BIOL 1201 Chapter : BIOL 1201 3 6

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15 Mar 2019

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Cells need to possess the genetic material characteristic of the organism: genetic material is dna, the daughter cells need the complete genetic complement. Prokaryotes: circular strands of dna, replicate the dna and pass it on to the daughter cells, divide by binary fission. Eukaryotes: a problem, genetic material is found in linear chromosomes, linear strands of dna complexed with proteins, multiple chromosomes (e. g. humans 46) How to ensure that each daughter cell gets the complete set of chromosomes: how do you get identical daughter cells, need a mechanism to allow each daughter cell to have a copt of each chromosome. Cell division: mitosis: reproduction, growth, repair, produce daughter cells that have identical genetic complements, occurs in somatic cells. Somatic cells: all body cells except cells which give rise to gametes. Chromosomes: a complex of a linear strand of dna and protein, each eukaryotic species has a characteristic number, found in the nucleus.

Related Questions

What is the difference between chromatin and chromosomes?

Question options:

	chromatin is one of two identical strands of DNA.
	chromosomes are chromatin that has been tightly packed and coiled.
	chromosomes are composed of nucleosomes and chromatin is composed of sister chromatids.
	chromosomes are important in mitosis and chromatin is essential to meiosis.

Bacterial cells only reproduce asexually and cannot exchange genetic material.

Question options:

	True, because they undergo binary fission.
	False, because they transfer genetic material with other bacterial cells.
	True, because they have a cell wall that prevents sharing of genetic material.

After a visit to a specialist, Dan was diagnosed with liver cancer. Six months later additional tumors were found in his stomach and small intestine. This is an example of

Question options:

	malignant tumors.
	benign tumors.
	Both malignant tumors and metastasis are correct.

Which of the following does NOT occur during mitosis?

Question options:

	DNA is replicated.
	Replicated chromosomes divide.
	Cells line up along the equator of the cell.

Which of the following is INCORRECTLY matched?

Question options:

	prophase -- mitotic spindle forms
	metaphase -- chromosomes line up along the equator
	telophase -- cytoplasm divides

Why is hair loss a common side effect of cancer treatments?

Question options:

Hair cells are at the surface of the body so die easily.

Hair cells divide rapidly and so are targeted by the cancer drugs.

Cancer drugs often target and kill random cells within the body.

From "Investigating Life: Cutting Off a Tumor's Supply Lines in the War on Cancer," how are endostatins used to treat cancerous cells?

Question options:

	They prevent angiogenesis by cancerous cells.
	They promote growth of new blood vessels to feed cells.
	They bind to receptors on cancerous cells and prevent cells from reproducing.

1)What experiment was performed that allowed for scientists to finally agree that DNA is the genetic material within living organisms?

a.Understand the materials and scientific techniques used to come to this result.

2)What group of experiments led to the discovery of the mechanism used in DNA replication?

a.Understand the materials and scientific techniques used to come to this result.

i.What is a cesium chloride gradient?

ii.Where do 14N and 15N respectively fall along this gradient?

b.The results revealed that DNA replicates using which of the three proposed models?

i. Describe the mechanism of each model.

3)What is the role of the following proteins in DNA replication?

a.Helicase

b.Single strand binding proteins

c.Topoisomerase

d.DNA polymerase III

e.DNA polymerase I

f.Primase

g.Ligase

4)What extra steps are taken to be sure the lagging strand does not shorten each time DNA is replicated?

a.What is the role of telomerase in these âstepsâ?

5)In DNA repair, which enzyme has âproof-readingâ capabilities?

1)Which type of cells within our bodies use mitosis to reproduce?

2)Does mitosis create a cell that is different or the same as the parent cell undergoing division?

3)Describe the DNA found in sister chromatids.

4)Describe the DNA found in homologous chromosomes.

5)What occurs during the following stages of the cell cycle?

a.G₁ Phase

b.S Phase

c.G₂ Phase

d.M Phase

What are the phases of mitosis? What events occur in each phase?

1)Does mitosis separate homologous chromosomes, sister chromatids, or both?

2)What is cytokinesis?

a.Which fibers of the cytoskeleton contract to pinch parent and daughter cells apart from one another in animals?

b.How do microtubules move chromosomes to the two poles of a dividing cell?

3)How are centrioles involved in this process?

a.How do plants form two complete cells during cytokinesis?

4)How do bacterial cells reproduce?

5)The cell cycle is controlled at âcheckpointsâ. What occurs at each of the following checkpoints?

a.G₁ Checkpoint

b.G₂ Checkpoint

c.M Checkpoint

6)How do cyclin and cdk act to control the G2 checkpoint?

7)If presented with the schematic of the M checkpoint, you should be able to explain perturbations to the system as well as if the cell will divide or stall at metaphase.

8)Cancerous cells form when the cell cycle checkpoints do not function correctly and continues to divide even though it is damaged in some way. How does the protein p53 function to keep these cells from dividing?

9)Normal cells follow certain rules of growth that cancerous cells do not follow. What are these rules (provide a short definition for each as well)?

10)What is the difference between a benign tumor and a malignant tumor?

indigohedgehog242

In addition to identifying the genetic material, the experiments of Avery, MacLeod, and McCarty with different strains of Streptococcus pneumoniae demonstrated that

	DNA is a double helix.
	DNA may be taken up by bacterial cells and be active.
	DNA is present in bacteriophage T2.
	eukaryotic cells may be genetically transformed.
	DNA binds to the cell wall of the bacterium.

In order to show that DNA in cell extracts is responsible for genetic transformation in Streptococcus pneumoniae, important corroborating evidence should indicate that _______ also destroy transforming activity.

	temperatures high enough to kill cells
	enzymes that hydrolyze proteins
	enzymes that hydrolyze DNA
	enzymes that hydrolyze polysaccharides
	enzymes that hydrolyze RNA

Based on what you have learned about the experiments conducted by Griffith and Avery and colleagues with bacteria, which of the following would result in transformation of living R cells?

