Title: The Reproductive System
Course: Question Banks

Q: Prokaryotic organisms usually reproduce asexually by ________.
- budding (Incorrect. Invertebrate marine animals commonly reproduce by forming a new individual from the outgrowth of a part of a cell or body region.)
- fragmentation (Incorrect. Fragmentation is asexual reproduction by breaking the body into two (or more) parts with subsequent regeneration. The individuals that result differ in size.)
- binary fission (Correct. Prokaryotes normally reproduce by splitting into two identical organisms.)
A: binary fission

Q: ________ usually reproduce asexually by fragmentation.
- Prokaryotes (Incorrect. Prokaryotes normally reproduce by splitting into two identical organisms.)
- Vertebrates (Incorrect. Vertebrates generally reproduce sexually but use parthenogenesis in limited cases of asexual reproduction.)
- Sea stars (Correct. Fragmentation is asexual reproduction by breaking the body into two (or more) parts with subsequent regeneration. The individuals that result differ in size.)
A: Sea stars

Q: The most common form of asexual reproduction among vertebrates is ________.
- budding (Incorrect. Invertebrate marine animals like corals and hydras commonly reproduce by forming a new individual from the outgrowth of a part of a cell or body region.)
- fragmentation (Incorrect. Fragmentation occurs in invertebrate animals, not vertebrates.)
- parthenogenesis (Correct. Certain reptiles, amphibians, and fish are able to reproduce through the development of an unfertilized egg into a complete individual.)
A: parthenogenesis

Q: Sexual reproduction usually involves the combination of ________.
- two organisms into a new individual (Incorrect. If this was true, each new generation would have twice the amount of DNA as the last.)
- different reproductive cells from the same organism (Incorrect. There are hermaphrodites that can self-fertilize but this is not a common approach in sexual reproduction.)
- haploid reproductive cells to a diploid organism (Correct. Usually reproductive cells contain half the genetic material that will then combine to a single organism with the correct diploid complement.)
A: haploid reproductive cells to a diploid organism

Q: Sexual reproduction produces ________.
- identical gene combinations (Incorrect. This is not the outcome of sexual reproduction.)
- changes in the genetic complement (Incorrect. While plants in particular are able to reproduce across species line, producing offspring with different amounts of genetic material than either parent, this is not the standard output of sexual reproduction.)
- unique gene combinations (Correct. This is believed to be the largest reason for sexual reproduction.)
A: unique gene combinations

Q: Self-fertilization is common in animals that ________.
- live in extreme environments (Incorrect. Extreme environments usually support fewer animals, but these are not often self-fertilizing hermaphrodites.)
- are invertebrates (Incorrect. Most hermaphroditic animals are invertebrates, but several of these still need a partner for reproduction.)
- have limited or no motility (Correct. Animals such as attached barnacles and clams often self-fertilize.)
A: have limited or no motility

Q: Mammals determine sex using ________.
- temperature differences during development (Incorrect. Environmental impacts, such as temperature changes, are used to determine sex in some crocodiles and turtles.)
- the number of X chromosomes present (Incorrect. A “dosage” effect based on the number of a sex chromosome is more common in insects like bees.)
- X and Y chromosomes (Correct. In mammals, the Y chromosome causes the development of male characteristics and reproductive cells.)
A: X and Y chromosomes

Q: The ZW system is used to determine sex in ________.
- crocodiles (Incorrect. Environmental impacts, such as temperature changes, are used to determine sex in some crocodiles and turtles.)
- insects (Incorrect. Some insects use an XY system, others a dosage effect based on one sex chromosome,and still others do use a ZX system.)
- avians (Correct. Birds use Z and W to determine sex: males are ZZ and females are ZW.)
A: avians

Q: Male birds are ________.
- heterozygous for sex chromosomes (Incorrect. Male mammals are XY.)
- protandry (Incorrect. Protandry is applied to organisms that begin life as males but later change sex.)
- homozygous for sex chromosomes (Correct. Male birds are ZZ.)
A: homozygous for sex chromosomes

Q: High levels of testosterone are produced by ________ once a male reaches adolescence.
- seminiferous tubules (Incorrect. This is the site of sperm maturation.)
- Sertoli cells (Incorrect. These cells serve as nursemaids that protect and promote development of the male germ cells.)
- cells of Leydig (Correct. These interstitial cells are mixed in the walls of the seminiferous tubules.)
A: cells of Leydig

Q: A vasectomy removes a section of the ________.
- epididymis (Incorrect. Sperm are still produced and mature after a vasectomy; this requires an intact epididymis.)
- bulbourethral gland (Incorrect. This gland does not conduct sperm from the male reproductive system.)
- vas deferens (Correct. This tube forms the ejaculatory duct that sperm normally travel to leave the body. Clipping it prevents sperm from being passed out of the body.)
A: vas deferens

