Chromosomal crossover

Although Down syndrome is used as a general term, several forms of this syndrome exist. Trisomy 21 is considered one of the most common genetic chromosomal disorders in the world. This year alone, approximately 6000 children within the United States will be born with this genetic disorder. Trisomy 21, also known as Down syndrome is defined as a set of physical and mental traits caused by an abnormal gene mutation that happens before birth. This genetic disorder varies in severity, causes…

commonly occurring chromosomal condition? There is a lot more to Downs’ syndrome than people think. There are many fascinating facts about this condition that are not in the common knowledge! Downs’ syndrome is a genetic disorder which is caused by an error in cell division that results in the presence of an extra copy of chromosome 21. Most of the time the error occurs at random during the formation of an egg or sperm. Research shows that there are three types of chromosomal changes that can…

and he called them mongoloids. Down syndrome, also known as Trisomy 21, is a condition where a person has been born with an extra copy of chromosome 21. Dr. Jerome Lejeune; a French physician discovered that being "mongoloid" was a result from a chromosomal abnormality, which meant the…

Every year an estimated 7.9 million babies are born with serious birth defects. The main genetic causes of birth defects fall into three general categories chromosome abnormalities, single gene defects, and multifactorial influences. Down syndrome is one of them, which is the most common chromosome disorder genetic lead to moderate or severe mental retardation. Down syndrome affecting one in eight hundred infants, the risk of having a child with this condition increases with maternal age rising…

Cri Du Chat Syndrome Section 1 The genetic disorder Cri Du Chat stems from the deletion of a portion the p arm of chromosome 5 in the affected person. This deletion is seemingly spontaneous in most affected individuals. “Approximately 90% of cases results from a sporadic, or randomly-occurring, de novo deletion” (6. pg. 606). This deletion may include a fraction to the entire loss of the p arm of the fifth chromosome as a whole. Taking into consideration the very spontaneous nature of…

Cri du chat syndrome, also referred to as cat cry syndrome and 5p deletion, is a chromosomal disorder resulting from the deletion of the short arm, known as the p arm on chromosome 5 (1). This disease was first described in 1963 by a French geneticist, Jerome Lejeune as a hereditary congenital syndrome (1). Today, it is known as one of most frequent autosomal deletion syndromes that results from loss of the distal portion of chromosome 5 affecting the telomerase reverse transcriptase (TERT)…

Introduction Children, adolescents and adults suffer from a mental and physical disorder known as Down syndrome. This disorder is due to an extra chromosome in their genes which is the leading cause. However, a specific chromosome can also be damaged during cell replication, which can also increase their risk of getting Down syndrome and other disorders later on in their life that could eventually lead to death if not treated at the right time. Also, if a mother gives birth at a higher age, it…

Have you ever wondered about Down Syndrome and what exactly causes it, or even the health problems that these children and adults face? Down Syndrome, often known as DS, is a genetic condition which is caused by an extra chromosome. Down Syndrome is also the most common genetic disorder. There is no way of preventing Down Syndrome, although genetic counseling is available to figure the odds of having a baby with Downs. Over the course of many years, more tests and screenings have become…

Barbra McClintock was born June 16, 1902, in Hartford, Connecticut (Editors). The third of four children born to physician Thomas McClintock and wife Sarah, McClintock was christened Eleanor, though her parents soon began to call her Barbra believing the nickname better suited her pragmatic demeanor (“Barbra McClintock”). Barbra demonstrated an interest in science from a young age, perhaps influenced by her father’s profession (Editors). At the age of seventeen, she graduated from high school…

BARBARA MCCLINTOCK BY FRANCESCA MAKUCH Barbara McClintock was born June 16, 1902. Her death was in 1992. She was born in Hartford, Connecticut. She was the third child out of four. McClintock went to college September 1919 at Cornell University in Ithaca, New York. She went two years without looking at a genetic course. Then during her third year, she took a genetic course. Immediately she loved the course. That year her professor asked if next year she could take a more advanced class, she did…