Explain X-linked inheritance and how it affects both males and females
What will be an ideal response?
Answer: Males and females have an equal chance of inheriting recessive disorders carried on the autosomes, such as PKU and sickle cell anemia. But when a harmful allele is carried on the X chromosome, X-linked inheritance applies. Males are more likely to be affected because their sex chromosomes do not match. In females, any recessive allele on one X chromosome has a good chance of being suppressed by a dominant allele on the other X. But the Y chromosome is only about one-third as long and therefore lacks many corresponding genes to override those on the X. A well-known example is hemophilia, a disorder in which the blood fails to clot normally. There is a greater likelihood of inheritance by male children whose mothers carry the abnormal allele.
You might also like to view...
When the protein called corticotropin-releasing hormone (CRH) reaches a high enough concentration, the mother's uterus begins periodic contractions.
Answer the following statement true (T) or false (F)
A diagnosis of bipolar II disorder indicates that the person has experienced __________.
A. an episode of mania B. an episode of mania or major depression C. an episode of hypomania and an episode of major depression D. an episode of mania and an episode of major depression
Michael and Matthew are identical twins. The boys share ______ % of their genes. Pia and Lacy are fraternal twins. The girls share about ______ % of their genes.
A. 50; 25 B. 100, 100 C. 75, 25 D. 100; 50
Chemical substances in the nervous system that are similar in structure and in action to opiates—such as heroin and morphine—are ________
a. hormones. b. endorphins. c. androgens. d. neurotransmitters.