Advertisements
Advertisements
प्रश्न
Why are thalassemia and haemophilia categorized as Mendelian disorders? Write the symptoms of these diseases. Explain their pattern of inheritance in humans.
Advertisements
उत्तर
Thalassaemia and haemophilia are categorised as Mendelian disorders because these are determined by alternation or mutation in a single gene.
Symptoms of thalassaemia: The main symptoms of thalassaemia are anaemia, jaundice, hepatosplenomegaly, cardiac enlargement and skeletal deformities.
Symptoms of haemophilia: Haemophilia is also called bleeder’s disease in which a single cut leads to non-stop bleeding. It prevents clotting of blood. A seriously affected person may bleed to death after even a minor skin cut.
Inheritance pattern of haemophilia:
This is a sex-linked recessive disease which shows its transmission from an unaffected carrier female to some of the male progeny. It shows criss-cross inheritance. The heterozygous female (carrier) for haemophilia may transmit the disease to sons. The possibility of a female becoming a haemophilic is extremely rare because the mother of such a female would have to be at least a carrier and the father should be haemophilic.
Inheritance pattern of thalassaemia:
Thalassaemia is an autosomal, recessively inherited blood disorder transmitted to the offspring when both parents are heterozygous. The defect arises because of either mutation or deletion which results in the reduced rate of synthesis of one of the globin chains of haemoglobin.
संबंधित प्रश्न
If only one 'X' chromosome is found in a female person, which of the following symptoms she will show?
- epicanthal skin fold
- webbing of neck
- small testis and absence of spermatogenesis
- presence of simian crease on the palm
During a medical investigation, an infant was found to possess an extra chromosome 21. Describe the symptoms the child is likely to develop later in the life.
Give the importance of heterocyst in cyanobateria.
Which of the following characteristics are observed in a person suffering from Turner syndrome?
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.
Thalassemia and sickle cell anemia are caused due to a problem in globin molecule synthesis. Select the correct statement.
If a colour-blind man marries a woman who is homozygous for normal colour vision, the probability of their son being colour-blind is ______.
Females with Turner’s syndrome have ______.
Rajesh and Mahesh have defective haemoglobin due to genetic disorders. Rajesh has too few globin molecules while Mahesh has incorrectly functioning globin molecules. Identify the disorder they are suffering from.
| Rajesh | Mahesh | |
| A. | Sickle cell anaemia - an autosome linked recessive trait | Thalassemia - an autosome linked dominant trait |
| B. | Thalassemia - an autosome linked recessive blood disorder | Sickle cell anaemia - an autosome linked recessive trait |
| C. | Sickle cell anemia - an autosome linked recessive trait | Thalassemia - an autosome linked recessive blood disorder |
| D. | Thalassemia - an autosome linked recessive blood disorder | Sickle cell anaemia - an autosome linked dominant trait |
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.
Turner's syndrome is an example of ______
