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Principles of Inheritance and Variation

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Biology

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Biology

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CBSE Gujarat Board Haryana Board

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Class 10 Class 12

Both sickle cell anaemia and Huntington's chorea are

  • bacteria-related diseases

  • congenital disorders

  • pollutant-induced disorders

  • virus-related diseases


B.

congenital disorders

Both sickle cell anaemia and Huntington's chorea are congenital genetic disorders. Sickle cell anaemia was first opened by James Herrick (1904). In this disease the patient's haemoglobin level reduced to half of the normal and the RBCs become sickle shaped. A single mutation in a gene can cause sickle cell anaemia.
Huntington's chorea is caused by autosomal mutation which is dominant. The gene is present on chromosome number 4.

Both sickle cell anaemia and Huntington's chorea are congenital genetic disorders. Sickle cell anaemia was first opened by James Herrick (1904). In this disease the patient's haemoglobin level reduced to half of the normal and the RBCs become sickle shaped. A single mutation in a gene can cause sickle cell anaemia.
Huntington's chorea is caused by autosomal mutation which is dominant. The gene is present on chromosome number 4.

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Mention the phenomenon of pleiotropy by giving an example.

Pleiotropy. When one gene controls more than one phenotypic character it is termed as pleiotropy.

Example : Sickle cell anaemia.

825 Views

Name one trait that does not blend.

Sex trait .
1181 Views

Give one example of genetic trait for each of the following in humans : (i) Lethality (ii) Multiple allelism.

(i) Lethality : Sickle cell anaemia.

(ii) Multiple allelism : ABO blood groups.

815 Views

Name the plant that shows incomplete dominance in respect of the colour of its flower.

The plany which shoes incomplete dominace in respect of the colour of its flower is -

Snapdragron ( Antirrhinum majus)

Or 

Mirabilis jalapa (Four-O- Clock plant ).
1012 Views

What for symbols AA and Aa stand ?

AA : Homozygous dominant, Aa : Heterozygous dominant.
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