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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.
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संबंधित प्रश्न
Given below is the representation of amino acid composition not the relevant translated portion of β-chain of haemoglobin, related to the shape of human red blood cells
(a) Is this representation indicating a normal human or a sufferer from certain related genetic disease? Give reason in support of your answer.
(b) What difference would be noticed in the phenotype of the normal and the sufferer related to this gene?
(c) Who are likely to suffer more from the defect related to the gene represented the males, the females or both males and females equally? And why?
Mention any two autosomal genetic disorders with their symptoms.
About 8% of the human male population suffers from colour blindness, whereas only about 0.4% of the human female population suffers from this disease. Write an explanation to show how it is possible.
Give a detail account of thalassemia.
Match the Column-I with Column-II and choose the CORRECT answer
| Column-I | Column-II | ||
| P. | Klinefelter syndrome | i. | Mutation in autosomal gene |
| Q. | Thalassaemia | ii. | Mutation sex chromosome linked gene |
| R. | Down syndrome | iii. | Trisomy of autosome |
| S. | Colour blindness | iv. | Trisomy of sex chromosome |
Where are the genes for cytoplasmic male sterility in plants located?
A person with 47 chromosomes due to an additional Y-chromosome suffers from a condition called ______.
Read the following and answer from given below:
Turner's syndrome is an example of monosomy. It is formed by the union of an allosome-free egg and a normal 'X' containing sperm or a normal egg and an allosome-free sperm. The individual has 2n = 45 chromosomes (44 + X0) instead of 46. Such individuals are sterile females who have rudimentary ovaries, underdeveloped breasts, small uterus, short stature, webbed neck, and abnormal intelligence. They may not menstruate or ovulate. This disorder can be treated by giving female sex hormones to women from the age of puberty to make them develop breasts and have menstruation. This makes them feel more normal.
The number of Barr bodies present in a female with Turner's syndrome is ______
The practice of analyzing inheritance patterns in human beings is called ______
Why is the frequency of red-green colour blindness is many times higher in males than that in females?
