Heredity B/Designer Genes C

[Phenakism]

1. What are nucleosomes?
2. Why does X inactivation occur?
3. What are some common applications of PCR?
4. Briefly explain mosaicism

1.

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 Nucleosomes are the functional packing units in chromatin, with DNA being wrapped around an octamer 1.65 times along with the H1 linker histone. 

2.

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 It's toxic to the cell to have 2 X chromosomes, as it will produce twice the amount of proteins needed. Therefore, cells randomly deactivate one of the chromosomes. 

3.

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PCR can be used to diagnose genetic diseases which deal with the mutations of the reading frame, construct forensic genetic fingerprinting through comparing the DNA samples of multiple suspects, and can find whether cells are under the influence of harmful viruses from RNA reverse-transcription.

4.

Click to Show Answer

 Mosaicism is when some cells have a different genetic code then the rest of the cells, resulting in some cells expressing differently then others. This can result from random X-deactivation or a genetic mutation after fertilization in only some of the cells. 

[Phenakism]

1. What are nucleosomes?
2. Why does X inactivation occur?
3. What are some common applications of PCR?
4. Briefly explain mosaicism

1.

Click to Show Answer

 Nucleosomes are the functional packing units in chromatin, with DNA being wrapped around an octamer 1.65 times along with the H1 linker histone. 

2.

Click to Show Answer

 It's toxic to the cell to have 2 X chromosomes, as it will produce twice the amount of proteins needed. Therefore, cells randomly deactivate one of the chromosomes. 

3.

Click to Show Answer

PCR can be used to diagnose genetic diseases which deal with the mutations of the reading frame, construct forensic genetic fingerprinting through comparing the DNA samples of multiple suspects, and can find whether cells are under the influence of harmful viruses from RNA reverse-transcription.

4.

Click to Show Answer

 Mosaicism is when some cells have a different genetic code then the rest of the cells, resulting in some cells expressing differently then others. This can result from random X-deactivation or a genetic mutation after fertilization in only some of the cells. 

All correct, your turn!

[Phenakism]

1. What is miRNA and how does it work?
2. What does the TATA box have to do with RNA transcription and why is it called a "box"?
3. How does RNA polymerase know when to stop transcribing along the template strand?

[reninkidney]

1. What is miRNA and how does it work?
2. What does the TATA box have to do with RNA transcription and why is it called a "box"?
3. How does RNA polymerase know when to stop transcribing along the template strand?

1. A microRNA regulates genes by binding to some mRNAs & shutting them down.
2. The TATA box is an region of DNA upstream the gene. It consists of T's & A's. It signals the start of transcription.
3. When the polymerase reaches the termination site, the mRNA forms a 'hairpin' structure which releases the polymerase.

[Phenakism]

1. What is miRNA and how does it work?
2. What does the TATA box have to do with RNA transcription and why is it called a "box"?
3. How does RNA polymerase know when to stop transcribing along the template strand?

1. A microRNA regulates genes by binding to some mRNAs & shutting them down.
2. The TATA box is an region of DNA upstream the gene. It consists of T's & A's. It signals the start of transcription.
3. When the polymerase reaches the termination site, the mRNA forms a 'hairpin' structure which releases the polymerase.

All good, for 2 a box is almost like the average nucleotide sequence for each gene, and is calculated using a box layout. Your turn!

[reninkidney]

1. Describe the process of Sanger Sequencing.
https://hihg.med.miami.edu/code/http/mo ... e20403.gif
2. What type of inheritance does this pedigree show?
https://ars.els-cdn.com/content/image/1 ... 11-gr1.jpg
3. What type of mutation does this karyotype show?

[moonwax]

1. Describe the process of Sanger Sequencing.
https://hihg.med.miami.edu/code/http/mo ... e20403.gif
2. What type of inheritance does this pedigree show?
https://ars.els-cdn.com/content/image/1 ... 11-gr1.jpg
3. What type of mutation does this karyotype show?

1. Sanger sequencing starts with a single-stranded DNA template, a DNA primer, a DNA polymerase, normal deoxynucleotide triphosphates (dNTPs), and modified di-deoxynucleotidetriphosphates (ddNTPs), which stop DNA strand elongation. This is because they lack the 3'-OH group required for the formation of a phosphodiester bond between two nucleotides, causing DNA polymerase to stop synthesizing DNA. The DNA sample is divided into four separate sequencing reactions, containing all four of the standard deoxynucleotides (dATP, dGTP, dCTP and dTTP) and the DNA polymerase. To each reaction, only one of the
four dideoxynucleotides (ddATP, ddGTP, ddCTP, or ddTTP) is added, while the other added nucleotides are ordinary ones. The dideoxynucleotide concentration should be approximately 100 times lower than that of the corresponding deoxynucleotide. This makes it so that enough fragments are produced, while the complete DNA sequence is still transcribed. After rounds of template DNA extension from the bound primer, the resulting DNA fragments are heat denatured and separated by size using gel electrophoresis. 2. autosomal dominant 3. deletion in chromosome 15?

