Meiosis

Our interest in the topic of Down syndrome (Trisomy 21) started when we heard about how many people are affected by this disease. The number of people affected by this disease in the United States alone is around 400,000 people. This genetic disorder is caused when a person is born with an extra copy of chromosome twenty-one. Down syndrome is recognized by things such as short stature, a distinctive palm crease, stubby fingers, mental retardation that can end up being serious, a wide gap between…

Evolving our Genetic Ideas Evolution was a recognized theory long before heredity was properly understood, however, Darwin has allowed us to understand human evolution to a far greater extent than he would have ever imagined. Genetics can be expressed in many different ways. The more often a specific phenotype is observed within the population may relate to how favourable that phenotype is for survival. This is because of relative frequency and lethality. Relative frequency is the number of…

Antibiotics are a medicine that inhibits the growth of or destroys microorganisms that cause infections and diseases. Since the drug 's inception in 1929 we have seen a dramatic reduction in deaths caused by infection and many other bacterial based diseases. Antibiotics have increased the longetivity of people 's lives around the world; it 's now a rarity to hear of people dying of bacterial infections in modern world. Recently we have seen certain types of bacteria develop resistance to…

There are several features about me that describe who I am. For instance; I can be funny, kind, intelligent and headstrong. However, I suffer from acute shyness and tend to panic easily and at times it has caused problems in my personal life. Such as writing essays about myself or having the confidence to stand in front of a room of my peers and present, but my shyness does not define who I am or what I stand for. What defines me are my passions such as animals and biology, my fears and…

transcripts to zygotic transcripts: known as maternal-to-zygotic transition (MZT)) is known to occur during mammalian preimplantation development. A recent study showed that Xenopus oocyte mRNA methylation can regulate translation and cell division during meiosis and early embryo development. Therefore, m6A may possibly play a role in the process of MZT. Finally, the involvement of m6A in onset or progress of human diseases is still elusive. The possibility of this phenomenon in patient derived…

Recombination and mutation are the motivation of evolution. Recombination is critical for repairing DNA lesions and for chromosomal pairing, and exchange during meiosis (Krejci et al. 2012). Recombination does not occur uniformly on the chromosomes of eukaryotes. Meiotic recombination in well studied yeast revealed that non-uniformity of recombination was observed when the frame of reference is an entire chromosome, multigene region and a pair of genes or a small region upstream of a gene…

is thought to follow rules established by Gregor Mendel. One of these rules is the Law of Independent Assortment. It states that genes of the parents will be independently assorted, as a result of crossing over. Crossing over is an event during meiosis when homologous chromosomes line up and exchange genetic information (Bhagat, R, et al.,2004). Resulting offspring follow set phenotypic ratio’s, which are presumed to be the null hypothesis that experiments are tested against (Brooker). In this…

Paramecium’s specific structure of cilia ( small hairs outside of the membrane) allow the organism to respond and move due to detected stimuli from its cilia. In order to reproduce it follows through both sexual, and asexual reproduction, mitosis and meiosis. This organism is a fact which was first encountered, and compared to numerous other organisms, such as humans, who also reproduce, process metabolism, etc. Grouping similar organism together allows scientist to utilize their data…

drift, which is common for populations to very small sizes. Concretely, in the context of sexual reproduction, an individual who reproduces only once, will pass half of its alleles to his descendants. It is during the random genetic mixing, during meiosis that certain alleles will be transmitted and not others. For an individual to transmit all of its alleles, the number of his descendants…

The moss Physcomitrella patens is an attractive model system for plant biology and functional genome analysis.(1-7) It shares many biological features with higher plants (vascular plants) but has the unique advantage of an efficient homologous recombination system for its nuclear DNA.(2,3) This allows precise genetic manipulations and targeted knockouts to study gene function, an approach that due to the very low frequency of targeted recombination events is not routinely possible in any higher…