Down's Syndrome

Q.

If a man having blood group AB marries woman having blood group B, then which of the blood groups is not possible in the progency?

1. B

2. AB

3. A

4. O

Q. The gene for brown eyes is dominant over the gene for blue eyes. Identify the correct statements from the following.

1. Both brown-eyed parents can have blue-eyed child.
2. Both blue-eyed parents will have a blue-eyed child.
3. Blue-eyed person will always have both their alleles different from a brown-eyed person.
4. For a child to be brown-eyed, atleast one parent should be brown-eyed.

Q. Choose the correct pair.

Down syndrome - Sterile female

Turner syndrome - Sterile male

Klinefelter syndrome - Trisomy 21

Q.

Point out the correct difference between primary sexual characteristics and secondary sexual characteristics.

1. Primary sexual characteristics - inborn characteristics i.e. reproductive organs; Secondary sexual characteristics - develop in lifetime like growth of facial hair

2. Primary sexual characteristics - inborn characteristics i.e. growth of facial hair; Secondary sexual characteristics - develop in life time like reproductive organs

3. Primary sexual characteristics - develop in life time i.e. growth of facial hair; Secondary sexual characteristics - Inborn characteristics like reproductive organs

4. Primary sexual characteristics - develop in lifetime i.e. reproductive organs Secondary sexual characteristics - inborn characteristics like growth of facial hair

Q.

What is reparation?

Q.

Why does inbreeding lead to homozygosity?

Q.

The sex determination symbol is XXY in human beings with a syndrome known as:

1. Turners

2. Male Klinefelter

3. Female Klinefelter

4. Downs

Q.

What are the 3 most common physical disabilities?

Q.

What is Cox disease?

Q.

What is the difference between polyploidy and aneuploidy?

Q.

Is turner syndrome caused by male or female?

Q.

Look at the pedigree chart and determine what kind of inheritance pattern it follows.

1. X-linked recessive

2. Autosomal dominant

3. Y-linked inheritance

4. X-linked dominant

Q. Distance between two successive nitrogenous bases or base pairs of DNA is ___.

1. 
2. 
3. 
4. 

Q.

Why is it called missense mutation?

Q.

What is locomotor ataxia disease?

Q.

What Is the source of the extra chromosome 21?

Q.

Monosomy of what causes down syndrome?

Q. ______ is caused by the presence of an extra chromosome number 21.

1. Albinism
2. Down syndrome
3. Klinefelter's syndrome
4. Sickel-cell anaemia

Q.

What is the most common chromosomal disorder in humans?

Q. Pick out the correct statements.
(a) Haemophilia is a sex-linked recessive disease.
(b) Down's syndrome is due to aneuploidy.
(c) Phenylketonuria is an autosomal recessive gene disorder.
(d) Sickle cell anaemia is an X-linked recessive gene disorder.

1. (a) and (d) are correct.
2. (a), (c) and (d) are correct.
3. (b) and (d) are correct.
4. (a), (b) and (c) are correct.

Q. Question 8(ii)
Write notes on -
Secondary sexual characters:

Q.

Is chromatin made of nucleosomes?

Q. A balanced diet is a diet rich in carbohydrates, mild in proteins and low in fats with essential vitamins and minerals. Deficiency of proteins in the diet of children between age group of $1$ to $3$ will not lead to the following symptoms

1. Wasted muscles
2. Oedema
3. Dwarfism
4. Prominent ribs

Q. Albinism, lack of pigmentation in humans, results from an autosomal recessive gene designated 'a'. Parents with normal pigmentation have an albino child. What is the possibility that their next child be albino? What is the possibility that the next child will be an albino girl?

1. 1/4; 1/2
2. 1/2; 1/4
3. 1/4; 1/8
4. 1/8; 1/4

Q.

Are nucleosomes in chromatin?

Q. Number of Barr body present in a female child with down syndrome.

1. $0$
2. $1$
3. $2$
4. All are correct

Q.

Who has kinefelter syndrome?

Q. Down syndrome is the trisomy of chromosome number ___.

1. 21
2. 22
3. 25
4. 29

Q.

Down's Syndrome is caused by trisomy of chromosome number 21. True or False?

1. True

2. False

Q. The structure in chromatin seen as beads-on string when viewed under electron microscope are called _______________.

1. Nucleotides
2. Nucleosomes
3. Histone octamer
4. None of these