Essays on X Chromosome

Gregor Mendel's studies laid the foundation for modern genetics. In a series of elegant experiments, Mendel was able to deduce the most fundamental laws of single-gene and multiple-gene inheritance without having the scientific data on chromosomes, their structure, or meiotic segregation. In this lab, you will learn about and apply examples for 3 different patterns of human inheritance of traits.

Punnett Square is a tool used to theoretically predict genotypes of the progeny from the genotypes of parents as a result of sexual reproduction. Genes from parental gametes are written as rows and columns of the Punnett Square. All ...

Turner’s syndrome is a genetic disorder which mainly affects female growth and development. It is also termed as gonadal dysgenesis which occurs because of the absence of sex chromosome (X). The absence of the X chromosome causes abnormal development in human females. Instead of having a pair of 46 normal XX chromosomes, females with gonadal dysgenesis develop 45,X chromosomes (Castiglia, 1997). This odd combination of chromosomal pairing results in a conflicted sex of the person, where they are neither distinguished as male or female, due to the absence of the second X chromosome that would establish them ...

Hemophilia is an inherited disease that is likely to affect males. It is well-known throughout the history as the most dreadful sickness that prevented normal blood clotting. As a result, diseased people could bleed for hours or even days as they lack a necessary clotting component in their blood. The responsible gene is transmitted in the X chromosome, and this makes males more subjected to the disease. They inherit only one X chromosome, so if it contains mutated gene, it means that a person will surely have the disease. Females have a second X chromosome, and it is usually ...

Turner syndrome is a typical example of a chromosome abnormality caused by the mutation of the chromosomal DNA complex. It is caused by the missing of one sex chromosome in the body. It is presented when the sexual gene orientation of a lady’s chromosome are not complete and lack some genes (Rosenfeld et al. 23). It is caused during the sexual intercourse when a pair of chromosomes fails to separate hence leading to the formation of an embryo with only one X-chromosome. In the embryo formation during copulation, both the parents give out X-chromosomes leading to XX-chromosomes but ...

Description

The Rett syndrome is originally known as cerebroatrophic hyperammonemia. It is a rare genetic disorder which commonly affects women although there are cases where it could be found in male patients. It is considered as a postnatal neurological disorder which affects the grey matter of the brain. Rett syndrome is also considered as a progressive disorder which affects the development of the brain. It is also considered as one of the common cause of mental disorders among women. It occur about 1 in 10,000 births and it typically develops at age 6 to 18 months. The signs or ...

Trisomy

Chromosomes are marvelous things! They carry in their genes the entire genetic code required to build a human being. Comprised of nucleic acid (DNA) and proteins, twenty-three pairs of chromosomes located in the cell nucleus are needed for the normal development of a human embryo. However, sometimes things go wrong. This paper will discuss some of the consequences of faulty chromosome separation during fertilization, resulting in Trisomy. Trisomy is a chromosomal condition which occurs when three chromosomes, instead of the normal two are produced during cell division. This happens due to the failure of human chromosome pairs to separate ...

Abstract

Hemophilia is a genetic condition that is traceable in generations. The disease is usually linked to the excessive bleeding of the patient at a point where the blood vessel is damaged. A lot of research on the disease has been carried out trying to define the origin of the disease and offer extensive support to the solution of the condition. Over time, the disease has attracted extensive attention as the cases of the disease increase. It has not been easy to control the disease since the condition has been overwhelmingly disturbing to the patients as well as the family ...

Turner’s syndrome is a disease that usually affects females. It occurs when one of the X chromosomes (out of the pair of two XX chromosomes) of a female is either missing completely or partially. It can lead to huge numbers of developmental problems and medical complications. Some of the presenting features are short stature, delayed puberty, infertility, defects in the cardiovascular system, inability to grasp or learn new things and problems with social adjustments. The disease can be diagnosed in the gestational phase of the female or during early years of life. It is a rare occurrence that ...

