Gametogenesis (genetic/congenital disorders):
1. Give an explanation for increased incidence of non-disjunction with age in females.
2. Describe the correlation between parental ages and genetic/congenital disorders.
3. Describe teratocarcinoma including location, cause and form. 15
4. How embryonic stem cell lines area related to teratocarcinoma and how are they used in research? What would be their potential clinical use?
5. Identify karyotypes and know the common names, life expectancy, prevalence and major systems of the following abnormalities of chromosome number Trisomy 21; Trisomy 18 &Trisomy 13;
6. Explain why sex chromosome non-disjunctions are more common than autosomes. List the karyotype for Turners and Klinefelter’s Syndrome.
Sample solution
Dante Alighieri played a critical role in the literature world through his poem Divine Comedy that was written in the 14th century. The poem contains Inferno, Purgatorio, and Paradiso. The Inferno is a description of the nine circles of torment that are found on the earth. It depicts the realms of the people that have gone against the spiritual values and who, instead, have chosen bestial appetite, violence, or fraud and malice. The nine circles of hell are limbo, lust, gluttony, greed and wrath. Others are heresy, violence, fraud, and treachery. The purpose of this paper is to examine the Dante’s Inferno in the perspective of its portrayal of God’s image and the justification of hell.
In this epic poem, God is portrayed as a super being guilty of multiple weaknesses including being egotistic, unjust, and hypocritical. Dante, in this poem, depicts God as being more human than divine by challenging God’s omnipotence. Additionally, the manner in which Dante describes Hell is in full contradiction to the morals of God as written in the Bible. When god arranges Hell to flatter Himself, He commits egotism, a sin that is common among human beings (Cheney, 2016). The weakness is depicted in Limbo and on the Gate of Hell where, for instance, God sends those who do not worship Him to Hell. This implies that failure to worship Him is a sin.
God is also depicted as lacking justice in His actions thus removing the godly image. The injustice is portrayed by the manner in which the sodomites and opportunists are treated. The opportunists are subjected to banner chasing in their lives after death followed by being stung by insects and maggots. They are known to having done neither good nor bad during their lifetimes and, therefore, justice could have demanded that they be granted a neutral punishment having lived a neutral life. The sodomites are also punished unfairly by God when Brunetto Lattini is condemned to hell despite being a good leader (Babor, T. F., McGovern, T., & Robaina, K. (2017). While he commited sodomy, God chooses to ignore all the other good deeds that Brunetto did.
Finally, God is also portrayed as being hypocritical in His actions, a sin that further diminishes His godliness and makes Him more human. A case in point is when God condemns the sin of egotism and goes ahead to commit it repeatedly. Proverbs 29:23 states that “arrogance will bring your downfall, but if you are humble, you will be respected.” When Slattery condemns Dante’s human state as being weak, doubtful, and limited, he is proving God’s hypocrisy because He is also human (Verdicchio, 2015). The actions of God in Hell as portrayed by Dante are inconsistent with the Biblical literature. Both Dante and God are prone to making mistakes, something common among human beings thus making God more human.
To wrap it up, Dante portrays God is more human since He commits the same sins that humans commit: egotism, hypocrisy, and injustice. Hell is justified as being a destination for victims of the mistakes committed by God. The Hell is presented as being a totally different place as compared to what is written about it in the Bible. As a result, reading through the text gives an image of God who is prone to the very mistakes common to humans thus ripping Him off His lofty status of divine and, instead, making Him a mere human. Whether or not Dante did it intentionally is subject to debate but one thing is clear in the poem: the misconstrued notion of God is revealed to future generations.
References
Babor, T. F., McGovern, T., & Robaina, K. (2017). Dante’s inferno: Seven deadly sins in scientific publishing and how to avoid them. Addiction Science: A Guide for the Perplexed, 267.
Cheney, L. D. G. (2016). Illustrations for Dante’s Inferno: A Comparative Study of Sandro Botticelli, Giovanni Stradano, and Federico Zuccaro. Cultural and Religious Studies, 4(8), 487.
Verdicchio, M. (2015). Irony and Desire in Dante’s” Inferno” 27. Italica, 285-297.
Sample Answer
Sample Answer
Explanation for increased incidence of non-disjunction with age in females:
The increased incidence of non-disjunction with age in females can be attributed to the process of oogenesis. During fetal development, females have a finite number of oocytes that are arrested in prophase I until puberty. As women age, the oocytes continue to age along with them. Over time, the chromosomes in these oocytes become more susceptible to errors during meiosis, particularly during the first meiotic division (meiosis I). Non-disjunction occurs when homologous chromosomes fail to separate properly, leading to an incorrect distribution of chromosomes in the resulting gametes. This can result in the formation of eggs with an abnormal number of chromosomes, such as trisomy or monosomy, which can lead to genetic disorders.
