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Mutation

DNA strands contain coded information in the form of nucleotide permutations for the synthesis of proteins.  Nucleotides are composed of a five-carbon sugar, a phosphate group and a nitrogenous base. The four types of bases are complementarily paired together between the two strands, where adenine pairs with thymine with two hydrogen bonds whilst cytosine and guanine pair with three hydrogen bonds. Three nucleotides form a codon, and this corresponds to the production of a specific amino acid – this process is repeated to produce a chain of polypeptides or proteins. Mutations are changes to the base sequence of the nucleotides which ultimately affect protein synthesis – this can lead to phenotypic disorders and conditions. If a changes in base sequence occurs it can have no effect on the overall organism, or it can be classified under four types of mutations: substitution, insertion, deletion and frameshift.

Substitution mutations occur when one base is swapped with another, e.g. an adenine is replaced by guanine, this can change the amino acids in proteins. There are three types of substitution mutations: silent, missense and nonsense. A silent mutation is when a change in a base has no impact and the same amino acid is produced from the codon – this occurs because there are many codons that code for the same amino acid. Missense mutation is when a substitution occurs and produces a different amino acid, which can be beneficial or detrimental to overall protein function. Nonsense mutations are when a base is substituted with another to create a stop codon, this produces an incomplete protein.

Insertion mutations are when extra base pairs are added to the sequence, this can have the effect of adding stop codons to produce incomplete proteins. Deletion mutations are when portions of the base sequence are deleted which then certain genes are not expressed leading to genetic disorders. Frameshift mutation is when a combination of insertions and deletions of the base sequence occur, the sequence is no longer divisible by three and it changes the codons, amino acids and proteins expressed.  

Scientific method for genetic studies

I have attached the full question, but in summary, it asks that I use scientific method to explain which genes are recessive and which are dominant.

Meiosis, independent assortment

Eukaryotic cells can divide by mitosis or meiosis. In humans, mitosis produces new cells for growth and repair; meiosis produces sex cells (gametes) called sperm and eggs. Although mutations are the ultimate source of genetic variability, both meiosis and sexual reproduction also can contribute to new genetic combinations in of

Genetics and mutations

1. What is the difference between genotype and phenotype? 2. What is the difference between haploid and diploids? 3. What is the difference between a null mutation and a conditional mutation? 4. What are the two types of conditional mutations? 5. What is the difference between a genetic selection and a genetic screen? 6.

Mutation and DNA Extraction

DNA & RNA Procedure 1: 10.In "C" we mutated one letter. What role do you think the redundancy of the genetic code plays, in light of this change? 11.Based on your observations, why do you suppose the mutations we made in "D" and "E" are called frame shift mutations. 12.Which mutations do you suspect have the greatest

DNA Mutation

A particular DNA mutation produces a UGA stop codon in the middle of the RNA coding for a specific protein. A second mutation in the cell causes a single nucleotide change in a tRNA that enables the correct translation of the protein - meaning, the second mutation suppresses the defect caused by the first. What nucleotide change

Genetic Diseases of Alzheimer's or Ovarian Cancer

I just need some help in putting this paper in terms that are used for genetic diseases like Alzheimer's or ovarian cancer. My mom and brother both died of cancer, also I had two friends die of Alzhiemers. I do not know what causes either disease or what could have been done to prevent it from happening. Since two of my family m

Mistake in DNA Replication Resulting in Mutation

How would a mistake in DNA replication resulted in a change in a amino acid (His 208 Tyr) of the Mc1r protein from a hisidine to a tyrosine in Sceloporus undulates, resulting in lighter skin? I think perhaps a mistake could be during DNA replication, or perhaps a change in the mRNA sequence, but Im not sure about the in's and

Biomolecular science.- DNA SEGMENT

ATAGCCCGGGGGTTTAAA TATCGGCCCCCAAATTT 1)figure out what amino acids will be joined to make the protein coded for by this segment of dna if the bottom strand is used to make the mRNA. 2)Make a mutation in the dna sequence by changing only one base pair that you expect might have an affect on the protein that is made. 3

Cystic Fibrosis and Point Mutations

If both parents must have a point mutation in their CF genes in order to create a child with CF, how common do you think the disease is in the population? Explain. Why do you think another mistake doesn't just "correct" the mutation in an abnormal CF gene? What do you think the chances of this occurring would be? Compare this

Gene Mutation

1. Give a brief description of each of the following: a.heritable mutation b.nutritional mutation c.conditional mutation 2. a.Write a wild-type DNA sequence with 10 bases and under it write the sequence after a transversion and a transition has occurred. Underline and label both mutations. b.Write a DNA sequence of 1

Genetic / Evolution

The blood disease beta-thalassemia results from homozygosity for a defective allele in the gene coding for the beta hemoglobin subunit. Homozygotes for the beta-thalassemia allel die in childhood, while heterozygotes appear normal. This disease is common in the region around the Mediterranean sea, including the island of Sardini

It's regarding mutations

a student in a molecular genetics lab is using the SSCP technique to analyze DNA from breast cancer tumours and has identified five different shifts in fragments of the BARD1 gene. (BARD1 [genbank accession number NM_000465] is a tumour suppressor gene, mutations in which are associated with breast cancer.) Partial sequences fr