MCB 10 Lecture Notes - Lecture 13: Aniridia, Haemophilia A, Achondroplasia

48 views2 pages

periwinkleturtle622

25 Sep 2016

School

UC-Davis

Department

Molecular and Cellular Biology

Course

MCB 10

Professor

Bruce Rannala

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Lecture 13 dna mutation and repair: the nature of mutations, mutation a change in a dna sequence, a mutation may occur at the dna or chromosome level. Polymorphism a genetic change that is present in > 1% of a population. Gain-of-function mutations dominant: germline mutations originate in meiosis; affect all cells of an individual, mutations alter proteins. Somatic mutations originate in mitosis; affect only cells that descend from the changed cell. Identifying how a mutation causes symptoms has clinical applications. Examples of mutations that cause disease: beta globin gene, collagen genes: mutations may occur spontaneously or by exposure to a chemical or radiation, mutagen an agent that causes a mutation, spontaneous mutation. Spontaneous mutation rate differs between genes: mitochondrial genes mutate at a higher rate than nuclear genes because they. Each human gene has about 1/100,000 chance of mutating. Each individual has multiple new mutations cannot repair their dna: determining mutation rate.

Related Questions

2. Letâs consider transport of iodine (I- ) into your thyroid cells. You need iodine in your diet for normal thyroid activity, but dietary iodine concentrations are very low (usually in America we get enough just from what is added to iodized salt). People have been interested for some time in trying to figure out how we can transport iodine so efficiently. One way we can study the transporter is to look for mutations that alter its function, and therefore lead to thyroid problems.

A. The transporter is a rocker-switch type Na+ / Isymport. The pivot of the rocker mechanism is a glycine amino acid, #93 in the primary structure of the transporter. Some people with thyroid problems have a mutation that changes this glycine to an arginine. Define what is meant by âthe primary structureâ of the transporter. Explain how that change would alter the function of the transporter. (You may consult the structure of arginine on slide 7 of Lecture 3.)

B. There is normally an Arginine at position #124 in the primary structure of the transporter. This Arginine participates in hydrogen bonding with an Asparagine, positioned at #441 in the primary structure. There is evidence that these H-bonds are present in the outward-facing transporter conformation, but are broken when the transporter switches to the inward-facing conformation. People with mutations that replace Arginine 124 with Histidine have difficulty transporting Iodine into their thyroid cells. Copy the structures of Arginine and Asparagine. Label relevant H-bond donor and acceptor atoms between these two amino acids. Explain how replacing Arginine 124 with Histidine could affect the operation of the transporter. (Make a sketch of the transporter in the inward-facing and outward-facing conformations to help you to visualize this.)

C. Recent investigation demonstrated that there are actually TWO Na+ ions symported with the Iion. When a colleague of mine saw this report, he said âAh ha! So thatâs why iodine transport is so efficient!â Explain why it would make a difference whether one or two sodium ions were involved? Why would involving two sodium ions make the transporter more efficient?

(tautomerization) The most common form of guanine is the ketoform, not the enol form.

True

False

What term describes the allowed degree of base pair matchingduring annealing, varying from lots of base-pair mismatches allowedto allowing only perfect base-pair matching.

stringency

aneuploidy

polyploidy

quantitative PCR

restriction fragment length polymorphism

I have an individual with a disease we will call SSI-itis,brought on by extreme exposure to cannabis. I do a southern andfind the gene affected. Another of his classmates exhibits theexact same symptoms, but that gene in hiw is wt. A southern in thesecond student finds a mutation in another gene. This is an exampleof

pleitropy

allelic heterogeneity

locus heterogeneity

dominant traits

recessive traits

penetrance

If a person carrying a dominant allele does not demonstrate thephenotype strongly, but still differs from wt, thisdemonstrates?

haploinsufficiency

penetrance

expressivity

monogenic traits

polygenic traits

I find three alleles for a gene in a fruit fly. One allelecreates the ability for the fly to eat graphite. Another allelecreates the ability for the fly to eat coal. The third alleleallows the fly to eat diamond. These alleles are all dominant, andwt cannot eat any of these substances. Which statement below is themost true?

Upon mating a bunch of the flies carrying these alleles, Ishould not find a fly that can eat graphite, coal, and diamond.

I would consider the ability to eat these substances an exampleof pleitropy because they are all carbon.

I would expect the ability to eat diamond to be dominant to theability to eat graphite.

These flies are demonstrating locusheterogeneity.

Expression vectors in prokaryotes do not make functionaleukaryotic gene products in bacteria very well because

the codon sequence for prokaryotes is different than the codonsequence in eukaryotes

there are no disulfide bridges formed in proteins normally madein prokaryotes

prokaryotic expression vectors cannot translate eukaryticsequences

eukaryotic genes have introns, and prokaryotes don't

eukaryotic genes have exons and prokaryotes don't

Which of the following is not used in PCR amplification ofDNA?

Double-stranded DNA template

Oligonucleotide primers

DNA polymerase

DNA ligase

ddNTPs

I create a knockout mouse using the agouti/black fur systemdiscussed in the online lecture and in the book. When I cross theagouti offspring of the originally engineered mouse, I find a ratioof 2 agouti mice to 1 black furred mouse. What is the bestexplanation?

The gene knocked out was recessive.

The gene knocked out was dominant.

The gene knocked out was a lethal gene.

The knockput was integrated into a random spot, and did notknockput the original gene.

A loss of function mutation is usually recessive, but canactually be a dominant mutation because of what effect?

haploinsufficiency

dominant negative mutations

allelic heterogeneity

locus heterogeneity

pleitropy

A genetic carrier of a disease can have a form of the diseasethat only shows intermittent symptoms, while the full homozygousrecessiuve individual would show all of the symptoms of thedisease.

True

False

Wild type, or wt, refers to the genotype that is the typicalgenotype found in nature. Now read that again. Once more. Nowanswer.

Answer

True

False

mauvekangaroo793

MCB 10 Lecture Notes - Lecture 13: Aniridia, Haemophilia A, Achondroplasia

Document Summary

Get access

Related Documents

MCB 10 Lecture Notes - Lecture 14: P53, Tumor Suppressor Gene, Fusion Protein

MCB 10 Lecture Notes - Lecture 6: Myopathy, Gamete, Genetic Linkage

MCB 10 Lecture Notes - Lecture 3: X Chromosome, Capacitation, Metaphase

Related Questions