A mutation is referred to as an alteration in the structure of a gene or chromosome. There are several types of DNA. They include deletions, insertion, duplications, and rearrangements of DNA. Insertion mutation enable the extra base pairs to be inserted in the DNA. As a result, the protein produced by the gene may end up not functioning well. Deletion mutation, on the other hand, is a mutation that modify various DNA bases particularly by eliminating some piece of DNA. However, deletions might remove one or few base pairs within the gene. According to Schaaf, Zschocke and Potocki (2012), the deleted DNA may change the function of the resulting proteins. Deletions which are higher tend to remove an entire gene in the DNA. Lastly, base substitution is whereby one base is exchange from another. However, a change in a codon converts amino acids and does not varies the amount of protein produced.
Insertion mutation mostly occurs when an extra nucleotide is added to the DNA constituent when replication is carried out. It happens when the replicating constituent Wrinkles or “slips” that allow an additional nucleotide to be incorporated. On the other hand, a deletion mutation occurs when a wrinkle is formed on the DNA prototype constituent and afterward causes a nucleotide to be removed from the replicated strand. For example, in a top sequence, there are three nucleotides that comprise a single codon that are deleted. This tends to shorten the end product by one amino acid but it does not affect the whole sequence. However, in the lower section, one single nucleotide is deleted. In addition, Insertion and deletion mutations also have a distinct effect on the coding capabilities of genes. For instance, if the number of inserted or deleted nucleotides is three or multiple of three, then one or more codons are added or removed. This result to loss or gain of amino acids that have varying effects on the function of the encoded protein. On the other hand, if the number of inserted or deleted are not three or multiple of three; then a frameshift occurs. A base mutations is a type of mutation that normally replace one base with another. Since the genetic code is inessential, some substitutions will have no effect at all. For example, a base substitution of a uracil for a cytosine in the codon CCU might have no effect on the protein produced as both CCC and CCU code for proline.
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Polyploids are organisms that have multiple sets of chromosomes more than the diploid number. It is very common in nature and provides a major mechanism for specification and adaptation. Some of the plants that are polyploids include tomato, potato, coffee, and banana among many others. Polyploids arise from the result of total nondisjunction of chromosomes, particularly during meiosis and mitosis. According to Hancock (2012), the production of polyploids had low fertility rates as compared to their diploid prototypes. Generally, there is an optimum range of polyploidy beyond the growth that may be depressed particularly with increasing numbers of chromosomes. Polyploidy plants have two basic advantages; heterotic and gene redundancy. This two are as a result of gene duplication. Polyploidy plants also overcome sterility, induce sterility, have seedless fruits, have stronger progeny, and play a major role in Speciation. Polyploid is more common in plants than animals since plant breeders utilize this process in treating desirable hybrids with chemicals which are commonly known to induce polyploidy. Contrary, polyploid animals are far less common, and the process seems to have a little effect on animal speciation.
References
Hancock, J. F. (2012). Plant evolution and the origin of crop species . Wallingford, Oxfordshire, UK: CABI.
Schaaf, C. P., Zschocke, J., & Potocki, L. (2012). Human genetics: From molecules to medicine . Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins Health.
