Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology 219 WVU > Exam 3 (DNA, Epigenetics, Junctions) > Flashcards

Exam 3 (DNA, Epigenetics, Junctions) Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What does the DNA in a resulting daughter cell look like?

A

The double helix in each daughter cell concises of one parental strand and one newly synthesized strand.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the directionality of synthesis in DNA replication?

A

The 5’-3’ direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In the formation of single-stranded DNA templates what bonds need to be broken?

A

Hydrogen Bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In a DNA double helix, which strand serves as the template during replication?

A

Both strands serve as templates during replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain DNA replication initiation.

A

Short piece of RNA, called a primer, provides a starting point for DNA polymerase. This short RNA sequence is synthesized by am enzyme called primase. RNA primers are about 10 nucleotides long and base-pair to the template strand, which provides a base-paired 3’ end as a starting for DNA polymerase enzyme.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What enzyme replicates the ends of linear chromosomes?

A

Telomerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Explain telomerase function.

A

Telomerase extradons telomere repeat sequences at he end of chromosomes by extending the template of the lagging strand. The incomplete lagging strand will be extended by polymerase, using the extended template.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What process occurs only in S phase of the cell cycle?

A

DNA replication. Prepares for cell division.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the contractile ring made of ?

A

Mainly actin and myosin filaments arranged in a rang around the equator of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do mitotic spindles and contractile ring do?

A

Carry out nuclear division (mitosis), and in animal cells and many unicellular eukaryotes, the contractile ring carries out cytoplasmic division (cytokinesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are mitotic spindles and the contractile ring able to disassemble rapidly?

A

Dynamic instability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are mitotic spindles made of?

A

Microtubules, microtubules-associated motor proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Mitotic spindle fucntion?

A

Responsible for separating the duplicated chromosomes and allocating one copy of each chromosome to each daughter cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain Metphase

A

Replicated chromosomes align along the cell equator as a result of the spindle microtubules pulling on the bound sister chromatids. Metaphase = mirrors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain anaphase

A

Degradation of the cohesion’s holding the sister chromosomes together, allowing the individual chromatids to be pulled away. Anaphase = Annihilation/Away

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why does the nuclear envelope break down at the start of prometaphase?

A

Nuclear laminés and nuclear pore components are phosphorylated by M-Cdk, which triggers the breakdown of the nuclear envelope. Necessary step, spindle microtubules cannot gain access to the duplicated chromosomes until the nuclear envelope is gone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Explain contractile ring

A

Made of actin and myosin located in the cell cortex. As actin slides past myosin, it causes the plasma membrane to pinch, which eventually results in the formation of two separate cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain process of meiosis.

A

Meiosis begins with a single round of DNA replication in a diploid (2n) cell, followed by two rounds of cell division: meiosis I and meiosis II. This sequence produces a haploid (n) set of chromosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain gamete

A

Carries a single allele for each gene. Due to diploid genome is reduced to a haploid genome within each viable gamete.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How are maternal and paternal chromosomes shuffled and distributed randomly during meiosis I?

A

Independent assortment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Explain Depurination.

A

Spontaneous occurring event involving the loss of adenine (A) or guanine (G) bases from DNA. This removes a purine base while keeping the phosphodiester bond intact, leaving a gap in the DNA’s complimentary base pairing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does UV radiation in sunlight typically damage DNA?

A

It causes two adjacent pyramiding bases to become covalently linked. Covalently linked thymine bases are called thymine dimers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Define Mutation.

A

Permanent change in DNA sequence, arising from ineffective DNA repair and/or errors during DNA replication, which could alter an organisms ability to serve and reproduce.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What enzyme removes damaged DNA from the rest of the DNA molecule?

A

Nuclease: Breaks the phosphodiester bonds that hold the damaged or incorrect nucleotide in the DNA strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What enzyme fills in the gap after damaged DNA has been removed?

A

Repair Polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What enzyme seals the newly added (repaired) DNA to the rest of the DNA molecule?

A

Ligase: Catalyzes the formation of phosphodiester bonds between DNA fragments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What occurs when a cell repairs a double-strand DNA break by the process of non homologous end joining?

