GENETICS AND EVOLUTION
INHERITANCE AND VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Sickle-cell anaemia is a genetic disease that is caused by the allele HbS. HbA is the normal allele. A woman does not have the symptoms of the disease but her brother does show symptoms. If her mother and father do not have symptoms, which statement is correct?
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The woman has the genotype HbSHbS.
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The woman’s brother has the genotype HbAHbA.
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The woman’s father and mother both have the genotype HbAHbS.
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The woman’s father and mother both have the genotype HbSHbS.
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Explanation:
Detailed explanation-1: -How Sickle Cell Trait is Inherited. If both parents have SCT, there is a 50% (or 1 in 2) chance that any child of theirs also will have SCT, if the child inherits the sickle cell gene from one of the parents.
Detailed explanation-2: -Sickle cell anaemia is caused by a mutation in the blood pigment haemoglobin. When the faulty haemoglobin is present in a red blood cell, it causes the cell to deform and become sickle-shaped, especially when oxygen levels in the blood become low.
Detailed explanation-3: -When an insect gets stuck, other nearby sticky hairs bend over to trap the insect. Which characteristics of living organisms are demonstrated when the sundew traps insects? A growth and excretion.
There is 1 question to complete.