Carriers vs Affected Individuals

Q.

In humans, the ability to roll the tongue is a dominant trait. The inability to roll the tongue is a recessive trait. If two individuals homozygous recessive for this trait have a child, what is the chance that the child will be able to roll his tongue?

1. 0%

2. 25%

3. 50%

4. 100%

Q.

Choose the correct option-

A human male produces sperms with the genotypes AB, Ab, aB, and ab pertaining to two diallelic characters in equal proportions. What is the corresponding genotype of this person?

1. AABb

2. AaBB

3. AaBb

4. AABB

Q.

Colour blindness and sickle cell anaemia are examples of Mendelian disorders. True or false?

1. True

2. False

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

Q. A couple, both carriers of the gene responsible for sickle-cell anemia, is planning to get married and wants to know the chances of their children inheriting the disease.

1. $100\%$

2. $25\%$

3. $75\%$

4. $50\%$

Q.

In an autosomal recessive disorder, two copies of an abnormal gene must be present in order for the symptoms of the disease to develop.

1. True

2. False

Q.

In diseases that show X-linked inheritance, the females are usually the ______.

1. Promoters

2. Carriers

3. Operators

4. None of the above

Q.

Two copies of an abnormal gene must be present in order for the disease or trait to develop in

1. Autosomal recessive disorder

2. Autosomal dominant disorder

3. Sex-linked disorders

4. Y-linked disorders

Q. Queen Victoria of England was a

1. Carrier for colour blindness
2. Carrier for haemophilia
3. Deaf
4. AIDS patient

Q. If a colourblind man is married to a normal woman, then from the point of view of disease, their offsprings will be

1. All daughters will be colourblind.
2. All sons will be colourblind.
3. All sons and daughters will be normal.
4. All sons and daughters will be colour blind.

Q. In humans the gene for red and green colour blindness is located on the sex chromosome. If a male is colour blind and is a child of normal visioned parents, then who among the following in his family is likely to be colour blind?

1. Maternal grandfather
2. Maternal grandmother
3. Paternal grandfather
4. Paternal grandmother

Q. A woman with normal vision but with colourblind father marries a colourblind man. The fourth child of the couple is a boy. This boy

1. May or may not be colourblind
2. Must be colourblind
3. Must have normal vision
4. Will be partially colourblind due to being heterozygous

Q. Recessive mutation is not expressed in ________________.

1. Homozygous male
2. Heterozygous male
3. Heterozygous female
4. Homozygous female

Q.

X-linked disorders are called as royal diseases since they were prevalent in the Royal Family of England.

1. True

2. False