• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Genetic Mutations

Extracts from this document...

Introduction

In genetics, mutation may be small scale (affecting the nucleotide sequence of a gene) or large scale (involving a change in the chromosome). It may arise from faulty deletions, insertions, or exchanges of nucleotides in the genetic material, as caused by exposure to ultraviolet or ionizing radiation, chemical mutagens, viruses, etc. Such a change may result in the creation of a new character or trait. Somatic mutations occur in non-reproductive cells and won't be passed onto offspring. It is recognized that mutations that occur in the body or in somatic cells have no effect on an organism. Most mutations are recognized as 'foreign' by the organism's immune system and are subsequently destroyed. ...read more.

Middle

Melanoma is a cancer which usually starts in the skin, either in a mole or in normal-looking skin. As the mutation took place in a somatic cell the subsequent cancer will not be passed on genetically to the ensuing generation. Most mutations are harmful to the organism concerned. However, beneficial mutations to occur; though they are very rare and they may give a selective advantage to an organism. A mutation that occurs in a germinal cell affects the gametes produced by the organism. In most cases, such mutations wouldn't even be noticed by the individual. However, these mutations, in contrast to the somatic mutations, will be passed on to the next generation, because they occur in the cells that could potentially form a zygote with another gamete. ...read more.

Conclusion

Mendel also studied flower colour in peas, of which there were two distinct phenotypes, purple and white. These are caused by two different alleles of a single gene for color: the purple allele stands for the ability to make purple pigment, and the white allele stands for a lack of ability to form purple pigment, resulting in whiteness. Indeed in general it is often found that contrasting phenotypes are determined by different alleles of a single gene, as Mendel found for petal color. The specific set of alleles carried by an individual is called the genotype, which is the hereditary underpinning of the phenotype. Mendle's research highlighted the colossal differnces a solitary allele can have on the phenotype of an organism; and how such a slight disparity can have extensive effects i.e. colour or height of the organism. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Genetics, Evolution & Biodiversity section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Genetics, Evolution & Biodiversity essays

  1. Investigate how the height to width ratio of Limpets varies with distance from sea

    14 1.2 20.5 -6.5 42.25 52 22 1.2 20.5 1.5 2.25 54 23 1.3 22 1 1 ?d� = 511.5 Statistical Result =1-(6 x 511.5) 233 - 33 = 0.931513 With reference to a statistics guide, I was able to find the critical values to 90%, 95% and 99.9% significance, correct for the number of sites I collated information at.

  2. Recombinant DNA, genetically engineered DNA prepared in vitro by cutting up DNA molecules and ...

    Then, at some time in the future, an event such as virus infection, radiation intake, inhalation of a carcinogen, or cancer-causing chemical, or an imbalance of hormones might free the genes and permit a mature body cell to revert back to an embryoniclike cell.

  1. GENE EXPRESSION

    and operator (negative control). Promoter binds with RNA polymerase before opening the segment of the DNA to be transcribed. The operator (negative control) binds with repressor proteins. Lac operon switches on when two switches are on. One is when lactose is present which induces by removing the repressor protein, the second one is the absence of glucose.

  2. What is the relationship between genotype and phenotype?

    attaches also to the ribosome when a complementary three base codon is present. As the ribosome moves along the mRNA molecule, amino acid sequences occur, in which the monomers are attached via peptide bonds using the enzyme peptydal transferase. The polypeptide chain will grow as various codons bind temporarily with

  1. Oncogenes are genes that cause cancer.

    The most compelling evidence for this conclusion came from the finding that the protein-encoding information of c-src is divided into several separate domains, called exons, by intervening regions known as introns. A split configuration of this kind is typical of animal-cell genes but not of the genes of retroviruses.

  2. dna extraction from peas

    The air bubbles will then carry the DNA to the ethanol layer, which can then be extracted. Results Interpretation The results from this experiment show that the hypothesis stated at the beginning of the experiment is correct. By using a pestle and mortar to break up the peas into

  1. Colour variation in Littorina littoralis on the upper, middle and lower zones of a ...

    This investigation looks to see if this is the case, and if so, will attempt to justify the reasons. If the population of Littorina littoralis were to increase, predators which feed from them will themselves thrive due to the increase in food source.

  2. Investigating the colour variation of Littorina littoralis and their abundance across the upper, middle ...

    An organism which has a phenotype that better suits its environment will generally have an advantage over its competitors. This usually increases the chances of the organism surviving. A desirable phenotype can be anything from a slightly longer or shorter fur length to having slightly longer or shorter limbs.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work