THE NATURE and SCOPE OF PSYCHOLOGY LESSON AIM Define psychology and explain basic theoretic approaches Despite their interest in the subject, students of psychology often find it difficult to answer this basic question in a clear, concise an d specific manner.
X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males (who are necessarily hemizygous for the gene mutation because they have one X and one Y chromosome) and in females who are homozygous for the gene mutation, see zygosity.
The most common X-linked recessive disorders are: 1  Red-green color blindness, a very common trait in humans and frequently used to explain X-linked disorders. 2  Hemophilia A, a blood clotting disorder caused by a mutation of the Factor VIII gene and leading to a deficiency of Factor VIII.