Describe Mendelian Disorder
Describe Mendelian Disorder
Mendelian disorders are mainly determined by alteration or mutation in the single gene. These disorders are transmitted to the offspring on the same lines as we have studied in the principle of inheritance.
The pattern of inheritance of such Mendelian disorders can be traced in a family by the pedigree analysis.
Most common and prevalent Mendelian disorders are Haemophilia, Cystic fibrosis, Sickle-cell anaemia, Colour blindness, Phenylketonuria, Thalesemia, etc. It is important to mention here that such Mendelian disorders may be dominant or recessive.
By pedigree analysis one can easily understand whether the trait in question is dominant or recessive. Similarly, the trait may also be linked to the sex chromosome as in case of haemophilia.
It is evident that this $X-$linked recessive trait shows transmission from carrier female to male progeny. A representative pedigree is shown in Figure for dominant and recessive traits,
Similar Questions
:Match the columns :
Column $I$
Column $II$
$(a)$ Sickle cell anaemia
$(x)$ Homogentisic acid
$(b)$ Alkaptonuria
$(y)$ Melanin pigmentsare absent
$(c)$ Albinism
$(z)$ More amount of phenyl alanine
$(d)$ Phenyl Ketonuria
$(w)$ Defective haemoglobin
:Match the columns :
| Column $I$ |
Column $II$ |
| $(a)$ Sickle cell anaemia | $(x)$ Homogentisic acid |
| $(b)$ Alkaptonuria | $(y)$ Melanin pigmentsare absent |
| $(c)$ Albinism | $(z)$ More amount of phenyl alanine |
| $(d)$ Phenyl Ketonuria | $(w)$ Defective haemoglobin |
If a colour blind lady marries a normal man, their children will be
If a colour blind lady marries a normal man, their children will be
- [AIPMT 1999]
Which of the following abnormalities is due to autosomal dominant mutation?
Which of the following abnormalities is due to autosomal dominant mutation?
If a boy's father has haemophilia and his mother has one gene for haemophilia; what is the chance that the boy will inherit the disease
If a boy's father has haemophilia and his mother has one gene for haemophilia; what is the chance that the boy will inherit the disease
- [AIIMS 1999]
In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased? (In $\%$)
In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased? (In $\%$)
- [NEET 2021]