Ploidy

Meiosis is the process in which a diploid cell is divided into 4 haploid cells. Meiosis is separated into two parts meiosis I and meiosis II. In meiosis I, the first step is interphase and in this phase DNA is replicated. For example, in the diagram the DNA of big A, small a, big B, small b will all be replicated. This will create a doubling of the DNA that existed and will later be condensed into chromosomes. After interphase, prophase I occurs; in prophase I the replicated chromosomes pair up with their homologous pairs and this creates a tetrad that is formed by the sister chromatids. The sister chromatids were the homologous chromosomes before being paired up. In reference of the last example, the replicated big A will pair up with the original big A to form the tetrad. The big A and the replicated big A are now sister chromatids rather than homologous chromosomes. However, only when two chromosomes are paired up the chromosomes can be called sister chromatids. For example, big A and small a are not considered sister chromatids. During this step, a process named crossing over occurs. Crossing over creates genetic diversity among the chromosomes. This process is where two chromosomes exchange parts of their genetic information with each other. The region of exchange is called the chiasmata. For example, when big A and small a are paired up segments of small a can be exchanged with segments of big A. This also occurs with the big B and small b chromosomes. The next step is…

In the four-week long experiment conducted in the Bio 13 Lab, we were able to conduct a genetic analysis of the yeast S. cerevisiae, particularly investigating the inheritance and linkage of three genes: HIS4, LEU2, and LYS2. In week one, a suspension of spores was received and aliquots of the suspension were plates onto two YPD plates. After a week of yeast growth, haploid spore clones were carefully picked from the plates by sterile toothpicks and used to make patches on a new YPD plate, the…

Purpose and Background Cells divide in two ways, mitosis and meiosis. Mitosis is used to produce cells that are genetically identical to the parent cell for growth, asexual reproduction, or repair after injury. Cells that are produced by mitosis are diploid, meaning that they have two complete sets of chromosomes, one from each parent. Meiosis is used to produce haploid cells that have only one set of chromosomes, a mix of chromosomes from both parents. Meiosis produces cells that are…

This prepares the genetic material for directing the metabolic activities of the new cells. The spindle breaks down and new nuclear envelope forms. Interphase is when the cell is no longer actively splitting. In contrast, meiosis gives rise to four unique daughter cells, each of which has half the number of chromosomes as the parent cell. Because meiosis creates cells that are destined to become gametes this reduction in chromosome number is critical. The stages are prophase I, metaphase I,…

and Dicot Seed Structure • A red bean seed and corn seed was obtained. • The skin of the red bean was removed and the bean was carefully separated in half to prevent damage to the embryo. • A diagram was drawn to show the visible structures. • A drop of iodine was placed on the inner surface of each seed and results observed were recorded. Angiosperm Fruits • The structures of difference types of fruits were observed from text (Biology by Solomon Martin Berg). • Pictures showing external and…

possible risks that it may carry. This is especially true for technologies that affect our food supply. It is important when evaluating the threat of such risks to distinguish the difference between actual potential risks and scare-stories spread by misinformation, misinterpretation, or sensationalism. As such, in my summary of the benefits and risks of genetically modifying crop species I will ignore those risks and worries that have been proven to be insubstantial. The Advantages of GM Crops…

genomic hybridization microarrays’ are used to compare DNA from a control sample to a biopsy sample and detect imbalances in chromosomes (Herrera, 2016). A single nucleotide polymorphism (SNP) is the most frequent type of variation in the genome and is the second way of microarray is used (Herrera, 2016). In SNPs microarrays, the DNA sample hybridized and then analyzed to determine phenotypes of the embryo. The benefits to SNPs include being quick and ability to enhance accuracy of PGD…

basidia of α mate types of serotype C and D. Both forms abundant filaments but the differernce noticed in the shape of basidiospores. Serotype C yeast forms smooth rod shaped spores while serotype D forms lemomn shaped spores. Campbell LT et al (2005) have analyzed a total of 120 C. gattii isolates from environmental, human and veterinary sources using the tester strains (as used by Fraser JA et al, 2003) (Table no. 9). For observation of mating they have used Differential interference contrast…

they are Polymerase Chain Reaction (PCR) ,Fluorescent in situ hybridisation (FISH) and Comparative genomic hybridisation (CGH) – new technology . According to Wikipedia Polymerase chain reaction (PCR) is when technology and molecular biology is used to reduce one or a few copies of particular part of DNA across different orders of magnitude and generating thousands and millions of copies of a certain DNA sequence Fluorescene in situ hybridization (FISH) is a when they use fluoresecent probes…