Advertisements
Advertisements
Questions
Identify chromosomal disorder caused due to non-disjunction of the 21st number of chromosomes and enlist its symptoms.
Identify chromosomal disorder caused due to non-disjunction of 21% chromosome and enlist its characteristics.
Solution
Down syndrome is usually caused by an error in cell division called non-disjunction. Non-disjunction results in an embryo with three copies of chromosome 21 instead of the usual two.
Common Symptoms (Characteristics) of Down syndrome are:
- Mild or moderate mental retardation and poor skeletal development.
- Distinct facial features like small head, ears and mouth.
- Eyes slant up and out with internal epicanthal folds.
APPEARS IN
RELATED QUESTIONS
Which of the following traits is never observed in a human female?
Give an account of one Mendelian and one chromosomal disorder you have studied.
A male rabbit of genotype 'AABBDDEE' is crossed with a female rabbit of genotype 'aabbddee' to produce F1 hybrid offspring. How many genetically different gametes can be produced by this F1 hybrid?
Identify the characteristics that are observed in an individual suffering from Klinefelter syndrome.
i. Gynaecomastia, under developed testis and no spermatogenesis.
ii. Voice pitch is harsh.
iii. They are tall with long arms.
Choose the correct option which appropriately classifies the following disorders into Mendelian and chromosomal disorders:
Colour blindness, Down syndrome, Sickle cell anaemia, Turner syndrome, Thalassemia, Haemophilia, Phenylketonuria, Klinefelter syndrome.
In sickle cell anaemia glutamic acid is replaced by valine. Which one of the following triplets codes for valine?
Extra chromosome ‘X’ is present in which one of the following cases?
Mental retardation in man associated with sex chromosomal abnormality is usually due to ______.
Females with Turner’s syndrome have ______.
The technique exployed in human genetic counselling is:
