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BIOL 1364 Tutorial 1 (Thursday 4:00-5:00 pm)
1. The basic chromosome number (x) refers to the number of chromosomes that are different and separate from all other chromosomes in that organism. The organism may contain one or more sets of this basic chromosome number. The haploid number (n) therefore refers to a single basic chromosome set and are typically found in the gametes of an organism.
2. Mendel’s principles of inheritance suggests that the inheritance of the traits we possess take place at a molecular level and is brought about by the interaction of two ‘determinants of inheritance’, also known as alleles. Secondly, Mendel suggested that in the event that two different alleles come together, one is expressed while the other is not. The chromosome theory of inheritance describes the chromosome s the basic factor of inheritance. This theory coincides with Mendel’s principles of inheritance in that it shows how chromosome pairs from prophase of meiosis-1 split and migrate to opposite poles and then into separate gametes. Also, this splitting of chromosomes occurred apart from the splitting of the other chromosomes in that cell.
4. Recombination involves the rearrangement of genes by random chromosome assortment and crossing over with occurs during meiosis. Mutations, however, are unprecedented changes in genes which gives rise to entirely new forms of the gene and may occur in any type of cell.
5. Random chromosome assortment describes the random organization of the chromosomes as they split and migrate to their separate poles. Crossing over is the process by which genetic material is exchanged between two chromosomes when certain parts of the chromosomes overlap each other.
6. A gene is the most basic and fundamental unit of heredity whose function is to code for the manufacture of polypeptides which are the backbones of proteins. The locus is the exact location of a particular gene on the chromosome. An allele is a form of a gene.
7. Homologous chromosomes refers to the pair of chromosomes which consist of a chromosome from each parent. They are both made up the same genes but different alleles.
8. The significance of meiosis is to bring about genetic variation among species so that the change of survival is increased.
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