BIO 201 Lecture Notes - Lecture 8: Null Hypothesis, Allele Frequency, Myoglobin

15 views5 pages

yellowgrasshopper324

23 Mar 2016

School

Stony Brook University

Department

Biology

Course

BIO 201

Professor

John Trueand Ross Nehm

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

Document Summary

Three diferent types of nucleoide subsituion mutaions: a mutaion that is not in a coding region. Could change the level of transcripion of a nearby gene if it is in a sequence needed for gene regulaion. Regulatory sequences can be between genes or into introns. Regulatory sequences increase or decrease the level of transcripion of a local gene in paricular cells or condiions. Mutaions that in coding regions: synonymous: does not chance the amino acid. Protein funcion does not change: non-synonymous: changes the amino acid sequence. A pseudogene is a nonfuncional copy of a funcional gene (highest mutaion rate) Variaion at the protein and dna sequence level. In the 1960s-1980s it became apparent that molecular variaion within populaions and species was very common. The idea that natural selecion might have litle or no efect on this variaion came from the above observaion. Many amino acid subsituions might be funcionally equivalent. Don"t change the charge or shape of a protein domain.

Related Questions

Answer these five questions.

1. A non-synonymous substitution is:

a) A mutation that changes the encoded amino acid.

b) A mutation that does not change the encoded amino acid.

c) A substitution of a G with a C or of an A with a T.

d) An insertion of a gene in a genome that substitutes a gene with a non-synonymous gene.

2. If the dN/dS ratio in a gene is smaller than 1, the gene is under selection to change the encoded protein sequence, for example, to evade host recognition.

a) False

b) True

3. A Multiple-locus VNTR analysis compares what between genomes?

a) The number of tandem repeats

b) Non-synonymous mutations

c) Mutation rates

d) SNPs

4. Anthrax is one of the most lethal infectious disease agents we know.

a) True

b) False

5. Why did the CDC not take action to protect postal workers when the second set of letters with anthrax spores were discovered?

a) Because anthrax spores were known to be too large to escape from a closed envelope.

b) Because postal workers did not get infected by handling the first set of letters.

c) Because the CDC misidentified the spores as harmless B. thuringiensis based on an antibody test

d) Because the CDC's mission does not include protecting postal workers from spores of an animal pathogen

greenminnow746

The effect of base-pair substitution mutations on protein function varies widely from no detectable effect to the complete loss of protein function (null allele).

Part A Why do the functional consequences of base-pair substitution vary so widely? Select the four correct answers.

1. Nucleotide substitutions might not cause changes in the amino acid sequence of the protein.

2. The reading frame of the gene could be affected by base-pair substitution mutations, which almost always leads to lack of function.

3. Nucleotide substitutions in exons always lead to changes of amino acids in the protein.

4. The reading frame of the gene could be affected by base-pair substitution mutations, which rarely leads to lack of function.

5. Missense mutations create amino acid substitutions, which might affect protein functionality.

6. Mutations that occur in the intron sequences generally do not affect protein functionality.

bluelion973

1a. which is likely to be more deleterious, a 1bp deletion from an exon in the coding sequence of a gene, or a 3 bp deletion? Explain clearly what all the potential consequences of both deletions could be on the proteins amino acid sequence.

1b. how many different 9-nucleotide mRNA sequences could you make that would produce the peptide tyrosine-leucine-arginine? Assume you are using a cell-free system that does not require a START codon.

1c. imagine you have a single nucleotide substitution (an A has mutated to a G, for example) in an exon of a gene's coding region. It reduces the activity of that gene's protein in your cells to 50% of the usual level of activity. Imagine also that you have a single nucleotide substitution in the same gene's promoter region, and this mutation also reduces the activity of that gene's protein in your cells to 50% of the usual level of activity. Do the 2 mutations reduce the proteins activity level via the same mechanism? Explain your answer.

BIO 201 Lecture Notes - Lecture 8: Null Hypothesis, Allele Frequency, Myoglobin

Document Summary

Get access

Related textbook solutions

Molecular Cell Biology

Biology: Science for Life with Physiology

Concepts of Biology

Biology

Essentials of Biology

Related Documents

BIO 201 Lecture Notes - Lecture 11: Glycoside, Allopatric Speciation, Synonymous Substitution

BIO 201 Lecture 7: Evolutionary Biology since Darwin’s Time

Biology 1002B Lecture Notes - Lecture 23: Nonsynonymous Substitution, Synonymous Substitution, Neutral Mutation

Related Questions