Science Pg 190

Question 1

What are monogenic disorders?

Answer 1

Diseases occurring due to mutation in a single gene, leading to abnormal metabolism that may result in death at a young age. Approximately 4000 different disorders are classified as monogenic disorders.

Question 2

What are some examples of monogenic disorders?

Answer 2

Examples include Hutchinson’s disease, Tay-Sachs disease, albinism, galactosaemia, phenylketonuria, sickle cell anaemia, cystic fibrosis, hemophilia, and night blindness.

Question 3

What is albinism?

Answer 3

A genetic disorder where the body cannot produce melanin, resulting in pale skin, white hair, and usually pink eyes due to the absence of melanin pigment in the retina and sclera.

Question 4

What causes sickle-cell anaemia?

Answer 4

A minor change in the molecular structure of hemoglobin, where glutamic acid is replaced by valine, causing red blood cells to become sickle-shaped and reducing their oxygen-carrying capacity.

Question 5

What are the types of individuals affected by sickle-cell anaemia?

Answer 5

1. Sickle-cell anaemia carrier (AS)
2. Sufferer from sickle-cell anaemia (SS)

Question 6

What are the symptoms of sickle-cell anaemia?

Answer 6

Symptoms include swelling of hands and legs, pain in joints, severe body aches, frequent colds and cough, constant low-grade fever, exhaustion, and pale face.

Question 7

How is sickle-cell anaemia inherited?

Answer 7

It occurs due to changes in genes during conception. If both parents are affected or carriers, their offspring are likely to suffer from the disease.