According to Palladino (2006), the Human Genome Project (HGP) was a scientific research project carried out internationally for thirteen years. This project was initiated by the U.S government with the support of other contributors such as public and private researchers with the goal of tracing and mapping nucleotides as found in the human Haploid Reference Genome. In other words the project was driven by the need and interest to collect information about the human genome. In this regard, the project was carried out in order to determine the sequence followed by chemical base pairs which are responsible for the ...

Part 1: Flow Chart

The above figure is a representation of the flow chart showing the chromosomes as they progress through cell cycle starting with G1 to S through to G2 to meiosis and cytokinesis.

G1 phase: The cell undergoes growth at this point

S phase: The cell makes replicates for its chromosomes. Each of the 10 chromosomes then is comprised of 2 sister chromatids.

G2 phase: The duplicated chromosomes are checked by the cell thereby getting them prepared to divide.

Interphase: This represents the period occurring between two cell division All the cells that do not undergo division depart from the cell cycle and go in G0. Part 2 Down syndrome; is a result of extra chromosome 21. They ussualy have 47chromosomes. Klinefelter syndrome; it is as ...

Introduction

Arable soil can be described as soil tilled or ploughed regularly, usually under a crop rotation system. It is also an agricultural soil that is filled by crops sown as well as harvested in a similar agricultural year, at times over one time. Soil can as well be regarded as arable if it is utilized as temporary hayfields for pasture or mowing, kitchen and market gardens, and temporary fallow land. This means that this kind of soil is not sown for one or more seasons of growing, but it is not left to lie idle for over five years. Arable soil ...

1) Proto-Oncogenes and Tumor Suppressor Genes are two types of genes that ordinarily keep the cell cycle functioning as it should. Explain the roles of these two types of genes, and explain what can occur when these types of gene are not working properly. Provide at least two different examples of cancers associated with mutations of these types of genes.

The purpose of the proto-oncogenes under normal circumstances is to make sure that cells proliferate, in other words the oncogenes stimulate cell production. But when a normal, healthy ocogene cell becomes mutated or expresses at higher than normal levels it causes cancer. The first oncogenic virus was discovered in 1916 and called the Rous virus after the person who discovered it, Peyton Rous. Rous viruses represent a family of viruses called the retro viruses. Retro viruses contain a genetic material called ribonucleic acid (RNA).

There is always the possibility that RNA will be transcribed into DNA (deoxyribonucleic acid) by an enzyme of ...

Pedigree Case Analysis

A verified pedigree can help in the determination of the most likely pattern of inheritance of a single-gene disorder in a family. Pedigree analysis also has relevance to the determination of approaches to testing, assessment of recurrence risks, and in some instances, prognosis (Leonard, 2007). The purpose of this paper is multi-pronged. It will analyze the pedigree of a family with the aims of identifying the pattern of inheritance of a trait, additional information required, other relatives at risk, and alternative explanations for the condition.

Additional Information Required

The pedigree illustration provided does not depict the presence of the condition in the preceding two generations on ...

This paper was prepared for course ___________________ for Professor _________________.

THE GAY GENE AND HOMOSEXUALITY Author 2 Even with the plethora of technological advances available to the world, the issue of what exactly determines if an individual becomes a homosexual still remains unresolved. Some people feel homosexuality is a decision based on a person’s environment or is a personal choice, while others contend there has to be some factor in a person’s DNA that makes them harken to homosexuality. No matter what stance a person or organization chooses to select, what is readily apparent is scientific studies of various circumstances, factors and situations have yielded a multitude of results. Therefore, the verdict according ...

This paper was prepared for course ___________________ for Professor _________________.

Even with the plethora of technological advances available to the world, the issue of what exactly determines if an individual becomes a homosexual still remains unresolved. Some people feel homosexuality is a decision based on a person’s environment or is personal choice, while others contend there has to be some factor in a person’s DNA that makes them harken to homosexuality. No matter what stance a person or organization chooses to select, what is readily apparent is scientific studies of various circumstances, factors and situations have yielded a multitude of results. Therefore, the verdict according to a study that was released in February of ...

