Explain why women who show no disease symptoms themselves can pass on some heritable diseases to their sons, whereas their daughters seem to be unaffected. Would a disease with this pattern of inheritance be caused by a recessive or a dominant allele?
What will be an ideal response?
Diseases with this pattern of inheritance are caused by defective alleles carried on the X chromosome and are called X-linked diseases. Women have two X chromosomes, one inherited from each parent. A man only has one X chromosome, which he always inherits from his mother. A woman with one X chromosome carrying a recessive disease allele and one X chromosome with a normal allele will show no symptoms of the disease because the normal allele will compensate. However, if she passes on the defective X chromosome to a son, he will show the disease because he has no compensating normal allele. Unless her husband also has the defective allele, which is extremely unlikely because most of these immune defects are very rare, her daughter will also not show the disease even if she inherits a defective X chromosome from her mother. Diseases that show this pattern of inheritance are always recessive. A dominant disease allele carried on an X chromosome will show up as disease equally in women (even if they are heterozygous for the gene) and in men.
You might also like to view...
Stability, as it relates to self-esteem, is best described as
A. a complete absence of mixed messages about oneself from others. B. an integration of the self. C. an unwavering positive self-image. D. a necessary component for the establishment of a sense of love and belonging.
Unscramble each medical term below. A definition for the term is given below each scrambled term.
1. a i h m r t y ___________________ Irregular heartbeat 2. i t p n o p a i l t a_________________ Racing heartbeat 3. a e i m h s c _______________________ Loss of blood supply from occlusion 4. o l b n i l i a t i f r____________________ Abnormal quivering of the heart 5. y r e s o n e i n t p h____________________ High blood pressure 6. r a c y a b d i d_________________________ Abnormally slow heart rate 7. m n u e r s a y_____________________ A weakened and widened artery 8. r o c a y n_________________ Pertaining to the heart 9. l r e a r i t r o c e o s i s____________________ Hardening of an artery 10. m k a c e a e r p______________________ Electrical device to stimulate the heart to beat
The combining form that means red is ________.
Fill in the blank(s) with the appropriate word(s).
The purpose of a treatment plan is to:
a. develop and document a course of action to be taken by or with the client b. analyze appropriate activity skills of a group of clients c. report the client's abilities and limitations to the clinical treatment team d. evaluate the client's performance on a periodic basis