Gene Mapping in Ascospore Sordaria Cultures by Recombination

C-Fern plants are a strain of Ceratopteris richardii and have a rapid reproductive cycle, making them perfect subjects in lab to be tested and observed on population genetics. Population genetics is the study of genetic variation and allelic frequencies on a specific group over an amount of time. It is a great way to predict future genetic information on more than just the C-Ferns. In this experiment, two different generations for gametophytes and sporophytes of C-Ferns were observed and counted for the amount of wild type and polka dot mutant individuals within a sample and a population. The overall results demonstrated a 1:1 ratio of mutant to wild type in the F1 gametophyte generation for both the sample and population, which was expected. The F1 sporophyte generation demonstrated a 1:1 ratio of mutant to wild type in the sample and a 2:1 ratio of mutant to wild type in the population. A 3:1 ratio of mutant to wild type was expected in the sporophytes. It was concluded that the polka dot mutant is recessive in sporophytes and demonstrates random fertilization in the diploid stage, but not in gametophytes. This process of population genetics in C-Ferns can be extremely beneficial in other organisms, such as humans. Population genetics could be a tool in medicine in determining human

Meiosis consists of one DNA replication and two nuclear divisions resulting in 4 daughter cells. The process which provides for genetic variation is crossing over. Crossing over occurs in the early stages when homologous chromosomes move together so that their chromatids form a tetrad. This is called synapsis and allows for the exchange of chromosome sections.

Mitosis and meiosis are similar in several ways and different in others. The similarities include that both processes involve IPMAT. IPMAT is interphase, prophase, metaphase, anaphase and telophase. The parent cells are diploid. They both end with cytokinesis. In Metaphase and Metaphase II, the sister chromatids line up along the center. Then in Anaphase and Anaphase II, these chromatids are split and pulled towards the centrosomes. The differences are that mitosis consists of 1 division while meiosis consists of 2. Four genetically different, haploid sex cells are the products of meiosis and 2 identical, diploid somatic cells from mitosis. Mitosis occurs in all organisms except viruses and meiosis only occurs in plants, animals, and fungi.

The combinations of 4:4, 2:2:2:2, and 2:4:2 can arise through crossing-over (Burpee et al., 2015). A 2:2:2:2 and 2:4:2 combination indicates crossing-over while 4:4 signifies the recombination did not occur. This process occurs during prophase I of meiosis between Wild Type and Tan isolates crossing-over (Burpee et al., 2015). It was initially thought that recombination was random; however, research from the Evolution Canyons shows that S. fimicola is, indeed, affected by the environment (Burpee et al., 2015). This could possibly be from radiation; however, research in this area is sparse. Certain species of fungi have shown increased resistance to radiation (Saleh, Mayo, & Ahearn, 1988), but studies on S. fimicola have not been documented. Based on this information, I hypothesize that when S. fimicola isolates are exposed to X-ray radiation the crossing-over frequency will increase. To test this theory one Tan and one Wild Type sample (with different combinations of x-ray radiation) was placed in a petri dish diagonal from each other. This was repeated to create four quadrants. The S. fimicola isolates were incubated for two weeks to produce perithecia (Burpee et al.,

Subcloning of fungal cDNA from pBK-CMW into a plasmid vector pUC19 using fungal gene CIH   Introduction A plasmid is a circular, double stranded DNA molecule that replicates independently of the chromosome DNA within a cell.pUC19 is one of the most commonly plasmid cloning vector used due to its high copy replication number (approx. 100 copies per cell), ampR (ampicillin resistance gene) andterminal fragment of β -galactosidase (lac Z). It is circular double stranded and it has 2686 base pair length from which 54 are multiple cloning sites polylinker that contains unique sites for specific restriction endonucleases.

2. a) How does meiosis introduce genetic variation into offspring? Think about how the chromosomes line up.(1 point)

For one of the monohybrid crosses you performed in this Investigation, describe how to use the phenotype ratios to determine

The purpose of this experiment was to measure the T4 reversion rate to wild type combination, and the recombination frequency recombination frequency of the T4 mutants to the wild type. Also to determine the distance between the two mutants, which are T4 rII 29 and T4 rII 31.

Define the term crossing over. (3 points) During meiosis’ prophase the homologous chromatids exchange segments.

Meiotic errors are alterations of a cell's chromosome number or structure. Chromosomal alterations happen in both mitosis and meiosis. But in other ways meiosis provides more opportunities for errors. Do to the three sources of genetic variation in meiosis that can also be opportunities for errors. Crossing over in prophase I independent assortment and in anaphase I and anaphase II are major sources of genetic variation in the sexually

Part B: Genes X, Y, and Z are linked. Crossover gametes between genes X and Y are observed

The two bands are due chromosome pairing, one contains a retrovirus in that section, the other does not (heterozygous).

You are also provided with a heterozygous female, and a homozygous recessive male for a genetic cross. In this particular female, all the dominant alleles are on one chromosome, and the recessive counterparts are on the other homologous chromosome. Due to a chromosomal condition, in the female no recombination occurs between the M and N loci. Normal recombination occurs between the L and M loci. Diagram this cross, and show the genotypes and frequencies of all offspring expected from this cross.

Our results had been inconclusive in this part of the lab. The unknown was run with the other class due to the loss of a PCR tube. The tube had been redone and run in the gel and results had been inconclusive. No results had been shown for our gel. Meaning something along the way had been done incorrectly and as a result the experiment had no results. It is possible that primers or something was not added to the tube causing failed results. A wide variety of things could have gone wrong. But what we do know is that results should have occurred. In figure #6 the gel that was done by our class we could see that there are results. There is a very noticeable band that shows that this experiment could be done and that it wasn’t any machines fault but human error. The class had a band around 1500 base pairs which would be completely correct because 16s rRNA gene is usually 1500 base pairs long (Clarridge

In meiosis the pairs of chromosomes (that code for possible outcomes of characteristics) temporarily join and exchange information (crossing over) creating different combinations of gene types (alleles). For example; a pair of chromosomes could be a dominant allele (gene type) and a recessive allele which might code for brown hair. After crossing over it might be recessive which could be blond hair.