A

DNA sequence at the of repair is altered by a short deletion. Nuclease enzymes “clean” the broken DNA ends before joining them back together with DNA ligase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What occurs when a cell repairs a double-strand DNA break by the process of homologous recombination end joining?

A

Uses an undamaged DNA molecule as a template to correct the damaged DNA, using nucleotides to replicate the template strand.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Double strand breaks can be repaired flawlessly by?

A

Homologous recombination

30
Q

Does homologous recombination help generate diversity? Yes or No

A

Yes

31
Q

Homologous recombination is also responsible for generating genetic diversity during what process?

A

Meiosis

32
Q

How de so Polymerase help maintain the accuraury of DNA replication?

A

DNA polymerase can cut out improperly base-paired nucleotides and add the correct one during synthesis.

33
Q

In bacteria, how does the cell recognize which strand is the newly synthesized strand and this contains the mismatch?

A

Adenine bases are methylated. This occurs slowly, so newly synthesized strands remain unmethylated for a time after replication and gives mismatch repair enzymes time to recognize the damaged stand.

34
Q

How can a cell change the expression of its genes?

A

Cells response to external signals, allow adaption to environmental conditions.

35
Q

What are general transcription factors?

A

Accessory proteins that help position RNA polymerase at the promoter in all cell types. Generally, a single transcription regulator can coordinate the expression of many different genes.

36
Q

What do Eukaryotic activator proteins do?

A

Help initiate gene transcription through mechanisms.
1) Can recruit enzymes that will modify histones, thereby enablign them to bind other proteins necessary for transcription initiation.
2) Also, chromatic-0remodeling complexes can reconfigure chromatic to make it more accessible machinery. Do this by amino the TATA box more accessible, for example.

37
Q

In eukaryotes, where do transcription regulators bind?

A

Upstream, downstream, or within genes they control

38
Q

What must activator proteins do before they can interact with DNA?

A

Function by binding to the promoter region of genes and helping RNA polymerase to initatiate transcription. Bind to a metabolite or other small molecule

39
Q

Transcription initatiation site of a eukaryotic gene is found at which location?

A

Where RNA synthesis begins

40
Q

To reinforce cell identity, vertebrate cells can methylate which nucleotide?

A

Cytosine that falls next to guanine in the sequence CG 5’-CG-3’. These enables differentiated cells to maintain their differentiation because methylated genes will not be transcribed.

41
Q

What is epigenetic inheritance?

A

Involves transmission of gene expression patterns that do not involve a change in nucleotide sequence, for example, DNA methylation. These types of modification allow cell memory to be established from even a short-lived environmental signal.

42
Q

What does methylation pattern have on transcription?

A

Methylation is an example of epigenetic inheritance, where gene expression patterns are passed on from parent cell to daughter cell without a change in nucleotide sequence. Methylation functions to prevent gene transcription and can be maintained even through rounds of RNA replication and cell division.

43
Q

Eukaryotic repressors proteins can decrease transcription using which of the following mechanisms?

A

Preventing the assembly of the transcription initiation complex by inhibiting assembly with repressors proteins, or recruit histone-modifying completes like deacetylases, which remove the activating actual groups from nearby histones.

44
Q

MicroRNAs regulate the activity of protein-coding genes by doing which of the following?

A

Inhibiting the translation of mRNAs, Promoting the degradation of mRNAs, through the action of RISC and other nucleases.

45
Q

What do mRNA code for?

A

Protein synthesis, they are coding RNAs, in fact the only RNAs that do encode proteins.

46
Q

What are noncoding RNAs?

A

Do not encode proteins and are therefore not translated by the ribosome.

47
Q

What RNAs are noncoding?

A

miRNA, tRNA, and rRNA are all noncoding; they have no start translation codon and are therefore never translated into proteins.

48
Q

What is the fate of an mRNA that is targeted by a miRNA?

A

mRNA will be destroyed by nucleases, done through complementary base pairing and preventing their translation, miRNA is not degraded after process.

49
Q

Control of gene products levels or activity after transcription has taken place is called?

A

Post-transcriptional control

50
Q

Explain phosphorylation in a cell.

