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प्रश्न
Write a note on Down’s syndrome.
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उत्तर
Down syndrome:
- Individuals suffering from Down syndrome will have 47 chromosomes instead of the normal number 46.
- 21st Trisomy occurs due to non-disjunction or failure of separation of chromosomes (autosomes) during gamete formation.
- Following are the symptoms of Down syndrome:
- Mild or moderate mental retardation and poor skeletal development.
- Distinct facial features like small head, ears, and mouth.
- The face is typically flat and rounded with a flat nose, open mouth, and protruding tongue.
- Eyes slant up and out with internal epicanthal folds.
- Flat hands and stubby fingers, the palm is broad with a single palmer crease.
APPEARS IN
संबंधित प्रश्न
What is ‘syndrome’?
Attempt any TWO of the following:
‘The gene for sickle cell anaemia in homozygous condition is lethal and produces sickle cell trait in heterozygous carrier’. Explain.
Webbed neck is characteristic of ______ syndrome.
Give a detail account of thalassemia.
Match the Column I and Column II and select the correct option.
| List-I | List-II | ||
| i. | Holandric genes | a. | Pleiotropy |
| ii. | Multiple effects of a single gene | b. | Hypertrichosis |
| iii. | Skin colour in man | c. | Multiple Alleles |
| iv. | ABO Blood types | d. | Polygenic inheritance |
The correct answer is
Which of the following characteristics are observed in a person suffering from Turner syndrome?
Identify the disease caused by an autosomal primary non-disjunction.
In sickle-cell anaemia, shape of RBCs under oxygen tension becomes ______.
Mental retardation in man associated with sex chromosomal abnormality is usually due to ______.
Failure of segregation of chromatids during cell division results in the gain or loss of chromosomes, this is called as ______.