Q: The ________ ensure that semen is alkaline, so sperm will be motile upon entering the vagina.
- prostate gland (Incorrect. This gland produces PSA, which helps to liquefy ejaculate.)
- bulbourethral gland (Incorrect. This gland releases a secretion prior to the bulk of the semen that neutralizes any acidic residues in the urethra.)
- seminal vesicles (Correct. These glands produce an alkaline solution that accounts for 60 percent of the bulk of semen.)
A: seminal vesicles

Q: The clitoris ________.
- protects the openings to the vagina and urethra (Incorrect. This is the labia minora.)
- functions in intercourse, childbirth, and during menstruation (Incorrect. This is the vagina.)
- is the main sensory organ of the female reproductive system (Correct. This erectile tissue contains a large number of sensory nerves.)
A: is the main sensory organ of the female reproductive system

Q: The developing fetus is supported in the ________.
- vagina (Incorrect. This tube functions in intercourse, childbirth, and during menstruation.)
- cervix (Incorrect. This is part of the uterus that functions as the birth canal.)
- uterus (Correct. This structure supports the developing embryo and fetus during gestation.)
A: uterus

Q: ________ in women is/are sealed by a tubal ligation.
- Ovaries (Incorrect. The ovaries remain “open” and functional after a tubal ligation.)
- The cervix (Incorrect. This is part of the uterus that functions as the birth canal. It is not impacted by a tubal ligation.)
- Oviducts (Correct. Severing and sealing the fallopian tubes prevents eggs from being fertilized.)
A: Oviducts

Q: Phase ________ of the sexual response in both men and women results in involuntary muscle contractions.
- two (Incorrect. During plateau, stimulation continues and breathing and heart rate increase.)
- four (Incorrect. During resolution, all physiological responses return to their normal state.)
- three (Correct. Orgasm is characterized by rhythmic, involuntary muscle contractions in both sexes.)
A: three

Q: What occurs during phase one of the sexual response in both men and women?
- involuntary muscle contractions (Incorrect. Orgasm is characterized by rhythmic, involuntary muscle contractions in both sexes, and occurs in phase three.)
- breathing and heart rate increase (Incorrect. During plateau, stimulation continues and breathing and heart rate increase.)
- visual clues of sexual arousal appear (Correct. During excitement, vasodilation leads to vasocongestion in erectile tissues and engorgement and enlargement of several structures such as the nipples.)
A: visual clues of sexual arousal appear

Q: During which phase does semen expel from the penis?
- two (Incorrect. During plateau, stimulation continues and breathing and heart rate increase.)
- four (Incorrect. During resolution, all physiological responses are returning to their normal state.)
- three (Correct. During orgasm, involuntary muscle contraction occurs and the urethra contracts expelling semen from the penis.)
A: three

Q: Gametogenesis requires the process of ________.
- mitosis (Incorrect. Mitosis is a process of cellular division that creates identical cells with the same amount of DNA as the parental cell.)
- crossing over (Incorrect. Crossing over occurs during gametogenesis and increases genetic variability, but it is not required.)
- meiosis (Correct. This type of cellular division results in cells with half the genetic complement of the parental cell. When two gametes fuse, the full complement is recreated.)
A: meiosis

Q: Spermatogonia ________.
- are active throughout a male’s life (Incorrect. These cells are inactive from birth through adolescence.)
- degrade during middle age (Incorrect. Male stem cells continue to produce viable sperm into old age.)
- produce viable sperm after adolescence (Correct. Puberty in males activates these stem cells, which have been in an arrested state since birth.)
A: produce viable sperm after adolescence

Q: ________ will give rise to a limited number of eggs during a woman’s life.
- Oocytes (Incorrect. Oocytes are eggs.)
- Ovaries (Incorrect. Ovaries do not give rise to eggs.)
- Oogonium (Correct. Unlike spermatogonia, oogonia do not divide into primary oocytes and more oogonia. Therefore a woman produces a limited number of eggs while a man can produce new sperm throughout his life.)
A: Oogonium

Q: ________ enters the male reproductive system and stimulates Sertoli cells for the first time at puberty.
- LH (Incorrect. This is not the role of LH in the male reproductive system.)
- GnRH (Incorrect. This is not the role of GnRH in the male reproductive system.)
- FSH (Correct. This is the role of FSH in the male reproductive system.)
A: FSH