[Tailsfan101]

1. Describe the process of Sanger Sequencing.
https://hihg.med.miami.edu/code/http/mo ... e20403.gif
2. What type of inheritance does this pedigree show?
https://ars.els-cdn.com/content/image/1 ... 11-gr1.jpg
3. What type of mutation does this karyotype show?

1. Sanger sequencing starts with a single-stranded DNA template, a DNA primer, a DNA polymerase, normal deoxynucleotide triphosphates (dNTPs), and modified di-deoxynucleotidetriphosphates (ddNTPs), which stop DNA strand elongation. This is because they lack the 3'-OH group required for the formation of a phosphodiester bond between two nucleotides, causing DNA polymerase to stop synthesizing DNA. The DNA sample is divided into four separate sequencing reactions, containing all four of the standard deoxynucleotides (dATP, dGTP, dCTP and dTTP) and the DNA polymerase. To each reaction, only one of the
four dideoxynucleotides (ddATP, ddGTP, ddCTP, or ddTTP) is added, while the other added nucleotides are ordinary ones. The dideoxynucleotide concentration should be approximately 100 times lower than that of the corresponding deoxynucleotide. This makes it so that enough fragments are produced, while the complete DNA sequence is still transcribed. After rounds of template DNA extension from the bound primer, the resulting DNA fragments are heat denatured and separated by size using gel electrophoresis. 2. autosomal dominant 3. deletion in chromosome 15?

I believe #2 is mitochondrial.

[moonwax]

1. Describe the process of Sanger Sequencing.
https://hihg.med.miami.edu/code/http/mo ... e20403.gif
2. What type of inheritance does this pedigree show?
https://ars.els-cdn.com/content/image/1 ... 11-gr1.jpg
3. What type of mutation does this karyotype show?

1. Sanger sequencing starts with a single-stranded DNA template, a DNA primer, a DNA polymerase, normal deoxynucleotide triphosphates (dNTPs), and modified di-deoxynucleotidetriphosphates (ddNTPs), which stop DNA strand elongation. This is because they lack the 3'-OH group required for the formation of a phosphodiester bond between two nucleotides, causing DNA polymerase to stop synthesizing DNA. The DNA sample is divided into four separate sequencing reactions, containing all four of the standard deoxynucleotides (dATP, dGTP, dCTP and dTTP) and the DNA polymerase. To each reaction, only one of the
four dideoxynucleotides (ddATP, ddGTP, ddCTP, or ddTTP) is added, while the other added nucleotides are ordinary ones. The dideoxynucleotide concentration should be approximately 100 times lower than that of the corresponding deoxynucleotide. This makes it so that enough fragments are produced, while the complete DNA sequence is still transcribed. After rounds of template DNA extension from the bound primer, the resulting DNA fragments are heat denatured and separated by size using gel electrophoresis. 2. autosomal dominant 3. deletion in chromosome 15?

I believe #2 is mitochondrial.

oh, yeah ^^;

[reninkidney]

1. Sanger sequencing starts with a single-stranded DNA template, a DNA primer, a DNA polymerase, normal deoxynucleotide triphosphates (dNTPs), and modified di-deoxynucleotidetriphosphates (ddNTPs), which stop DNA strand elongation. This is because they lack the 3'-OH group required for the formation of a phosphodiester bond between two nucleotides, causing DNA polymerase to stop synthesizing DNA. The DNA sample is divided into four separate sequencing reactions, containing all four of the standard deoxynucleotides (dATP, dGTP, dCTP and dTTP) and the DNA polymerase. To each reaction, only one of the
four dideoxynucleotides (ddATP, ddGTP, ddCTP, or ddTTP) is added, while the other added nucleotides are ordinary ones. The dideoxynucleotide concentration should be approximately 100 times lower than that of the corresponding deoxynucleotide. This makes it so that enough fragments are produced, while the complete DNA sequence is still transcribed. After rounds of template DNA extension from the bound primer, the resulting DNA fragments are heat denatured and separated by size using gel electrophoresis. 2. autosomal dominant 3. deletion in chromosome 15?

I believe #2 is mitochondrial.

oh, yeah ^^;

Ok... your turn!