Chapter 26 Fluid, Electrolyte, and Acid-Base Balance 1. 1) The body’s water volume is closely tied to the level of which of the following ions? A) calcium ions B) potassium ions C) hydrogen ions D) sodium ions Answer: D Page Ref: 1002-1004 2. 2) The term hypotonic hydration refers to ________. A) the feeling one might have after a long swim B) the unpleasant feeling people have after drinking too much liquor C) a condition that may result from renal insufficiency or drinking extraordinary amounts of water D) a condition that is caused by high levels of sodium in the extracellular fluid compartment Answer: C Page Ref: 1001 3. 3) Hypoproteinemia is a condition of unusually low levels of plasma proteins. This problem is often characterized by ________. A) tissue edema B) extreme weight loss C) extreme weight gain D) nerve damage Answer: A Page Ref: 1002 4. 4) Which of the following hormones is important in the regulation of sodium ion concentrations in the extracellular fluid? A) antidiuretic hormone B) erythropoietin C) aldosterone D) renin Answer: C Page Ref: 1004 5. 5) Atrial natriuretic peptide is a hormone that is made in the atria of the heart. The influence of this hormone is to ________. A) enhance atrial contractions B) activate the renin-angiotensin mechanism C) prevent pH changes caused by organic acids D) reduce blood pressure and blood volume by inhibiting sodium and water retention Answer: D Page Ref: 1004-1005 6. 6) Respiratory acidosis can occur when ________. A) a person consumes excessive amounts of antacids B) a person's breathing is shallow due to obstruction C) a runner has completed a very long marathon D) the kidneys secrete hydrogen ions Answer: B Page Ref: 1014

7. 7) Which of the following two organs function as the most important physiological buffer systems? A) the lungs and the kidneys B) the adrenal glands and the testes C) the thyroid gland and the heart D) the stomach and the liver Answer: A Page Ref: 1010-1011 8. 8) Which of the choices below is not an essential role of salts in the body? A) neuromuscular activity B) membrane permeability C) secretory activity D) anabolism of proteins Answer: D Page Ref: 1002 9. 9) Which of the choices below exerts primary control over sodium levels in the body? A) ADH B) aldosterone C) water levels D) glucocorticoids Answer: B Page Ref: 1004 10. 10) The fluid link between the external and internal environment is ________. A) plasma B) intracellular fluid C) interstitial fluid D) cerebrospinal fluid Answer: A Page Ref: 996 11. 11) Newborn infants have a relatively higher ________ content in their ECF than do adults. A) iron B) sodium C) magnesium D) bicarbonate Answer: B Page Ref: 1015 12. 12) Whereas sodium is found mainly in the extracellular fluid, most ________ is found in the intracellular fluid. A) iron B) chloride C) potassium D) magnesium Answer: C Page Ref: 997; Fig. 26.2 13. 13) Which of the following describes the distribution of sodium and potassium between cells and body fluids?

A) K+ mainly in the cells, Na+ in the body fluids B) Na+ mainly in the cells, K+ in the body fluids C) equal amounts of each ion in the cells and body fluids D) little of either in the cells, but large amounts of each in the body fluids Answer: A Page Ref: 997; Fig. 26.2 14. 14) Problems with fluid, electrolyte, and acid-base balance are particularly common in infants because of their ________. A) inefficient kidneys B) comparatively low metabolic rates C) low rate of insensible water loss D) low daily rate of fluid exchange Answer: A Page Ref: 1015 15. 15) The single most important factor influencing potassium ion secretion is ________. A) the potassium ion content in the renal tubule cells B) the pH of the ICF C) intracellular sodium levels D) potassium ion concentration in blood plasma Answer: D Page Ref: 1006 16. 16) The term alkaline reserve is used to describe the ________ buffer system. A) phosphate B) hemoglobin C) bicarbonate D) protein Answer: C Page Ref: 1009 17. 17) A falling blood pH and a rising partial pressure of carbon dioxide due to pneumonia or emphysema indicates ________. A) respiratory acidosis B) respiratory alkalosis C) metabolic acidosis D) metabolic alkalosis Answer: A Page Ref: 1014; Tbl. 26.2 18. 18) The movement of fluids between cellular compartments ________. A) requires active transport B) is regulated by osmotic and hydrostatic forces C) requires ATP for the transport to take place D) involves filtration Answer: B Page Ref: 998 19. 19) What hormone reduces blood pressure and blood volume by inhibiting nearly all events that promote vasoconstriction and sodium ion and water retention? A) ADH

B) aldosterone C) atrial natriuretic peptide D) thyroxine Answer: C Page Ref: 1005 20. 20) Which of the following is not a method for regulating the hydrogen ion concentration in blood? A) chemical buffer systems B) diet C) respiratory changes D) renal mechanism Answer: B Page Ref: 1009 21. 21) Which of the following is not a chemical buffer system? A) bicarbonate B) phosphate C) nucleic acid D) protein Answer: C Page Ref: 1009 22. 22) Extracellular fluid in the human body is composed of all of the following except ________. A) lymph and interstitial fluid B) blood plasma C) cerebrospinal fluid D) glucose Answer: D Page Ref: 997-998 23. 23) Which of the following statements is true regarding fluid shifts? A) Nonelectrolytes are the controlling factor in directing fluid shifts. B) Electrolytes are not as important as proteins in regulating fluid shifts in the body. C) Electrolytes have greater osmotic power than nonelectrolytes and therefore have the greatest ability to cause fluid shifts. D) There are always more positive electrolytes than negative in a solution; it is therefore impossible to follow fluid shifts. Answer: C Page Ref: 996-997 24. 24) Which of the following hormones is important in stimulating water conservation in the kidneys? A) aldosterone B) thymosin C) antidiuretic hormone D) atrial natriuretic peptide Answer: C Page Ref: 1000 25. 25) The maintenance of the proper pH of the body fluids may be the result of ________. A) the control of respiratory ventilation

