It is inherited in an autosomal recessive manner and is caused by a mutation in the HBB gene. The mutation that causes hemoglobin E disease primarily occurs in Southeast Asian populations, and rarely in Chinese populations. Most people with HbE disease do not need any treatment.
CHAPTER 27 Homework Review ï· The ability of sperm cells to move along the ductus deferens is due to ________. peristaltic contractions ï· Prostate cancer is _______.sometimes a slow-growing cancer that may never represent a threat to the patient ï· Erection of the penis results from ________.a parasympathetic reflex ï· Why doesn't semen enter the ...
Phase 1: emission in which the vas deferens (the tubes that store and transport sperm from the testes) contract to squeeze the sperm toward the base of the penis through the prostate gland and into the urethra. The seminal vesicles release their part of the semen that combine with the sperm. The ejaculation is unstoppable at this stage. Phase 2: ejaculation in which the muscles at the base of the penis and urethra contract.