Target Exam

CUET

Subject

Biology

Chapter

Principles of Inheritance and Variation

Question:

Match List – I with List – II.

List - I

List - II

 (A) Thalassaemia

 (I) Absence of one X chromosome

 (B) Phenylketonuria

 (II) Inborn error of metabolism

 (C) Down's Syndrome 

 (III) Autosomal recessive blood disease

 (D) Turner's Syndrome 

 (IV) Presence of an additional copy of the 21st chromosome 

Choose the correct answer from the options given below:

Options:

(A) - (I), (B) - (II), (C) - (III), (D) - (IV)

(A) - (II), (B) - (III), (C) - (IV), (D) - (I)

(A) - (I), (B) - (II), (C) - (IV), (D) - (III)

(A) - (III), (B) - (II), (C) - (IV), (D) - (I)

Correct Answer:

(A) - (III), (B) - (II), (C) - (IV), (D) - (I)

Explanation:

The correct answer is Option (4) → (A) - (III), (B) - (II), (C) - (IV), (D) - (I)

List - I

List - II

 (A) Thalassaemia

 (III) Autosomal recessive blood disease

 (B) Phenylketonuria

 (II) Inborn error of metabolism

 (C) Down's Syndrome 

 (IV) Presence of an additional copy of the 21st chromosome

 (D) Turner's Syndrome 

 (I) Absence of one X chromosome

A. Thalassemia : This is also an autosome-linked recessive blood disease transmitted from parents to the offspring when both the partners are unaffected carrier for the gene (or heterozygous).The defect could be due to either mutation or deletion which ultimately results in reduced rate of synthesis of one of the globin chains (α and β chains) that make up haemoglobin. This causes the formation of abnormal haemoglobin molecules resulting into anaemia which is characteristic of the disease.

B. Phenylketonuria is an inborn error of metabolism is inherited as an autosomal recessive trait. The affected individual lacks an enzyme that converts the amino acid phenylalanine into tyrosine.

C. Down’s Syndrome : The cause of this genetic disorder is the presence of an additional copy of the chromosome number 21 (trisomy of 21). This disorder was first described by Langdon Down (1866). The affected individual is short statured with small round head, furrowed tongue and partially open mouth. Palm is broad with characteristic palm crease. Physical, psychomotor and mental development is retarded.

D. Turner’s Syndrome : Such a disorder is caused due to the absence of one of the X chromosomes, i.e., 45 with XO, Such females are sterile as ovaries are rudimentary besides other features including lack of other secondary sexual characters.