B) the operation of the various buffer systems in the stomach C) the active secretion of OH- into the filtrate by the kidney tubule cells D) control of the acids produced in the stomach Answer: A Page Ref: 1010-1011 26. 26) Which of the following is not a disorder of water balance? A) excessive hydration due to excess ADH secretion B) hypotonic hydration, in which sodium content is normal but water content is high C) edema or tissue swelling, which is usually due to an increased capillary hydrostatic pressure D) excess water in interstitial spaces due to a low level of plasma proteins Answer: A Page Ref: 1001-1002 27. 27) The regulation of sodium ________. A) is due to specific sodium receptors in the hypothalamus B) is linked to blood pressure C) involves aldosterone, a hormone that increases sodium excretion in the kidneys D) involves hypothalamic osmoreceptor detection of ion concentration Answer: B Page Ref: 1004 28. 28) Select the correct statement about renal mechanisms of acid-base balance. A) The kidneys are not able to excrete phosphoric acid. B) Excreted hydrogen ions are unbound in the filtrate. C) Kidney tubule cells are able to synthesize bicarbonate ion. D) The kidneys are the most important mechanism for eliminating all bicarbonate ions. Answer: C Page Ref: 1011 29. 29) Blood analysis indicates a low pH, and the patient is breathing rapidly. Given your knowledge of acid-base balance, which of the following is most likely? A) respiratory acidosis B) metabolic acidosis C) metabolic alkalosis D) respiratory alkalosis Answer: B Page Ref: 1014; Tbl. 26.2 30. 30) A patient is breathing slowly and blood pH analysis indicates an abnormally high value. What is the likely diagnosis? A) respiratory acidosis B) metabolic acidosis C) metabolic alkalosis D) respiratory alkalosis Answer: C Page Ref: 1014; Tbl. 26.2 31. 31) One of the major physiological factors that triggers thirst is ________. A) a dry mouth from high temperatures B) becoming overly agitated

C) drinking caffeinated beverages D) a rise in plasma osmolality Answer: D Page Ref: 999 32. 32) Annie has just eaten a large order of heavily salted french fries, some pickled eggs, and some cheese. How will consuming this much salt affect her physiology? A) It will increase the osmolality of the blood. B) There will be a temporary increase in blood volume. C) She will experience hypotension. D) There will be a shift in the pH of her body fluids to the higher side of the pH scale. Answer: B Page Ref: 1002-1003 33. 33) The most important force causing net water flow across capillary walls is ________. A) osmotic pressure of plasma proteins B) hydrostatic pressure of capillary blood C) hydrostatic pressure of interstitial fluid D) intracellular hydrostatic pressure Answer: B Page Ref: 997-998 34. 34) Which of the following does not depend on the presence of electrolytes? A) membrane polarity B) neuromuscular excitability C) maintenance of osmotic relations between cells and ECF D) amount of body fat Answer: D Page Ref: 996 35. 35) The regulation of potassium balance ________. A) is not linked to sodium balance B) includes renal secretion, but never absorption C) is accomplished mainly by hepatic mechanisms D) involves aldosterone-induced secretion of potassium Answer: D Page Ref: 1005-1006 electrolytes

dissociate in water

nonelectrolytes

do not dissociate in water

extracellular

the fluid compartments outside the cell

intracellular

fluid compartments located within the cell

interstitial

spaces between the cells

magnesium excess hypermagnesemia

hypocalcemia

calcium depletion

hypernatremia

sodium excess

hyperkalemia

potassium excess

hyponatremia

sodium depletion

edema

an atypical accumulation of fluid in the interstitial space

hypoproteinemia

a condition of unusually low levels of plasma proteins resulting in tissue edema

Addison's Disease

A disorder entailing deficient mineralocorticoid hormone production by the adrenal cortex

alderosterone

Regulates sodium ion concentrations in the extracellular fluid

osmoreceptors

Special neurons in the hypothalmus that sense the ECF solute concentration and trigger or inhibit ADH release from the posterior pituitary gland

blood plasma

Sodium ions are highest in

intracellular fluid

Potassium ions are highest in

interstitial fluid

Bicarbonate ions are highest in

intracellular fluid

Proteins are highest in

Adipose tissue is one of the most hydrated of all tissues in the human body. False

The most abundant cation in intracellular fluid is sodium. False

Electrolytes determine most of the chemical and physical reactions of the body.

True

Solutes, regardless of size, are able to move freely between compartments because water carries them along the osmotic gradients.

False

The thirst center in the brain is located in the hypothalamus.

True

Dehydration can be caused by endocrine disturbances such as diabetes mellitus or diabetes insipidus.

True

It is impossible to overhydrate because people need as much water as they can drink to carry out ordinary body functions.

False

Water imbalance, in which output exceeds intake, causing an imbalance in body fluids, is termed dehydration.

True

Salts are lost from the body in perspiration, feces, and urine.

True

Hypoproteinemia reflects a condition of unusually high levels of plasma proteins and causes tissue edema. False

Although the sodium content of the body may be altered, its concentration in the ECF remains stable because of

True

immediate adjustments in water volume.

Sodium is pivotal to fluid and electrolyte balance and to the homeostasis of all body systems.

True

When aldosterone release is inhibited, sodium reabsorption cannot occur beyond the collecting tube.

True

Aldosterone stimulates the reabsorption of sodium while enhancing potassium secretion.

True

Pressure diuresis decreases blood volume and blood pressure.

True

Aldosterone is secreted in response to low extracellular potassium. False

To remain properly hydrated, water intake must equal water output.

True

The main way the kidney regulates potassium ions is to excrete them.

True

Atrial natriuretic peptide reduces blood pressure and blood volume by inhibiting nearly all events that promote vasodilation and potassium and water retention.

False

Premenstrual edema may be due to enhanced reabsorption of sodium chloride.

True

Heavy consumption of salt substitutes high in potassium can present a serious clinical problem when aldosterone

True

release is not normal.

Hypercalcemia causes muscle tetany. False

The two hormones responsible for the regulation of calcium are pituitary hormone and calcitonin. False

Calcitonin targets the bones and causes the release of calcium from storage when serum levels are low. False

The normal pH of blood is 7.35-7.45.

True

Most acidic substances (hydrogen ions) originate as by-products of cellular metabolism.

True

Weak acids are able to act as chemical buffering systems for the body because they partially dissociate.

True

The phosphate buffer system is relatively unimportant for buffering blood plasma.

True

The single most important blood buffer system is the bicarbonate buffer system.

True

One of the most powerful and plentiful sources of buffers is the protein buffer system.

True

As ventilation increases and more carbon dioxide is removed from the blood, the hydrogen ion concentration of

True

the blood decreases.

Regulation of the acid-base system is accomplished mainly through respiratory control, and the kidneys also play a small role.

False

Severe damage to the respiratory system rarely will result in acid-base imbalances. False

Respiratory acidosis results when lungs are obstructed and gas exchange is inefficient.

True

Prolonged hyperventilation can cause alkalosis.

True

Thirst is always a reliable indicator of body water need. False

Chapter 27 The Reproductive System 1. 1) The dartos and cremaster muscles are important to the integrity of the male reproductive system. Which of the following is true about the role they play? A) They contract to push sperm along the ductus deferens. B) They regulate the temperature of the testes. C) They are responsible for penile erection. D) They contract to allow ejaculation. Answer: B Page Ref: 1026 2. 2) The ability of sperm cells to move along the ductus deferens is due to ________. A) gravity B) peristaltic contractions C) enzymatic activity D) hormonal action Answer: B Page Ref: 1029-1030 3. 3) The ability of a male to ejaculate is due to the action of ________. A) parasympathetic nerves B) the dartos muscle C) luteinizing hormone D) the bulbospongiosus muscles Answer: D Page Ref: 1032 4. 4) The most important risk for testicular cancer in young males is ________. A) smoking B) a diet high in fat C) nondescent of the testes D) sexually transmitted infections Answer: C Page Ref: 1028 5. 5) Which of the following glands are responsible for 60% of the synthesis of semen? A) the seminal vesicles B) the bulbourethral glands C) the prostate D) the pituitary Answer: A Page Ref: 1030 6. 6) Which of the following hormones controls the release of anterior pituitary gonadotropins? A) LH B) FSH

C) GnRH D) testosterone Answer: C Page Ref: 1038-1039 7. 7) Development of male reproductive structures depends on which of the following events? A) that the female hormones are suppressed during pregnancy B) the suppression of inhibin C) secretion of male hormones prenatally and lasting into the first few months after birth D) that human gonadotropin be synthesized in the first week of the pregnancy Answer: C Page Ref: 1060 8. 8) The primary function of the uterus is to ________. A) protect the ovaries B) synthesize female hormones C) regulate the ovarian and menstrual cycles D) receive, retain, and nourish a fertilized ovum Answer: D Page Ref: 1042-1043 9. 9) Why is the blood-testis barrier important? A) because spermatozoa and developing cells produce surface antigens that are recognized as foreign by the immune system B) because some blood contents are toxic to the spermatozoa C) because immature sperm cells lose their motility when they encounter any blood component D) Actually, the blood-testis barrier has no function. Answer: A Page Ref: 1038 10. 10) The structures that receive the ovulated oocyte, providing a site for fertilization, are called the ________. A) Graafian follicles B) fallopian tubes C) infundibula D) fimbriae Answer: B Page Ref: 1042 11. 11) If gametes were diploid like somatic cells, how many chromosomes would the zygote contain? A) twice the diploid number, and with every succeeding generation, the chromosome number would continue to double and normal development could not occur B) triple the diploid number, and with every succeeding generation, the chromosome number would continue to triple and normal development would not occur C) half the diploid number with no change in development D) There is no relationship between gametes and somatic cells. Answer: A Page Ref: 1033 12. 12) Human egg and sperm are similar in that ________. A) about the same number of each is produced per month B) they have the same degree of motility

C) they have the same number of chromosomes D) they are about the same size Answer: C Page Ref: 1032 13. 13) The constancy of the chromosome number from one cell generation to the next is maintained through ________. A) mitosis B) meiosis C) cytokinesis D) DNA synthesis Answer: B Page Ref: 1033 14. 14) Fertilization generally occurs in the ________. A) ovary B) uterus C) vagina D) fallopian tubes Answer: D Page Ref: 1042 15. 15) Spermiogenesis involves the ________. A) formation of four haploid cells from a spermatogonium B) movement of sperm in the female genital tract C) formation of a functional sperm by the stripping away of superfluous cytoplasm D) sequence of events in the rete testis Answer: C Page Ref: 1037 16. 16) All of the following can be considered male secondary sex characteristics except the ________. A) development of body hair B) lowering of the voice C) development of testes as opposed to ovaries D) increasing mass of the skeleton Answer: C Page Ref: 1040 17. 17) In humans, separation of the cells at the two-cell state following fertilization may lead to the production of twins, which in this case would be ________. A) dizygotic B) identical C) fraternal D) of different sexes Answer: B Page Ref: 1052 18. 18) Characteristics of the mature sperm include the ________. A) presence of two X chromosomes in approximately half the sperm B) presence of Y chromosomes in approximately half the sperm

C) absence of an acrosome D) absence of coiled mitochondria Answer: B Page Ref: 1037 19. 19) How do the testes respond to exposure to excessive body warmth? A) They move close to the pelvic cavity. B) They move away from the pelvic cavity. C) Excessive warmth has no effect on the testicles because of their location in the scrotum. D) Excessive warmth is actually beneficial in that it speeds up the maturation of sperm. Answer: B Page Ref: 1025-1026 20. 20) Effects of estrogen include ________. A) increased oiliness of the skin B) deepening of the voice C) growth of the breasts at puberty D) growth of the larynx Answer: C Page Ref: 1056; Tbl. 27.1 21. 21) Secretion of progesterone stimulates ________. A) contraction of uterine muscles B) preparation of the mammary glands for lactation C) secretory activity of the uterine myometrium D) development of the female secondary sex characteristics Answer: B Page Ref: 1056; Tbl. 27.1 22. 22) Which of the following statements about sperm is not true? A) They contain very little cytoplasm or stored nutrients. B) They are sluggish in an alkaline environment. C) The acrosome is produced by the Golgi apparatus and contains hydrolytic enzymes. D) The sperm midpiece consists of mitochondria spiraled tightly around the contractile filaments of the tail. Answer: D Page Ref: 1033, 1037-1038 23. 23) The cells that produce testosterone in the testis are called ________. A) spermatocytes B) spermatogonia C) sustentacular cells D) interstitial cells Answer: D Page Ref: 1026 24. 24) The testicular cells that construct the blood-testis barrier are the ________. A) spermatocytes B) spermatogonia C) sustentacular cells D) interstitial cells

Answer: C Page Ref: 1037-1038 25. 25) Which of the following occurs as a result of undescended testes? A) Male sex hormones will not be circulated in the body. B) Sperm will have no means of exit from the body. C) Inadequate or nonviable sperm will be produced. D) Inadequate blood supply will retard the development of the testes. Answer: C Page Ref: 1062 26. 26) Erection of the penis results from ________. A) a sympathetic reflex B) parasympathetic activation of the bulbourethral glands C) dilation of the veins in the penis D) a parasympathetic reflex Answer: D Page Ref: 1031-1032 27. 27) Which is not a part of the proliferative phase of the female menstrual cycle? A) late in this phase, cervical mucus becomes thin and crystalline B) vesicular follicle growth C) corpus luteum D) development of endometrial cells Answer: C Page Ref: 1052, 1054 28. 28) Which of the choices below is not a function of the vagina? A) serves as a ageway for the primary oocyte B) serves as a ageway for menstrual flow C) is the birth canal D) receives semen from the penis during sexual intercourse Answer: A Page Ref: 1044-1045 29. 29) Select the correct statement about male sexual response. A) Sympathetic impulses are responsible for causing penile arteriolar dilation, resulting in erection. B) Erection is the result of vascular spaces in the erectile tissues filling with blood. C) Expansion of the penile tissues results in dilation of the venous outflow. D) Ejaculation is the result of parasympathetic stimulation. Answer: B Page Ref: 1031 30. 30) Which of the choices below is not a function of testosterone? A) stimulates the male pattern of development B) contributes to male sexual behavior and spermatogenesis C) stimulates protein synthesis D) stimulates mammary gland development Answer: D Page Ref: 1039; Tbl. 27.1

31. 31) Which male hormone inhibits the secretion of FSH? A) ACTH B) inhibin C) ICSH D) testosterone Answer: B Page Ref: 1038-1039 32. 32) During the secretory phase of the menstrual cycle ________. A) LH reaches its highest levels B) progesterone levels are at their highest C) estrogen reaches its highest levels D) the Graafian follicle forms Answer: B Page Ref: 1056 33. 33) Select the correct statement about the uterine cycle. A) The menstrual phase of the cycle is from day 1 to day 8. B) During the secretory phase, estrogen levels are at their highest. C) During the proliferative phase, levels of progesterone rise as the follicle begins to produce more hormone. D) If fertilization occurs, the corpus luteum is maintained by a hormone secreted by the developing embryo. Answer: D Page Ref: 1054-1056 34. 34) Which of the choices below is not a part of the brain-testicular axis? A) hypothalamus B) anterior pituitary gland C) thalamus D) testes Answer: D Page Ref: 1038 35. 35) Which of the following statements is true concerning the mammary glands of both males and females? A) Both sexes are equally prone to breast cancer. B) All lumps identified in breast tissue are malignant. C) The only time hormones target breast tissue is during pregnancy and lactation. D) The mammary glands are modified sweat glands that are actually part of the integumentary system. Answer: D Page Ref: 1047-1048 36. 36) Normally menstruation occurs when ________. A) blood levels of FSH fall off B) blood levels of estrogen and progesterone decrease C) blood levels of estrogen and progesterone increase D) the corpus luteum secretes estrogen Answer: B Page Ref: 1056

37. 37) The basic difference between spermatogenesis and oogenesis is that ________. A) during spermatogenesis two more polar bodies are produced B) the mature ovum is n, while the sperm is 2n C) in oogenesis, one mature ovum is produced, and in spermatogenesis four mature sperm are produced from the parent cell D) spermatogenesis involves mitosis and meiosis, but oogenesis involves meiosis only Answer: C Page Ref: 1049 38. 38) Occasionally three polar bodies are found clinging to the mature ovum. One came from an unequal division of the ovum, but from where did the other two arise? A) There were originally four polar bodies and one disappeared. B) One is an undeveloped primary oocyte that failed to mature. C) The first polar body has also divided to produce two polar bodies. D) What you really see are two polar bodies and the sperm that will fertilize the egg. Answer: C Page Ref: 1049 39. 39) Which of the following will occur after ovulation? A) The corpus luteum secretes estrogen only. B) The endometrium enters its secretory phase. C) The secretion of anterior pituitary gonadotropins is enhanced. D) The corpus luteum prepares to become a corpus albicans. Answer: B DiPage Ref: 1052 40. 40) Why doesn’t semen enter the urinary bladder during ejaculation? A) There is no common duct between the reproductive system and the urinary system. B) There is no urge to urinate during sexual intercourse because of the suppression of LH by testosterone buildup in the blood. C) The smooth muscle sphincter at the base of the urinary bladder closes. D) Ejaculation is a parasympathetic reflex resulting in no response by urinary contraction muscles. Answer: C Page Ref: 1032 41. 41) Spermatogenesis ________. A) is the process of releasing mature sperm cells into the lumen of the seminiferous tubule B) involves a kind of cell division limited to the gametes C) results in the formation of diploid cells D) uses mitosis to produce gamete cells Answer: B Page Ref: 1032-1033 42. 42) Which hormone is absolutely necessary for ovulation to occur? A) LH B) FSH C) progesterone D) estrogen Answer: A Page Ref: 1052-1053

43. 43) The brain-testicular axis ________. A) is the tight relationship between the cortex and the control of testicular function B) involves FSH and LH release C) involves posterior pituitary release of regulating hormones D) involves a positive loop control of spermatogenesis Answer: B Page Ref: 1038 44. 44) Select the correct statement about testosterone control. A) GnRH from the hypothalamus causes FSH and LH release from the anterior pituitary. B) FSH stimulates testicular production of testosterone. C) Inhibin and testosterone exert positive on the hypothalamus and pituitary. D) The pineal gland is believed to be the gland that exerts the most influence in testosterone control. Answer: A Page Ref: 1039 45. 45) Which of the following is a correct statement about uterine tubes? A) The ampulla is the narrow constricted region. B) The infundibulum is the funnel-shaped region near the ovary. C) The isthmus is the normal site of fertilization. D) The mesometrium s the uterine tubes along their entire length. Answer: B Page Ref: 1042 46. 46) Select the correct statement about the hormonal events of the ovarian cycle. A) Rising levels of estrogen start follicle development. B) High estrogen levels result in a surge of LH release. C) The follicle begins to secrete progesterone in response to estrogen stimulation. D) The LH surge stimulates further development of the secondary oocyte. Answer: B Page Ref: 1052-1054 47. 47) Which of these statements about sexually transmitted infections is false? A) Chlamydia is caused by bacteria that can often be asymptomatic or bring on a wide variety of symptoms. B) Gonorrhea is caused by a bacterium that can bring on painful discharges in males. C) Syphilis is caused by a virus that may lead to death if untreated. D) Genital herpes is caused by a virus that may cause intermittent lesions. Answer: C Page Ref: 1058-1059 48. 48) Which of the following statements about spermatogenesis is not true? A) The spermatogonium forms the primary spermatocyte. B) The primary spermatocyte forms two secondary spermatocytes. C) The secondary spermatocytes each form two spermatids. D) Each spermatid forms two sperm. Answer: D Page Ref: 1033, 1037 49. 49) A boy who has not ed through puberty sustains an injury to his anterior pituitary such that FSH is no longer released, but LH is normal. After he grows to maturity, one would expect that he

would ________. A) be sterile B) not develop secondary sex characteristics C) be impotent (unable to have an erection) D) have impaired function of interstitial cells Answer: A Page Ref: 1038-1039 50. 50) Which of the following statements about the female reproductive process is not true? A) Fertilization usually occurs in the fallopian tube. B) Ovulation usually occurs 14 days after the beginning of menses. C) Rebuilding the endometrium is under the control of prolactin. D) The monthly discharge of the uterus (menses) is initiated by the decrease in secretion of female hormones. Answer: C Page Ref: 1052-1054 51. 51) A low secretion of luteinizing hormone (LH) in the normal male adult would cause ________. A) decreased testosterone secretion B) excessive beard growth C) increased spermatogenesis D) shrinkage of the anterior pituitary gland Answer: A Page Ref: 1038-1039 52. 52) All of the following statements referring to the uterine cycle are true except ________. A) FSH and LH directly promote development of the uterine endometrium B) estrogen is secreted by the developing follicle in the follicular phase of the cycle C) the corpus luteum is formed from the ruptured follicle after ovulation D) a decrease in the levels of ovarian hormones signals menstruation Answer: A Page Ref: 1052-1054 53. 3) Which of the following phases or processes in the monthly reproductive cycle of the female occur simultaneously? A) maximal LH secretion and menstruation B) maximal steroid secretion by the corpus luteum and menstruation C) early follicular development and the secretory phase in the uterus D) regression of the corpus luteum and a decrease in ovarian progesterone secretion Answer: D Page Ref: 1054, 1056 54. 54) The duct system of the male reproductive system includes the ________. A) epididymis B) urethra C) ductus deferens D) corpus spongiosum Answer: D Page Ref: 1028 55. 55) An ovulating oocyte is actually activated by hormones about ________ days before ovulation. A) 14

B) 28 C) 85 D) 110 Answer: D Page Ref: 1054 56. 56) Prostate cancer is _______. A) the number-one cause of death in men B) sometimes a slow-growing cancer that may never represent a threat to the patient C) most common in Asians D) often the result of a distortion of the urethra Answer: B Page Ref: 1030-1031

Chapter 28 Pregnancy and Human Development 1. Match the following: A) Capacitation B) Fertilization C) Implantation D) Gastrulation E) Cleavage 2. 11) Leads to the development of a morula and then a blastocyst. E Page Ref: 1075 3. 12) Embedding of the blastocyst in the uterine wall. C Page Ref: 1076 4. 13) Leads to the formation of the first cell of the new individual. B Page Ref: 1072 5. 14) Leads to the establishment of the three primary germ layers. D Page Ref: 1081 6. 15) Leads to enhancement of sperm motilityand increasing membrane fragility to enable enzyme release from acrosomes. A Page Ref: 1072-1073 7. True/False Questions 1) Conceptus is a term used to describe the developing human offspring. Answer: TRUE Page Ref: 1072 8. 2) The period from fertilization through week eight is called the embryonic period.

Answer: TRUE Page Ref: 1072 9. 3) Fertilization occurs while the egg is still in the ovarian follicle. Answer: FALSE Page Ref: 1072 10. 4) Freshly deposited sperm are not capable of penetrating an oocyte. Answer: TRUE Page Ref: 1072 11. 5) By 72 hours after fertilization, the egg has divided into more than 160 cells and is called the morula. Answer: FALSE Page Ref: 1075 12. 6) Implantation begins six to seven days after ovulation. Answer: TRUE Page Ref: 1076 13. 7) A pregnancy test involves antibodies that detect GH levels in a woman's blood or urine. Answer: FALSE Page Ref: 1077 14. 8) The body systems of the developing embryo are present in at least rudimentary form at eight weeks. Answer: TRUE Page Ref: 1087; Fig. 28.1 15. 9) Of the three germ layers, the mesoderm forms the most body parts. Answer: TRUE Page Ref: 1084-1085 16. 10) A pregnant woman urinates more often than usual because the uterus compresses the bladder, and she must also dispose of fetal metabolic wastes. Answer: TRUE Page Ref: 1090 17. 11) The "fluid-filled, hollow ball of cells" stage of development is the blastocyst. Answer: TRUE Page Ref: 1075 18. 12) The embryonic stage lasts until the end of the eighth week. Answer: TRUE Page Ref: 1072 19. 13) The embryo is directly enclosed in and protected by the amnion. Answer: TRUE Page Ref: 1080 20. 14) In fetal circulation, one way in which blood byes the nonaerated lungs is by way of the foramen ovale. Answer: TRUE Page Ref: 1085 21. 15) An episiotomy is an incision made to widen the vaginal orifice, aiding fetal expulsion.

Answer: TRUE Page Ref: 1091 22. 16) The placenta and its attached fetal membranes are collectively called the afterbirth. Answer: TRUE Page Ref: 1092 23. 17) Human placental lactogen initiates labor. Answer: FALSE Page Ref: 1091 24. 18) Surfactant production in premature infants is rarely a factor in providing normal respiratory activity. Answer: FALSE Page Ref: 1093 25. 19) A blastocyst is a hollow ball of cells, while the morula is a solid ball of cells. Answer: TRUE Page Ref: 1075 26. 20) A zygote is usually formed within the uterus. Answer: FALSE Page Ref: 1072 1. 1) Cells on the dorsal surface of the two-layered embryonic disc migrate to form a raised groove known as the ________. A) blastocyst B) amnion formation C) germ cell formation D) primitive streak Answer: D Page Ref: 1081 2. 2) The result of polyspermy in humans is ________. A) multiple births B) a nonfunctional zygote C) interruption of meiosis D) mitotic insufficiency Answer: B Page Ref: 1073 3. 3) It is impossible for sperm to be functional (able to fertilize the egg) until after ________. A) the tail disappears B) they become spermatids C) they undergo capacitation D) they have been stored in the uterus for several days Answer: C Page Ref: 1072-1073 4. 4) Milk ejection or letdown reflex is stimulated by which of the following hormones associated with pregnancy? A) inhibin B) oxytocin

C) prolactin D) gonadotropin Answer: B Page Ref: 1093-1095 5. 5) Estrogen and progesterone maintain the integrity of the uterine lining and prepare the mammary glands to secrete milk. Which of the following structures makes this possible during the first three months of pregnancy? A) the amnion B) the chorion C) corpus luteum D) corona radiata Answer: C Page Ref: 1078 6. 6) The placenta, a vitally important metabolic organ, is made up of a contribution from mother and fetus. Which portion is from the fetus? A) chorion B) umbilicus C) yolk sac D) amnion Answer: A Page Ref: 1078 7. 7) Relaxin is a hormone produced by the placenta and ovaries. The function of this hormone is to ________. A) block the pain of childbirth B) ensure the implantation of the blastula C) relax the pubic symphysis D) prevent morning sickness Answer: C Page Ref: 1089 8. 8) Proteases and acrosin are enzymes. How do they function in reproduction? A) They neutralize the mucous secretions of the uterine mucosa. B) They direct the sperm to the egg through chemical messengers. C) They act to break down the protective barriers around the egg, allowing the sperm to penetrate. D) Their function is unknown. Answer: C Page Ref: 1073 9. 9) Which of the following is not a germ layer? A) ectoderm B) mesoderm C) epiderm D) endoderm Answer: C Page Ref: 1081 10. 10) The formation of endodermal and ectodermal germ layers occurs at ________. A) fertilization B) cleavage

C) gastrulation D) blastula formation Answer: C Page Ref: 1081 11. 11) Which hormone maintains the viability of the corpus luteum? A) estrogen B) progesterone C) human chorionic gonadotropin D) human placental lactogen Answer: C Page Ref: 1077 12. 12) Which of the following is a highly unlikely method of producing a child? A) embryo transfer B) ectopic implantation C) in vitro fertilization D) gamete intrafallopian transfer Answer: B Page Ref: 1096 13. 13) Which of the following is not a correct matching of a fetal structure with what it becomes at birth?

ntum venosum Answer: B Page Ref: 1093 14. 14) Implantation involves ________. A) placenta completion B) formation of germ layers C) fusion of egg and sperm D) embedding of the blastocyst in the uterine wall Answer: D Page Ref: 1076 15. 15) The umbilical arteries carry ________. A) waste products to the placenta B) oxygen and food to the fetus C) oxygen and metabolic wastes to the placenta D) oxygen and waste products to the fetus Answer: A Page Ref: 1084-1085 16. 16) The correct sequence of preembryonic structures is ________. A) zygote, blastocyst, morula B) zygote, morula, blastocyst C) blastocyst, morula, zygote D) morula, zygote, blastocyst

Answer: B Page Ref: 1073, 1075 17. 17) Which of the following is not assessed as part of the Apgar score? A) heart rate B) respiration C) muscle tone D) temperature Answer: D Page Ref: 1093 18. 18) Hormones concerned with events of lactation include ________. A) estrogen B) oxytocin C) progesterone D) hCG Answer: B Page Ref: 1093-1094 19. 19) Initially, the implanted embryo obtains its nutrition by ________. A) simple diffusion of nutrients from the uterine secretions B) nutrient stores in the embryonic cells C) the blood supply of the placenta D) digestion of endometrial cells Answer: D Page Ref: 1078 20. 20) Onset of labor may be a result of all of the following factors except ________. A) secretion of oxytocin B) high estrogen levels C) aspirin and similar drugs D) contraction-related increased emotional and physical stress Answer: C Page Ref: 1091 21. 21) Select the correct statement about fertilization. A) Both spermatozoa and the ovulated secondary oocyte remain viable for about 72 hours in the female reproductive tract. B) Millions of sperm cells are destroyed by the vagina's acidic environment. C) If estrogen is present, the pathway through the cervical opening is blocked from sperm entry. D) Once inside the uterus, most sperm cells are protected and remain viable. Answer: B Page Ref: 1072-1073 22. 22) Shortly after implantation ________. A) maternal blood sinuses bathe the inner cell mass B) myometrical cells cover and seal off the blastocyst C) the trophoblast forms two distinct layers D) the embryo gastrulates (within 3 days) Answer: C Page Ref: 1077

23. 23) The dorsal surface cells of the inner cell mass form ________. A) a structure called the embryonic disc B) one of the fetal membranes C) the primitive streak D) the notochord Answer: C Page Ref: 1081 24. 24) Muscle tissue is formed by the ________. A) mesoderm B) ectoderm C) endoderm D) epiderm Answer: A Page Ref: 1084; Fig. 28.13 25. 25) Neural tissue is formed by the ________. A) epiderm B) endoderm C) mesoderm D) ectoderm Answer: D Page Ref: 1083; Fig. 28.13 26. 26) The trophoblast is mostly responsible for forming the ________. A) allantois B) archenteron C) placental tissue D) lining of the endometrium Answer: C Page Ref: 1075 27. 27) The cardiovascular system of a newborn must be adjusted after the infant takes its first breath. Which of the following is also true? A) The foramen ovale between the atria of the fetal heart closes at the moment of birth. B) The ductus venosus is disconnected at the severing of the umbilical cord and all visceral blood goes into the vena cava. C) The urinary system is activated at birth. D) The ductus arteriosus constricts and is converted to the ligamentum arteriosum. Answer: D Page Ref: 1092-1093 28. 28) Sperm move to the uterine tube through uterine contractions and the energy of their own flagella. What other factor is involved in sperm movement? A) hormonal attraction to the ova B) reverse peristalsis of the uterus and uterine tubes C) the cilia on the apex of the cells lining the endometrium D) the increased temperature in the vagina, which stimulates sperm motility Answer: B Page Ref: 1072-1073

29. 29) At which stage of labor is the "afterbirth" expelled? A) dystocia B) expulsion C) placental D) full dilation Answer: C Page Ref: 1092 30. 30) Which hormone is not produced by the placenta? A) human placental lactogen B) human chorionic thyrotropin C) relaxin D) inhibin Answer: D Page Ref: 1078 31. 31) During which stage of labor is the fetus delivered? A) dilation stage B) expulsion stage C) placental stage D) gastrula stage Answer: B Page Ref: 1091 32. 32) Implantation of the blastocyst is the result of all of the following except ________. A) phagocytosis by the trophoblast cells B) proteolytic enzymes produced by the trophoblast cells C) settling of the blastocyst onto the prepared uterine lining D) adherence of the trophoblast cells to the endometrium Answer: A Page Ref: 1076-1077 33. 33) Cleavage as part of embryonic development is distinctive because it involves ________. A) cell division by mitosis with little or no growth between successive divisions B) the fusion of gametes C) splitting the cell into two separate cells D) meiosis Answer: A Page Ref: 1075 34. 34) Which of the following is true in reference to what may through the placental barriers? A) nutrients and respiratory gases only B) hormones, blood cells, and nutrients C) nutrients, respiratory gases, wastes, and alcohol D) respiratory gases, hormones, nutrients, and blood cells Answer: C Page Ref: 1078 35. 35) Which of the following is not usually considered a teratogen? A) aspirin B) wine

