Haploid and Diploid Cells, Mitosis and Meiosis - Assignment Example

Write short paragraph answers in your own words for the following questions What are haploid and diploid cells and how does the process of fertilization produce a diploid cell? According to Armstrong (2007), the haploid cell is that containing two complete sets (2n) of identical chromosomes while on the same breath, diploid cells are those having half the number of cells as diploid that is they contain just one complete set (n) of chromosome in the nucleus. A diploid cell is a result of meiosis (a special kind of cell division) and the fertilization of a haploid egg and haploid sperm from diploid parents.

From this, diploid zygotes containing both maternal and paternal chromosomes are formed. With each set coming from either parent. The diploid zygote undergoes mitosis to form a diploid organism (Armstrong (2007). 2. Describe the similarities and differences between mitosis and meiosis. Some of the differences between mitosis include but are not limited to, mitotic cells dividing once whereas meiotic cells divide twice. Mitosis results in cell replication with meiosis, genetic recombination, and production of reproductive cells being the sole aim.

Mitosis doesn’t yield exact copies whereas meiosis does. Mitosis also gives rise to diploid cells while meiosis gives haploid cells. DNA crossover occurs only in meiosis (Armstrong, 2007). As for similarities, duplication of an organism’s genome takes place only once preceding any other duplication in both processes. There existence of metaphase plates, and centrioles in both (Armstrong, 2007). The basic steps of division are the same for both. Mitosis and meiosis occur both in eukaryotic cells.

Finally, both represent reproduction processes. Genetic ProblemA wild population contains tall and short plants. In one cross, two parental tall plants yield all tall progeny. In another experiment, two short plants are crossed and all progeny are short (cross 2). In the third experiment (cross number 3), two different short plants from cross 2 are crossed and 23 tall progeny and 77 short progeny are observed. Explain the observations, give the most probable genotypes of the parents and progeny of each cross, and identify which are dominant and recessive.

Cross 1Parental Genotypes TT × parental gametes T and tF1 Genotype=All tall offspring (Tt)The F1 generation came about through the selfing of F1 plants. While maintaining Mendel’s first law, the law of segregation, where the gamete is formed when each member of the allelic gets disjointed from their other member. Confirmation of the accuracy of his law through selfing of F2 plants yielded all tall and short plants respectively (Tornqvist, 2006). This can be depicted using a Punnet square as depicted on the next page.