Test: Physiological Variations - JAMB MCQ

Physiological variation refers to differences or variations observed in various physiological traits among individuals. Height, eye color, and blood type are all examples of such variations observed in the human population.

The ability to roll the tongue is an example of discontinuous variation because it is controlled by a single gene and is observed as either present or absent. Individuals can either roll their tongue (dominant trait) or cannot roll their tongue (recessive trait), resulting in distinct categories.

The ability to taste PTC is determined by genetic factors. Some individuals have a specific gene that allows them to taste PTC, while others lack this gene and cannot taste it. This genetic difference leads to the observed variation in PTC taste perception among individuals.

Blood type AB is considered the universal recipient in blood transfusion because individuals with blood type AB can receive blood from any blood type without causing an adverse immune reaction. This is because blood type AB individuals have both A and B antigens on their red blood cells, making them compatible with all blood types.

If the parents have blood groups A and B, it is impossible for their child to have blood group O. This is because blood group O is recessive and can only be inherited if both parents pass on an O allele. Since neither parent has an O allele, the child cannot have blood group O.

The ABO blood group system is based on the presence or absence of specific antigens on the surface of red blood cells. Blood types A, B, AB, and O represent different combinations of these antigens. The presence or absence of antigens determines an individual's blood type.

Blood type O individuals are considered universal donors because their red blood cells do not have A or B antigens. As a result, individuals with blood type O can donate blood to individuals with any other blood type (A, B, AB, or O).

Discontinuous variation, which involves distinct categories or traits, can be useful in crime detection. Unique genetic markers, such as those found in DNA fingerprinting, can be used to identify individuals based on specific genetic patterns, providing valuable evidence in criminal investigations.

The ability to taste PTC is an example of discontinuous variation because it is controlled by a single gene and is observed as either present or absent. Individuals can either taste PTC (dominant trait) or cannot taste PTC (recessive trait), resulting in distinct categories.

The ABO blood group system involves three alleles: A, B, and O. An individual inherits two alleles—one from each parent—to determine their blood type. The possible combinations of these three alleles give rise to the four blood types: A, B, AB, and O.