A

Covalent modification that affects a proteins activity or location occurring in the cytoplasm. Example, when extracellular signals stimulate a class of cell-surface, transmembrane proteins called receptor tyrosine kinases, they cause the receptor proteins to phosphorylation themselves on certain tyrosines. The phosphorylated tyrosines then serve as docking sites for the binding and activation of a set of intracellulaire signal proteins, which transmit the message to the cell interior and changes the behavior of the cell.

51
Q

What enzyme removes a phosphate group from a protein?

A

Removal “Dephosphorylation”: Catalyzed by protein phosphatase, GTPases and ATPases are a class of enzymes that catalyze the decomposition of GTP into GDP and a free phosphate ion and ATP into ADP and a free phosphate ion.

52
Q

What adds a phosphate group to another protein?

A

Kinase: enzyme-catalyzed transfer of the terminal phosphate group of ATP to the hydroxyl group ona. Shrine, Threonine, or tyrosine side chain of the protein. This reaction is catalyzed by a protein kinase.

53
Q

Where do chemical modifications like phosphorylation and acetylation of proteins occur on?

A

Side chains

54
Q

A fibroblast can attach indirectly to collagen via which type of extracellular matrix protein?

A

Fibronectin: Provides a linkage between the cell and collagen; part of the fibronectin molecule Nissan to collagen, while another part for as an attachment site for integrans. Integrans are proteins in the plasma membrane that help animal cells bind to components of the extraceullur matrix, including fibronectin.

55
Q

Which type of protein in a fibroblasts plasma membrane attaches to the extracellualr matrix on the outside of the cell and (through adapter molecules) to actin inside the cell?

A

Integrin

56
Q

Which feature of the glycosaminoglycans 9GAGs, also know as the hydrated matrix) allows the extracellualr matrix in cartilage to resist compression?

A

Negative charges on GAGs attract sodium ions, which draw water into the extracellular matrix to form a water-filled gel.

57
Q

Explain tight junctions.

A

Serve to seal neighboring cells together so that water-soluble molecules cannot easily leak between them. If a tracer molecule is added to one side of an epithelial sheet, it will usually not pass beyond the tight junction.

58
Q

Explain Desmosomes and Adherins.

A

Junctions that mechanically link an epithelial cell to it neighbor in an epithelium.

59
Q

Explain gap junctions.

A

Allow water-soluble molecules to move directly from the cytosol of one cell to the cytosol of an attached cell.

60
Q

Which of the following junction is not involved in providing mechanical strength to an epitheal sheet by connecting the cytoskeletons of adjacent cells? 1) Adheren Junction
2) Hemidesmosomes
3) Desomosomes
4) Gap Junction

A

Gap junctions

61
Q

What do Cadherin proteins bind to and do?

A

Links epithelial cells together by binding to an identical cadherin molecule in the plasma membrane of its neighbor. Interaction of like-with like ic allied homophilic binding.

62
Q

What do Integrins bind to?

A

In the plasma membrane of epithelial cells anchor the cells out he base lamina by bind to laminins.

63
Q

What is the order of smallest unit of organization tot he largest?

A

Cells < tissues < organs

64
Q

Explain the attachment of a cell to a collagen molecule in the extracellualr matrix

A

Secretion of another extracellular matrix protein called fibronectin, binds to collagen. Integrins that are transmembrane proteins bind to fibronectin molecules, this linking to the collagen fibers in the extracellular matrix.

65
Q

Gel electrophoresis separate DNA fragments from each other by virtue of which feature?

A

Length

66
Q

What DNA fragments will migrate the fastest in a gel?

A

Smallest fragments

67
Q

What is not a typical plasmid method used in a research laboratory?

A

Insertion fo the gene of interest into the bacterial chromosome

68
Q

In a polymerase chain rxn, what is used to separate the two strands of double-stranded DNA molecule?

A

High heat

69
Q

What can Sanger sequencing be used to do?

A

Determine the nucleotide sequence of any purified DNA fragment

70
Q

What does PCR use to withstand high heat?

A

Polymerase isolated form a thermophilic bacterium

Biology 219 WVU (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions