PATHOLOGY MCQ
GENETICS AND DISEASE
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Cystic Fibrosis
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Sickle-cell Disease
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Down Syndrome
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Hemophilia
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Detailed explanation-1: -The altered form of hemoglobin that causes sickle-cell anemia is inherited as a codominant trait. Specifically, heterozygous (Ss) individuals express both normal and sickle hemoglobin, so they have a mixture of normal and sickle red blood cells.
Detailed explanation-2: -The sickle cell anemia trait is found on a recessive allele of the hemoglobin gene. This means that you must have two copies of the recessive allele-one from your mother and one from your father-to have the condition.
Detailed explanation-3: -Sickle cell disease is caused by a variant of the beta-globin gene called sickle hemoglobin (Hb S). Inherited autosomal recessively, either two copies of Hb S or one copy of Hb S plus another beta-globin variant (such as Hb C) are required for disease expression.
Detailed explanation-4: -Sickle Cell Anaemia is called a recessive condition because you must have two copies of the sickle haemoglobin gene to have the disorder. Sickle haemoglobin is often shortened to S or HbS.
Detailed explanation-5: -Sickle cell anemia is a disease where red blood cells become thin and elongated. If a person has one copy of the sickle cell allele, half of their red blood cells will be misshapen. In this way, the allele is codominant, since both normal and sickled shapes are seen in the blood.