C) thalidomide D) German measles Answer: A Page Ref: 1085 36. 36) Derivatives of the ectoderm include ________. A) serosae of the ventral body cavity B) epithelium of the reproductive tract C) epithelium of the pineal and pituitary glands D) connective tissues Answer: C Page Ref: 1081, 1083 37. 37) Derivatives of the mesoderm include ________. A) all nervous tissue B) endothelium of blood and lymph vessels C) glandular derivatives of the digestive tract D) epithelium of the digestive tract Answer: B Page Ref: 1084 38. 38) Derivatives of the endoderm include ________. A) epithelium of the respiratory tract B) synovial membranes of the ts C) blood, bone marrow, and lymphoid tissue D) organs of the urogenital system Answer: A Page Ref: 1083-1084 39. 39) Developmental events during weeks 9-12 include ________. A) sex readily detected from the genitals B) the cardiovascular system becoming fully functional C) head larger than body D) fetal position assumed Answer: A Page Ref: 1088; Fig. 28.1 40. 40) Which of the choices below occurs if fertilization of the ovum occurs and implantation takes place? A) The corpus luteum is maintained until the placenta takes over its hormone-producing functions. B) The corpus luteum degenerates and becomes the corpus albicans. C) The ovarian cycle begins. D) Increased levels of FSH will be produced. Answer: A Page Ref: 1076-1077 41. 41) Select the correct statement about the special fetal blood vessels. A) The distal parts of the umbilical arteries form the superior vesical arteries. B) The fossa ovalis becomes the foramen ovale. C) The umbilical vein becomes the ligamentum teres. D) The hepatic portal vein forms from the umbilical artery.

Answer: C Page Ref: 1084-1085 42. 42) Which of the following statements about the events of fertilization is not true? A) The two pronuclei divide. B) The head of the sperm forms the male pronucleus. C) The secondary oocyte completes the second meiotic division. D) Proteases and acrosin proteinases of the sperm disperse the cells of the corona radiata of the oocyte. Answer: A Page Ref: 1073 43. 43) The decidua basalis is ________. A) destined to remain in the uterus after the birth of the infant B) located between the developing embryo and the myometrium C) not a maternal contribution to the placenta D) the tissue that surrounds the uterine cavity face of the implanted embryo Answer: B Page Ref: 1078; Fig. 28.1

Chapter 29 Heredity 1. 1) Two alleles expressing exactly the same information for a trait are designated as ________. A) hemizygous B) monogamous C) heterozygous D) homozygous Answer: D 2. 2) Dominant alleles are so called because under most circumstances they ________. A) code only for tallness and dark skin B) suppress the expression of other alleles C) code for genes that are never considered lethal D) code for most phenotypic and genotypic expressions of a trait Answer: B 3. 3) Recessive genes are usually expressed in humans only when ________. A) they are coding for skin color B) they are coding for genetic diseases C) the organism is in the embryonic stage D) both alleles are exactly the same, or homozygous Answer: D 4. 4) Those characteristics that can be determined on superficial inspection of an individual are known as ________. A) genotypic B) polygenic C) polyspermic D) phenotypic

Answer: D 5. 5) The number of gamete types from independent assortment of the homologues during meiosis in humans would be: A) 21 × 2 (42) B) 232 (529) C) 223 (78 million) D) 46 × 2 (92) Answer: C 6. 6) A female infant is born with several hundred oocytes, each one genetically unique. This is due to ________. A) mutation B) recessive inheritance C) chromosome deletion D) independent assortment and random crossover Answer: D 7. 7) If we are to consider the variation resulting only from independent assortment and random fertilization, any resulting offspring represents about one out of ________. A) 64 zygotes possible B) 23,000 zygotes possible C) 64,000 zygotes possible D) 72 trillion zygotes possible Answer: D 8. 8) Mitosis differs from meiosis because in meiosis we observe ________. A) tetrads B) chromatids C) centromeres D) homologues Answer: A 9. 9) The reason recessive genetic disorders are more frequent than disorders inherited as dominant is that ________. A) dominant genetic disorders are never expressed in males B) people carrying dominant genetic disorders always die before birth C) carriers may them on to their offspring, unaware that they are carriers D) recessive genetic disorders are limited to persons of the same ethnicity Answer: C 10. 10) The gene responsible for the condition known as sickle-cell anemia demonstrates ________. A) incomplete dominance B) a dominant genetic disorder C) a sex-linked genetic disorder D) a recessive genetic disorder

Answer: A 11. 11) An example of multiple allele inheritance is ________. A) the ABO blood group B) the appearance of freckles on the skin C) the appearance of birthmarks on the skin D) hair that seems to have several shades of a color Answer: A 12. 12) Which of the following is true concerning environmental influence on genetic expression? A) It is impossible to alter in any way the expression of a gene in humans. B) The only time a gene can be influenced by environmental factors is in the second trimester of the pregnancy. C) Environmental factors determine the way in which 90 percent of our genes are expressed. D) Drugs and nutrition can alter normal gene expression. Answer: D 13. 13) Sex chromosomes of a normal male are ________. A) XX B) YY C) XY D) Any of these, depending on the father Answer: C 14. 14) A woman has blond hair and brown eyes. This statement is best described as indicating ________. A) allelic pairs B) recessive traits C) phenotype D) genotype Answer: C 15. 15) A chromosomal aberration in which part of a chromosome is lost is known as ________. A) deletion B) inversion C) translocation D) crossing over Answer: A 16. 16) Inheritance of stature (height) in humans is probably due to ________. A) polyploidy B) polymorphism C) incomplete dominance D) polygene inheritance Answer: D

17. 17) Huntingtonʹs disease is an example of a(n) ________ gene. A) dominant B) recessive C) delayed-action D) incomplete dominant Answer: C 18. 18) An individual who is heterozygous for a particular trait, yet expresses both alleles of that trait, is an example of ________. A) dominance B) recessive inheritance C) incomplete dominance D) sex-linked inheritance Answer: C

19.

Figure 29.1 19) Given the information in Figure 29.1, what would the genotype of the offspring designated by the blank square?

