8)Describe the individuals with the following
chromosomal abnormalities:
a)Trisomy at
chromosome 21
b) XXY
c) XO
chromosomal abnormalities:
a)Trisomy at
chromosome 21
b) XXY
c) XO
Dear student, Ans 1. Down’s Syndrome causes due to the presence of an additional copy of chromosome 21 (Trisomy of 21). The trisomy means occurrence of three copies of the chromosome number 21, which occurs by non disjunction of chromosomes during gametic meiosis. An individual with Down's syndrome is characterised by webbed neck, short stature, mongoloid face, protruding tongue, bulging eyes, mental retardation and are short lived.
Ans 2. Klinefelter syndrome, also known as the XXY condition, is a term used to describe males who have an extra X chromosome in most of their cells. Instead of having the usual XY chromosome pattern that most males have, these men have an XXY pattern. Even though all men with Klinefelter syndrome have the extra X chromosome, not every XXY male has all of those symptoms. It results in feminized male which means male with female characters. The frequency of occurrence of this syndrome is 1 in 500.
Symptoms: Inattentiveness, Breast enlargement in men, Delayed puberty, Flaccid muscles, Infertility along with reduced sex drive, or small penis, low-set ears, osteoporosis
Ans 3. Turner's syndrome: It is a genetic disorder that is caused due to the absence of one X chromosome, i.e., individual has 45 chromosomes with XO. The affected females are sterile with rudimentary ovaries. Secondary sexual characters are also absent.
Regards.
Ans 1. Down’s Syndrome causes due to the presence of an additional copy of chromosome 21 (Trisomy of 21). The trisomy means occurrence of three copies of the chromosome number 21, which occurs by non disjunction of chromosomes during gametic meiosis. An individual with Down's syndrome is characterised by webbed neck, short stature, mongoloid face, protruding tongue, bulging eyes, mental retardation and are short lived.
Ans 2. Klinefelter syndrome, also known as the XXY condition, is a term used to describe males who have an extra X chromosome in most of their cells. Instead of having the usual XY chromosome pattern that most males have, these men have an XXY pattern. Even though all men with Klinefelter syndrome have the extra X chromosome, not every XXY male has all of those symptoms. It results in feminized male which means male with female characters. The frequency of occurrence of this syndrome is 1 in 500.
Symptoms: Inattentiveness, Breast enlargement in men, Delayed puberty, Flaccid muscles, Infertility along with reduced sex drive, or small penis, low-set ears, osteoporosis
Ans 3. Turner's syndrome: It is a genetic disorder that is caused due to the absence of one X chromosome, i.e., individual has 45 chromosomes with XO. The affected females are sterile with rudimentary ovaries. Secondary sexual characters are also absent.
Regards.
