BIS 2A Chapter 15: Chapter 15 Mutations

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tanwolf263

22 Sep 2015

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>somatic mutations: occur in body cells and are passed onto daughter cells during mitosis. >germ line mutation: occur in cells of the germ line specialized cells that give rise to gametes: silent mutations don"t usually affect protein function. It can be a mutation in the region of dna that doesn"t encode a protein or it can be in the coding region of the gene but not affect amino acid sequence. It results in genetic diversity that don"t express phenotypic differences. Could affect mrna stability or affect rate of translation because differences in abundance of specific trnas. Loss of function mutation affects protein function. It can cause a gene not be expressed or expressed but protein no longer plays its cellular role. Usually shows recessive inheritance in diploid organisms: gain of function mutation leads to a protein with an altered functions.

Related Questions

Scientists have been studying the effects of Starkagaren Disease, which is regulated by the stgn gene, in cultured normal and breast cancer cell lines. They have fused a yellow fluorescent probe to the end of the stgn gene to study the disease more closely. By adding a probe, it will create a hybrid protein that emits a yellow color under a blue laser. This hybrid protein is known as a fluorescentâtagged protein, meaning that the protein itself will function and fold normally but it will be tagged with a yellow fluorescent probe (YFP) at the end. This allows the scientists to follow the protein through the cell cycle. They find that the stgn protein normally binds to centromeres in normal cells. After looking at cells at various stages of the cell cycle, they find that compared to normal cells, the breast cancer cells that express the Starkagaren Disease display abnormal nuclei, some appear very large, some have tiny nuclei, and some cells do not have a nucleus at all.

Scientists have figured out that Starkagaren Disease is passed on through a mutation in the germ cells. The mutation is found on the chromosome 12 so either the mother or father can pass on the gene. But in order for the disease to express, both parents need to have the mutation. You are a genetic counselor talking to two individuals that have familial history of either a grandparent or aunt or uncle with the disease, they would like you to explain their chances of having a child that could possible inherit the disease.

a) Would the defect be found in homologous chromosomes or sister chromatids, or both? Explain.

b) If the location of the gene with the defect is found near the tip of the chromosome, how likely would that defect transfer to a homologous chromosome? Explain how it may or may no occur.

viridiansardine993

Part B

Think about the DNA coding sequence of a gene. If an A were swapped for a T, what kind of mutation could it cause and why?

a) It could cause a frameshift nonsense or frameshift missense mutation because it would change the reading frame of the codon triplet.

b) It could cause a silent, missense, or nonsense mutation because those are the types that can be caused by a nucleotide-pair substitution like this one.

c) It could cause a nonsense mutation because the sequence would no longer be the same, so the protein would be shorter and non-functional.

d) It could cause a silent mutation because A and T are complementary to each other so it is not really a substitution mutation.

Part C

Why is a frameshift missense mutation more likely to have a severe effect on phenotype than a nucleotide-pair substitution missense mutation in the same protein?

a) A substitution missense mutation causes the protein to be shorter and thus non-functional.

b) A frameshift missense will cause the codons to be out of order, but a substitution missense does not change the order of the codons.

c) A frameshift missense mutation will cause an early Stop codon, but a substitution missense might be silent.

d) A substitution missense affects only one codon, but a frameshift missense affects all codons downstream of the frameshift.

Part D

Which of the following sequences shows a frameshift mutation compared to the wild-type mRNA sequence?

a) wild-type	5â-AUGCAUACAUUGGAGUGA-3â
mutant	5â-AUGCAUACAGAGUGA-3â

b) wild-type	5â-AUGCAUACAUUGGAGUGA-3â
mutant	5â-AUGCAUACGUUGGAGUGA-3â

c) wild-type	5â-AUGCAUACAUUGGAGUGA-3â
mutant	5â-AUGCAUACAUCUGGAGUGA-3â

d) wild-type	5â-AUGCAUACAUUGGAGUGA-3â
mutant	5â-AUGCAUGUGACAUUGGAGUGA-3â

Part F

Suppose that the triplet of nucleotides indicated in bold (AGC) spans two codons, that is, CTA and GCC. If the triplet AGC were deleted from this DNA coding sequence, what effect would it have on the resulting protein?