A) TT B) Tt C) tt D) Dt Answer: C 20. 20) Given the information in Figure 29.1, what would the genotype ratio be for the offspring? A) 1:1:1:1 B) 1:2:1 C) 1:3 D) 4:0 Answer: B 21. 21) Given the information in Figure 29.1, what is the phenotype ratio (assuming C is dominant and there is no incomplete dominance)? A) 1:1:1:1 B) 1:2:1

C) 1:3 D) 4:0 Answer: C 22. 22) Given the information in Figure 29.1, if C were an incomplete dominant trait, what would the phenotype ratio be for the offspring? A) 1:1:1:1 B) 1:2:1 C) 1:3 D) 4:0 Answer: B 23. 23) ________ is the most common type of fetal testing. A) Blood chemistry B) Amniocentesis C) A DNA probe D) CVS Answer: B 24. 24) Huntingtonʹs disease involves ________. A) hypersecretion of growth hormone B) the presence of an extra chromosome C) degeneration of the basal nuclei of the brain D) hyposecretion of thyroxine Answer: C 25. 25) One possible scientific explanation for siblings having very different skin color is ________. A) polygene inheritance, which results in continuous phenotypic variation between extremes B) that some people may be in the sun longer than others C) that the gene for dark skin is dominant over the gene for light skin, and some offspring inherit chromosomes with one of each allele D) There is no explanation for the variation Answer: A 26. 26) Which of the following statements is true concerning screening? A) Screening is illegal in over half of the world. B) Screening can be done only in the first trimester of pregnancy. C) Genetic screening is rarely done because it yields very little accurate information. D) Screening can be done before conception by carrier recognition or during fetal testing. Answer: D 27. 27) The diploid genome contains chromosomes from ________. A) the father only B) the mother only C) each parent, and it synthesizes others D) both the mother and father, but only about half of the genome from each

Answer: D 28. 28) Amyʹs hand was exposed to X rays. A gene in a skin cell of her hand mutated. This mutant gene ________. A) will definitely cause skin cancer B) will replicate itself and be ed on to Amyʹs children C) will not form an exact duplicate of itself when the cell divides D) will replicate itself when the cell divides but will not be ed on to Amyʹs offspring Answer: D 29. 29) Select the incorrect statement about Chromosomes and genes. A) Genes on neighboring but different chromosomes are called linked. B) Recombinant chromosomes have segments of DNA from each parent on the same chromosome. C) The longer a chromosome, the more crossovers are expected. D) A personʹs genetic makeup is referred to as his or her genotype. Answer: A 30. 30) The main way a recessive allele would be expressed even when only one copy is present would be ________. A) dominance B) recessive inheritance C) sex-linked inheritance D) incomplete dominance Answer: C 31. 31) A couple whose blood types are A (IAi) and B (IBi) may have a child with which of the following blood types? A) AB only B) A and B only C) A, B, AB, and O D) AB and O only Answer: C 32. 32) Gene mutations in the sex chromosomes of the human would tend to become visibly expressed ________. A) more frequently in males B) more frequently in females C) equally frequently in both sexes D) in neither males or females Answer: A 33. 33) For which of the following are newborn infants not routinely screened at birth? A) PKU B) color blindness C) imperforate anus D) congenital hip dysplasia

Answer: B 1. Matching Questions Match the following: 1) Actual genetic makeup. 2) A chromosome pair that may be very different in size. 3) Genes not expressed unless they are present in homozygous condition. 4) Situation in which an individual has identical alleles for a particular trait. A) Recessive B) Sex chromosomes C) Genotype D) Homozygous 1) C 2) B 3) A 4) D 2. 5) Lack of skin pigmentation. 6) Rare type of dwarfism resulting from an impaired ability of the fetus to form cartilage bone. 7) An unremitting, fatal nervous system disease involving degeneration of the basal nuclei. 8) A condition of excessive mucus production. Diff: 2 Page Ref: 1151 9) A disorder of brain lipid metabolism. A) Achondroplasia B) Albinism C) Huntingtonʹs disease D) Tay-Sachs disease E) Cystic fibrosis 5) B 6) A

7) C 8) E 9) D 3. 10) Genes for the same trait that have different expressions. 11) The gene allele that suppresses or masks the expression of the other allele. 12) Situation in which an individual has different alleles making up the genotype for a particular trait. 13) Chromosomes regulating most body characteristics. A) Heterozygous B) Allele C) Dominant D) Autosomes 10) B 11) C 12) A 13) D 4. True/False Questions 1) When two genes are on the same chromosome, they are considered linked. Answer: TRUE 5. 2) The X chromosome is considerably larger than the Y chromosome. Answer: TRUE 6. 3) Incomplete dominance is more uncommon in humans. Answer: TRUE 7. 4) Some segments of the Y chromosome have no counterpart on the X chromosome. Answer: TRUE 8. 5) Chromosomes that are not directly involved with sex determination are called sex-linked. Answer: FALSE 9. 6) Hereditary characteristics are transmitted to offspring by genes. Answer: TRUE 10. 7) Alleles may code for alternative expressions of a genetic trait. Answer: TRUE 11. 8) Hemophilia is an X-linked condition caused by a recessive gene. Answer: TRUE

12. 9) Environmentally produced phenotypes that mimic conditions that may be caused by genetic mutation are called phenocopies. Answer: TRUE 13. 10) Most genetic disorders are inherited through dominant genes. Answer: FALSE 14. 11) A Punnett square is a diagram that may be used to figure out the possible combinations of genes for a trait. Answer: TRUE 15. 12) The term lethal dominant gene indicates that the gene causes death only when the individual is homozygous. Answer: FALSE 16. 13) In incomplete dominance, the heterozygote has a phenotype intermediate between that of homozygous-dominant and homozygous-recessive individuals. Answer: TRUE 17. 14) The two equally useful avenues for detecting carriers are pedigrees and the use of Punnett squares. Answer: FALSE 18. 15) Normal vision is dictated by the autosomal dominant genes. Answer: FALSE 19. 16) Genetic segregation implies that the of the allele pair determining each trait are distributed to different gametes during mitosis. Answer: FALSE 20. 17) Genetic variation results from the crossing over and exchange of chromosomal parts that occur during meiosis II. Answer: FALSE 21. 18) Small RNAs control the timing of programmed cell death during development. Answer: TRUE 22. 19) It takes a major deviation in the epigenetic marks of a specific chromosome to result in a devastating human illness. Answer: FALSE