1.0 Introduction Hemophilia refers to a sex linked recessive, hereditary lifelong bleeding disorder caused by a deficiency or lack of a vital blood-clotting factor. The disorder is therefore associated with excessive and often spontaneous bleeding of mainly internal organs. While hemophilia A is associated with the partial or lack of factor VIII, hemophilia B is a deficiency of factor IX. Without considering the type and severity, there is 1 reported case in every 5000 male births and 1 severe case in every 10,000 male births. Suffice to say that hemophilia A is referred to as the classical hemophilia because it is ...

The cell is the basic unit of all the living organisms. It contains many important structures like chromosomes, which are responsible for the genetic makeup of an organism (Wasserman 111). The cells of an organism undergo a process known as cell division. In this process, a parent cell splits into two or more daughter cells (Wasserman 111). There are two types of cell division namely meiosis and mitosis. It is pertinent to note that, difference is that in mitosis the number of the daughter cells are two whereas, meiosis creates four daughter cells (Wasserman 120). Another thing that differentiates the ...

Describe a test to determine whether the gene is dominant or recessive.

Gregory Mendel is well known scientist who discovered existing patterns in traits inheritance passed from an organism to its offspring. Gregory’s findings led to the establishment of Mendel laws. These laws include; the law of dominance, isolation and Independent assortment. In the case of Curly-eared Cat, mutant gene can either be recessive or dominant. For instance, if a person owns a curled cat and wants to establish if the gene is dominant or recessive, then the following steps can be adopted. First, begin the test by taking the cat to mate with a wild type with a true breeding recessive. A ...

Introduction

Firstly, the rules of competition required that there be no competitor with an undue advantage over the other. This was simply the case when it was rumored that some men competed disguised as women so that they could win in athletic competitions. It was also alleged that intersexed individuals competed as women in order to gain an upper hand. It was for this reason that gender verification was started. The eligibility of a competitor to compete in any sporting event is decided solely on sex. Previously, women paraded nude in front of a team of gynecologists in order to have ...

This essay critically examines the nature of duchenne muscular dystrophy. The condition, affecting 1 out of 3,600 boys, is an inheritable disorder arising due to mutation of the dystrophin gene. To a great extent, duchenne muscular dystrophy can be effectively managed by controlling the symptoms that lead to its development. However, currently, there is no cure for the condition, but with advances in medical technology there is hope for a complete control of the disease through gene therapy.

Clinical Presentation

Duchenne muscular dystrophy is a disease which causes weakening of muscle and leads to eventual death. The condition appears in the ...

Introduction

Genetic evolution refers to change(s) in inheritable traits occurring across succeeding generation of organisms. The change (evolution) is responsible for the diversity at all levels including the molecular level e.g. genetic variations, individual organisms in the same species (intra-species variations) and among species (interspecies variations). It is believed that all organisms emanated from common ancestry about 3.7 billion years ago and then evolved over time to the present biodiversity. Therefore all organisms have some shared traits at the morphological and molecular level with the species sharing a more recent ancestry having more similar traits. The process of evolution involves ...

Genetic diseases are generally caused by abnormality in the individual's genetic makeup or genome. The effect of this abnormality ranges from mild to severe. Those effects depend on the affected genetic components. The changes or abnormalities could be a mutation in a single base to that which could affects the large chromosome. The main forms of occurence are either through inheritance or spontaneous mutations. The basic types of inheritance are; single gene inheritance, multifactoral inheritance, chromosome abnormalities and mitochondrial inheritance. Haemophilia A is a type of chromosomal abnormality associated with a defective X chromosome hence tagged as X-linked disorder.

Haemophilia A

Haemophilia A is a genetic ...

1. Colorbilndness in its extreme meaning, signifying complete lack of person to see any color is very rare; hence the term becomes a misnomer. It is better defined as color vision deficiency which implies that an individual is unable to see the color correctly. These color vision deficiencies vary in their types and degrees. This deficiency is the resultant of faulty coding instructions for the light sensitive pigment present in cones. Cones are one of the constituents of retina of eye and are present in the retina center enabling the individual to see and differentiate between colors. Most common color ...