fluoresce

________________ activate phagocytic cells to kill microbes.

helper T cells (MHCII)

What are some X linked disorders?

hemophilia color blindedness

An individual that possesses two different alleles is said to be ______ for that trait.

heterozygous

What are hematopoietic cytokines generate by?

macrophages, stromal cells, and activated T cells

Meiosis or Mitosis: formation of bivalents occur in....

meiosis

genetically identical products occur in...

mitosis

Mitosis or Meiosis: segregation of all paternal chromosomes to one cell...

neither

Gregor Mendel studied pea plants and developed some very important ideas about how genes are inherited. These studies used plant strains that were true breeding and always produced progeny that had the same ________________ as the parent. These strains were true breeding because they were _______________ for the gene important for a specific trait. In other words, for these true-breeding strains, both chromosomes in the diploid pea plant carried the same ______________________ of the gene. Mendel started out examining the inheritance of a single trait at a time, and then moved on to examining two traits at once in a ___________________ cross. His studies examining the inheritance of two traits in one cross allowed him to discover what is now known as Mendel's law of ________________ assortment. Geneticists can study the inheritance of specific traits in humans by analyzing a ___________________, which shows the phenotypes of different family members over several generations for a particular trait.

phenotype; homozygous; allele; dihybrid; independent; pedigree

A nuclease hydrolyzes the ___________________ bonds in the nucleic acid. Nucleases that cut DNA only at specific short sequences are known as _________________________. DNA composed of sequences from different sources is known as ______________________. __________________ can be used to separate DNA fragments of different sizes. Millions of copies of a NDA sequence can be made entirely in vitro by the ______________________ technique.

phosphodiester; retriction nucleases; recombination DNA; electrophoresis; PCR

When terminally differentiated cell in an adult body dies, it can typically be replaced in the body by a stock of ___________________.

proliferating precursor cells