Correlation between parental ages and genetic/congenital disorders:
Parental ages have been correlated with an increased risk of genetic and congenital disorders. Advanced maternal age, usually defined as 35 years or older, is associated with an elevated risk of chromosomal abnormalities in offspring, such as Down syndrome (Trisomy 21). This is mainly due to the increased incidence of non-disjunction in older women’s oocytes. Paternal age also plays a role, although the effect is generally less pronounced compared to maternal age. Advanced paternal age has been associated with an increased risk of certain genetic disorders, including autosomal dominant conditions and de novo mutations.
Teratocarcinoma:
Teratocarcinoma is a type of germ cell tumor that typically arises from pluripotent cells in the gonads (ovaries or testes). These tumors are composed of a mixture of tissues derived from different germ layers and can contain elements resembling embryonic tissue. Teratocarcinomas can occur in both males and females but are most commonly found in the ovaries or testes. The exact cause of teratocarcinoma is not well understood, but it is believed to involve genetic and epigenetic alterations in germ cells. Teratocarcinomas can be malignant and have the potential to metastasize to other parts of the body.
Embryonic stem cell lines and their relationship to teratocarcinoma:
Embryonic stem cell lines are derived from blastocysts and share some similarities with teratocarcinoma cells. Both cell types are pluripotent, meaning they have the ability to differentiate into various cell types. Teratocarcinomas are tumors that contain pluripotent cells, including embryonic stem cells. However, it is important to note that not all pluripotent stem cells are tumorigenic or associated with teratocarcinoma.
In research, embryonic stem cell lines derived from blastocysts have been used extensively to study developmental processes, disease modeling, and potential therapeutic applications. They provide a valuable tool for understanding cell differentiation and regenerative medicine. However, their use can be controversial due to ethical concerns related to the destruction of human embryos during the derivation process.
Karyotypes and characteristics of common abnormalities of chromosome number:
Trisomy 21 (Down syndrome):
Karyotype: 47, XY or 47, XX, +21
Life expectancy: Varies, but typically reduced compared to individuals without Down syndrome.
Prevalence: Approximately 1 in 700-1,000 live births.
Major Systems Affected: Intellectual disability, characteristic facial features, congenital heart defects, gastrointestinal abnormalities, increased risk of leukemia, and early-onset Alzheimer’s disease.
Trisomy 18 (Edwards syndrome):
Karyotype: 47, XY or 47, XX, +18
Life expectancy: Generally reduced, with many affected individuals not surviving beyond infancy.
Prevalence: Approximately 1 in 5,000 live births.
Major Systems Affected: Severe intellectual disability, characteristic facial features, congenital heart defects, clenched hands with overlapping fingers, kidney abnormalities, and growth retardation.
Trisomy 13 (Patau syndrome):
Karyotype: 47, XY or 47, XX, +13
Life expectancy: Generally reduced, with many affected individuals not surviving beyond infancy.
Prevalence: Approximately 1 in 10,000-16,000 live births.
Major Systems Affected: Severe intellectual disability, cleft lip/palate, polydactyly (extra fingers/toes), congenital heart defects, kidney abnormalities, and eye abnormalities.
Explanation for the higher frequency of sex chromosome non-disjunctions than autosomes:
Sex chromosome non-disjunctions occur more frequently than autosomal non-disjunctions due to unique features of sex chromosome pairing and segregation during meiosis. During male meiosis (spermatogenesis), sex chromosomes (X and Y) pair and segregate differently than autosomes. The X and Y chromosomes have limited areas of homology known as pseudoautosomal regions (PARs) that enable pairing during meiosis I. However, a portion of the X and Y chromosomes does not undergo recombination, leading to a higher likelihood of errors during segregation.
Additionally, sex chromosome non-disjunction events often result in viable offspring due to the presence of redundant sex chromosomes (XX or XY). In contrast, autosomal non-disjunction events usually lead to embryos with abnormal chromosome numbers (e.g., trisomy or monosomy), which are less likely to be viable.
Karyotypes:
Turner Syndrome:Karyotype: 45,X (monosomy X)
Klinefelter Syndrome:Karyotype: 47, XXY (extra X chromosome)
