Semen has a(n) ___ pH

A. deepening of the voice: This is a secondary sex characteristic associated with androgens like testosterone, which cause the larynx to enlarge and the vocal cords to thicken. Estrogen does not induce these changes. In females, the voice remains higher because estrogen lacks the anabolic effect on laryngeal cartilage.

B. increased oiliness of the skin: Sebaceous gland activity is primarily stimulated by androgens in both males and females. High levels of estrogen typically have a moderating effect on skin oils and can lead to smoother skin texture. Increased sebum production and acne are more commonly associated with the hormonal shifts of puberty.

C. the reduction of progesterone: Estrogen does not typically reduce progesterone levels; in fact, estrogen often primes tissues by upregulating progesterone receptors. In the menstrual cycle, estrogen levels rise during the follicular phase, while progesterone levels rise later during the luteal phase. These hormones work synergistically to prepare the uterus for pregnancy.

D. growth of the breasts at puberty: Estrogen is the primary hormone responsible for the development of female secondary sexual characteristics. It stimulates the ductal system of the mammary glands and promotes the deposition of adipose tissue in the breasts. This process is a hallmark of female physical maturation during the pubertal transition.

E. growth of the larynx: As with the deepening of the voice, significant laryngeal growth is an androgenic effect seen predominantly in males. Estrogen does not cause the prominent thyroid cartilage growth known as the Adam's apple. Female laryngeal structures remain smaller and less prominent due to the lack of high testosterone levels.

A. hormones: Most small hormones, particularly steroid and peptide hormones not bound to large carrier proteins, are small enough to pass through the filtration membrane. They are often found in the initial filtrate in the capsular space. Their presence does not distinguish filtrate from plasma significantly.

B. plasma protein: The basement membrane and filtration slits are negatively charged and sized to repel large proteins like albumin. Consequently, the filtrate is essentially protein-free under normal conditions. The absence of these macromolecules is the primary chemical difference between plasma and glomerular filtrate.

C. glucose: Glucose is a small, uncharged molecule that moves freely across the filtration membrane into the capsular space. The concentration of glucose in the initial filtrate is identical to its concentration in the plasma. It is later reabsorbed entirely by the proximal convoluted tubules.

D. electrolytes: Ions such as sodium, potassium, and chloride are small enough to pass through the fenestrated capillaries and filtration slits without restriction. The electrolyte composition of the glomerular filtrate initially mirrors that of the blood plasma. Their balance is adjusted later during tubular processing.