• 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

    The height: width ratio of Limpets does increase with distance from the sea and my results support this conclusion. As a general trend the width of the Limpet shell will not exceed its height. Due to the rocky shore being sheltered, the height: width ratio increased which indicates that the shells are taller rather than wider.

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

    A membrane does this by providing molecular "turnstiles" that regulate which molecules can enter and which cannot. Still another function is fulfilled by a membrane: it houses some of the cell's enzymes as well as its energy-converting "machines." The membrane enzymes, which are special proteins themselves, carry out respiration needed

  1. Oncogenes are genes that cause cancer.

    The chicken lymphoma viruses have no oncogenes. Why then do they cause tumors? William S. Hayward and Benjamin G. Neel of Rockefeller University and Susan M. Astrin of the Institute for Cancer Research in Fox Chase, Pa., have discovered that in tumors induced by the chicken lymphoma viruses the viral

  2. What is the relationship between genotype and phenotype?

    RNA then leaves the nucleus via a nuclear pore and attaches to the small subunit of a ribosome (rRNA + proteins), exposes 6 bases (2 codons or triplet codes) to the large sub-unit. Transfer RNA, consisting of a single stranded yet folded RNA molecule, together with an anticodon and attached to a specific amino acid (using energy from adenine triphosphate)

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

    Another possible outcome is that the organism does reproduce, and so its offspring display the same undesirable phenotype and have the same decreased chances of survival. This process leads to desirable phenotypes becoming more common and undesirable phenotypes becoming less common.

  2. What different methods exist for studying genetic variation at a molecular level? How could ...

    Distinguishing between two types of non-coding polymorphs allows us to determine how these variations can be practically established among individuals, and why such an exercise is applicable in modern genetics. A restriction endonuclease is derived from bacteria that utilise the enzyme to disintegrate the genetic material of invading bacteriophages which are parasitic.

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