Inheritance of Autosomal Recessive Disorders

Q.

In sickle cell anaemia, glutamic acid is replaced by valine. Which one of the following triplets codes valine?

1. A A G

2. G G G

3. G U G

4. G A A

Q.

If both parents are carriers for thalassemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?

1. 100%

2. 50%

3. 25%

4. nil

Q. Given below is the pedigree of sickle cell anaemia in a family.


In this, the RBC of both parents will be

1. both normal and sickle shaped
2. cannot be determined
3. normal
4. sickle shaped

Q.

Choose the correct option.

ABO blood groups in humans are controlled by the gene L. It has three alleles– I^A, I^B and i. Since there are three different alleles, six different genotypes are possible. How many phenotypes can occur?

1. One

2. Two

3. Three

4. Four

Q. The first child of a normal pigmented couple is albino. The possibility of a second child being an albino is:

1. 25%
2. 50%
3. 75%
4. 100%

Q.

Mention any two autosomal genetic disorders with their symptoms.

Q. How to solve questions related to Pedigree analysis?

Q. (a) Why are thalassemia and haemophilia categorized as Mendelian disorders? Write the symptoms of these diseases. Explain their pattern of inheritance in humans.
(b) Write the genotypes of the normal parents producing a haemophilic son. [5]

Q. Sickle cell anemia is :

1. An autosomal linked dominant trait
2. Characterized by elongated sickle like RBCs with a nucleus
3. Caused substitute of valine by glutamic acid in the beta globin chain of hemoglobin
4. Caused by a change in a single base pair of DNA

Q. Study the pedigree chart given below and identify the type of inheritance.

1. Incomplete dominance
2. Autosomal recessive
3. Autosomal dominant
4. X-linked dominant

Q. What is the probability of production of dwarf offsprings in a cross between two heterozygous tall pea plants?

1. Zero
2. $50\%$
3. $25\%$
4. $100\%$

Q. Study the pedigree chart given below:


What does it show ?

1. Inheritance of a sex-linked inborn error of metabolism like phenylketonuria
2. Inheritance of a condition like phenylketonuria as an autosomal recessive trait
3. The pedigree chart is wrong as this is not possible
4. Inheritance of a recessive sex-linked disease like haemophilia

Q.

Explain the condition of albinism.

Q. Predict from the following chart

1. character is recessive autosomal
2. character is sex linked recessive
3. character is dominant and carried by X chromosome
4. character is carried by Y chromosome

Q. A couple, both carriers of the gene sickle-cell anemia planning to get married, wants to know the chances of having anemic progeny

1. $100\%$
2. $75\%$
3. $50\%$
4. $25\%$

Q. Assertion: Foetal disorders can be diagnosed by chorionic villi sampling.

Reason: Karyotyping can be done for mitotically dividing cells of chorionic villi.

1. Both assertion and reason are true and reason is the correct
   explanation of assertion
2. Both assertion and reason are true but reason is not the correct explanation of assertion
3. Assertion is true but reason is false
4. Both assertion and reason are false

Q. Which enzyme was targeted during the first clinical gene therapy given in 1990 to a four year- old girl?

1. MAO
2. ADA
3. Tyrosine oxidase
4. Pyruvate dehydrogenase

Q.

What is an example of a monogenic trait?

Q. Which of the following is true for given diagram

1. A is autosomal dominant
2. B is Glutamic acid
3. B is Valine
4. It is caused due to bacteria

Q. A man and a women who both appear normal have a child together who has sickle cell anaemia. Sickle cell anaemia is an autosomal recessive trait. The women becomes pregnant again and is told that she is carrying fraternal twins. What is the probability that both of the couple's twins will develop sickle cell anaemia?

1. $1/16$
2. $1/4$
3. $1/2$
4. $9/16$

Q. Match the genotype with the phenotype with respect to sickle cell anaemia.

1. Affected
2. Normal
3. Carrier

Q.

What is a point mutation example?

Q.

What are Mendelian disorders? Give an example?

Q. What kind of disorder does the pedigree given below represent?


a) Autosomal recessive
b) Autosomal dominant
c) Sex linked
d) Non-inherited
[1 mark]

Q. Thalassemia and sickle cell anaemia are caused due to a problem in globin molecule synthesis.
Select the correct statement.

1. Sickle cell anaemia is due to a quantitative problem of globin molecules
2. Thalassemia is due to less synthesis of globin molecules
3. Both are due to a qualitative defect in globin chain synthesis
4. Both are due to a qualitative defect in globin chain synthesis

Q.

In what state do mutated traits of the autosomal pattern of inheritance occur?

Q. Given below is the pedigree of sickle cell anaemia in a family.


RBC of both parents of the I generation

1. will be sickle shaped
2. will be both normal and sickle shaped
3. will be normal in shape
4. cannot be determined

Q.

Albinism is caused due to overexposure to light.

1. True
2. False

Q. A heterozygous carrier of the hemophilia allele in woman marries with a man who is affected with hemophilia. What will be the expected percentage of hemophilia in their female children?

1. 0%
2. 25%
3. 50%
4. 75%
5. 100%

Q. Haemophilia is a sex-linked recessive disease. Study the pedigree analysis given showing the inheritance of the disease in a family and answer the question that follows.
Write the possible genotype of the individual '2' and '5'.