5â-ATGCTAGCCTATCGTAAC-3â

a) The two flanking codons would be altered, but the rest of the amino acid sequence would be the same because there would be no frameshift.

b) The entire amino acid sequence would be altered due to the frameshift.

c) All of the amino acids after the deletion would be altered due to the frameshift.

d) All of the amino acids up to the deletion would be altered due to the frameshift.

mauvetrout554

Which of the two major categories of the chemical reactions in photosynthesis is oxygen the INDIRECT product?

Glycolysis

Oxidative phosphorylation

Both light and dark

Light independent phase (LIP)

Light dependent phase (LDP)

You have a stomach flu characterized by vomiting. Which of the following systems is most responsible for the food in your stomach going the wrong way, e.g. vomiting? (Disregard this question and answer choice B)

Cardiac Muscle in the large intestine as discussed in class.

Smooth muscle in the gastrointestinal tract

Smooth muscle in the blood vessels

Skeletal muscle in the intestine

Proteins are made from which of the following smaller sub units?

Nucleotides

Amino acids that cannot enter the blood stream and go to cells

Monosaccharides

Fatty acids

Amino acids which can form new protein

Carbohydrates are digested in the gastrointestinal system into which of the following substances that is the smallest structure?

Polysaccharides that are produced by glucagon

Monosaccharides that are produced by insulin

Monosaccharides

Polysaccharide

Which of the following biomolecules has the longest digestion time? In other words, how long does it take for the biomolecule to be catabolized?

DNA

Lipid

Carbohydrate

Protein

You are sunburned after a long day at the beach. Which one is not an example of UV damage to your skin cells?

A mutation can occur in your ovaries

A mutation can occur in skin cell DNA that can lead to errors in transcription.

Errors can occur during DNA replication.

UV light can cause mutations in DNA of skins cells.

Thymine bases in your skin DNA bond with each other instead of across the double helix

This region, the ______________ (a) tells RNA polymerase where to bind to DNA while this region, the ______________ (b) tells RNA where to start transcription.

(a) promoter, (b) open reading frame

(a) start codon, (b) methionine

(a) promoter, (b) start site

(a) start site, (b) promoter

The genetic code is used to translate ______________ into ______________.

lipids, nucleotides

nucleotides,carbohydrates

nucleotides, lipids

nucleotides, amino acids

nucleosides, amino acids

Transcription of a gene has just completed. What are the next steps (in the correct order) to complete expression of that gene?

RNA polymerase makes a copy of DNA into mRNA.

mRNA is translated in the nucleus and ribosomal RNA moves into the cytoplasm.

Gene expression is completed after transcription.

mRNA moves into the cytoplasm and with tRNA they interact to form protein

Translation machinery moves into the nucleus and mRNA is translated into protein.

How is it that a mutation in DNA stored inside the nucleus of a cell can cause a disease affecting multiple organs?

This remains an unanswered question in science that scientists are still trying to figure out.

The mutated DNA is expressed in multiple cells through the process of transcription and translation, and the altered protein causes the disease wherever the DNA was expressed.

The mutated DNA is expressed in one cell and the altered protein travels to multiple organs to cause disease.

The mutated DNA is expressed and the mRNA takes the mutated information to other cells where the altered protein is made to cause disease in that organ.

The advantage of sickle cell anemia is which of the following?

It decreases the amount of oxygen in the blood cells so that mosquitoes carrying malaria will live

It decreases the amount of oxygen in the blood cells so that mosquitoe's blood form will die.

It allows the blood vessels to decrease the amount of blood going to the toes and feet.

There is none.

Which of the following is a purpose of cell division?

Cell reproduction

Growth

Repair

All of these

BIS 2A Chapter 15: Chapter 15 Mutations

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