	Pure RNA from S cells
	Cell-membrane extracts from S cells
	A mixture of pure RNA and protein from S cells
	Cell-free extracts from S cells
	Pure protein from S cells

A-T base pairs in a DNA double helix

	form three hydrogen bonds with each other.
	are more heat-stable than G-C base pairs.
	are of a substantially different length than G-C base pairs.
	are not accessible to DNA binding proteins.
	are chemically distinct from G-C base pairs.

If 23 percent of the bases in a sample of double-stranded DNA are adenine, what percentage of the bases are uracil?

	27
	50
	0
	73
	23

The uniform diameter of the DNA structure provides evidence for

	antiparallel DNA strands.
	a right-handed helix.
	a double-stranded helix.
	3â² end phosphorylation.
	purineâpyrimidine pairing.

If a sequence of one strand of DNA is 5â²-TGACTATC-3â², what is the complementary strand?

	5â²-ACTGATAG-3â²
	3â²-TGACTATC-5â²
	3â²-ACTGATAG-5â²
	3â²-ACTGATAG-3â²
	5â²-TGACTATC-3â²

What structural aspect of the DNA facilitates dissociation of the two DNA strands for replication?

	3â² end phosphorylation
	Purineâpyrimidine pairing
	Antiparallel DNA strands
	Covalent bonds between sugars and phosphate groups
	Hydrogen bonding between paired bases

If the MeselsonâStahl density gradient experiment had resulted in two bands of DNA molecules after only one round of replication, one containing only ¹⁵N and the second only ¹⁴N, this result would have indicated that replication was

	unidirectional.
	dispersive.
	conservative.
	bidirectional.
	semiconservative.

10.

The nucleoside analogue acyclovir, which is used to treat herpes simplex virus (HSV) infections, lacks a 3â² hydroxyl group (âOH). Predict what will happen if the host cell DNA polymerase incorporates a molecule of acyclovir into an elongating strand of HSV DNA.

	The replication complex will no longer bind to origins of replication.
	The DNA polymerase will only incorporate acyclovir molecules.
	Acyclovir will bind single-strand binding proteins.
	DNA polymerase will not be able to link a successive nucleotide.
	Acyclovir will block the activity of the DNA helicase.

11.

Which of the following does not demonstrate the stability of the DNA double helix?

	Single-strand binding proteins are required to keep the strands apart.
	Paired bases form hydrogen bonds.
	High temperatures are required to denature it.
	DNA synthesis requires energy.
	DNA helicases require ATP.

12.

What effect would a primase inhibitor have on DNA replication?

	DNA polymerase would not be able to add bases to the DNA.
	Primase would be blocked from joining the DNA replication complex.
	Primase would not be able to provide primers for DNA polymerases.
	DNA polymerase would not be able to use DNA as a template.
	There would be no effect on DNA replication.

13.

To replicate their DNA in a timely manner, most eukaryotic chromosomes

	normally have uncoiled DNA.
	have multiple origins of replication.
	contain linear molecules of single-stranded DNA.
	have two replication forks that move in the same direction.
	are composed entirely of DNA.

14.

Which statement about DNA replication is false?

	Okazaki fragments are synthesized as parts of the leading strand.
	Error rates for DNA replication are reduced by proofreading of the DNA polymerase.
	The sliding clamp increases the rate of DNA synthesis.
	Replication forks represent areas of active DNA synthesis on the chromosomes.
	Ligases and polymerases function in the vicinity of replication forks.

15.

In many eukaryotes, there are repetitive sequences called telomeres at the ends of chromosomes. After successive rounds of DNA replication, the _______ strand becomes shorter. In some cells, an enzyme called _______ repairs the shortened strand.

	leading; telomerase
	lagging; telomerase
	lagging; DNA polymerase I
	leading; DNA polymerase I
	leading; replicase

16.

A researcher studies normal human fibroblast cells. They can be maintained in culture but die off after about 30 cell generations. Unexpectedly, a colony of cells continues to survive and divide past 30 generations. Which scenario is most likely true for these cells?

	DNA polymerase is constantly active.
	Primase is able to extend the telomeres.
	The mismatch repair system is extra efficient.
	The telomerase gene is being expressed.
	The cells do not need the ends of their chromosomes.

17.

If DNA polymerase III introduces an incorrect nucleotide, what is the first corrective action made by the DNA repair system?

	The replication complex excises the incorrect nucleotide.
	The excision repair proteins remove the incorrect nucleotide.
	The mismatch repair system scans for base-pairing mismatches.
	There is no correction, because nucleotide errors by DNA polymerases are not repaired.
	DNA ligase connects the correct nucleotide.

18.

Choose the correct order of the following four events in the excision repair of DNA:
(1) Base-paired DNA is made complementary to the template.
(2) Damaged bases are recognized.
(3) DNA ligase seals the new strand to existing DNA.
(4) Part of a single strand is excised.

	1, 2, 3, 4
	2, 1, 3, 4
	3, 4, 2, 1
	2, 4, 1, 3
	4, 2, 3, 1

19.

Six complete cycles of PCR should result in a _______-fold increase in the amount of DNA.

	64
	32
	12
	128
	6

20.

When double-stranded DNA is heated to temperatures above 90Â°C, it denatures. Denaturation is a process that

	breaks covalent bonds.
	hydrolyzes DNA.
	separates double-stranded DNA into two single strands.
	causes new hydrogen bonds to form.
	irreversibly destroys the double helical structure.

BIOL 1201 Chapter : BIOL 1201 3 6

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