Q: LH enters the male reproductive system and stimulates ________ for the first time at puberty.
- Sertoli cells (Incorrect. These cells are stimulated by FSH, not LH.)
- testes (Incorrect. Testes are not stimulated by LH, but house the cells that are.)
- interstitial cells of Leydig (Correct. These cells begin to make and release testosterone at this point.)
A: interstitial cells of Leydig

Q: The release of ________ will cause spermatogenesis to slow down.
- testosterone (Incorrect. Testosterone stimulates spermatogenesis.)
- GnRH (Incorrect. GnRH levels have a positive impact on spermatogenesis.)
- inhibin (Correct. These hormone is released when sperm count is too high, resulting in a decrease in the rate of sperm production.)
A: inhibin

Q: ________ is responsible for secondary sexual features in women.
- Testosterone (Incorrect. This causes secondary sexual features in men.)
- Progesterone (Incorrect. This hormone assists in endometrial regrowth and inhibition of FSH and LH release.)
- Estrogen (Correct. Estrogen promotes breast development, flaring of the hips, and shorter bone maturation.)
A: Estrogen

Q: Progesterone works to ________.
- guide the development of secondary sexual features (Incorrect. Estrogen promotes breast development, flaring of the hips, and shorter bone maturation. It also assists with endometrial regrowth but does not impact FSH and LH release.)
- guide the development of primary sexual features (Incorrect. Primary sexual features are genetically controlled in humans.)
- inhibit FSH and LH release (Correct. This hormone assists in endometrial regrowth and inhibition of FSH and LH release.)
A: inhibit FSH and LH release

Q: FSH stimulates ________.
- ovulation (Incorrect. LH stimulates induction of ovulation.)
- secondary sexual features (Incorrect. Estrogen stimulates secondary sexual features in females.)
- the development of eggs (Correct. Ova develop inside follicles after exposure to FSH.)
A: the development of eggs

Q: The process of ________ governs the release of eggs on a regular cycle.
- the menstrual cycle (Incorrect. The menstrual cycle prepares and maintains the uterine lining, which is required for implantation of a fertilized egg.)
- menopause (Incorrect. Menopause is the process by which the menstrual cycle ends and viable eggs are no longer released from the ovarian cycle.)
- the ovarian cycle (Correct. The hormonal rise and fall associated with the ovarian cycle actually prepares an egg for ovulation.)
A: the ovarian cycle

Q: Menstrual flow corresponds to a time of ________ levels during the menstrual cycle.
- high estradiol and progesterone (Incorrect. Both hormones do not have high levels during menstrual flow.)
- high estradiol and low progesterone (Incorrect. This combination occurs as the menstrual cycle moves from the proliferative to secretory phase.)
- low estradiol and progesterone (Correct. Both hormones are at their lowest levels during menstrual flow.)
A: low estradiol and progesterone

Q: After menopause, ________.
- a woman has exhausted her egg supply (Incorrect. Women still have eggs and potential follicles after menopause.)
- fertilized eggs will no longer implant properly in the uterus (Incorrect. After menopause viable eggs are not produced, so there is nothing to be fertilized.)
- ovaries no longer respond to FSH and LH (Correct. Insensitivity to these hormones causes the menstrual cycle to halt and prevents the ovaries from releasing viable eggs.)
A: ovaries no longer respond to FSH and LH

Q: ________ is the combination of an egg and a sperm.
- Union (Incorrect. This is not the term to describe the combination of a sperm and an egg.)
- Fusion (Incorrect. This is not the combination of an egg and a sperm.)
- Fertilization (Correct. This is the start of sexual reproduction.)
A: Fertilization

Q: Embryos formed from ________ are not viable and die within days.
- external fertilization (Incorrect. External fertilization is a common mechanism used in sexual reproduction.)
- acrosomal reactions (Incorrect. This is a normal part of fertilization: it is required for an embryo to form.)
- polyspermy (Correct. Fertilization of a single egg by multiple sperm will result in a non-viable embryo.)
A: polyspermy

Q: Most mammalian eggs are protected by the ________.
- cytoplasm (Incorrect. Eggs have cytoplasm but it does not serve a protective function.)
- acrosomes (Incorrect. The acrosome is found at the tip of sperm in placental mammals; it contains enzymes that allow the sperm to fuse with the egg.)
- zona pellucida (Correct. The zona pellucida is a layer of mainly glycoproteins that surrounds and protects the egg.)
A: zona pellucida

Q: External fertilization is common in ________.
- dry climates (Incorrect. Eggs released externally do not have protective shells, so would be damaged in dry environments.)
- humid landscapes (Incorrect. External fertilization is not associated with land.)
- aquatic environments (Correct. Both eggs and sperm are released into the environment for external fertilization. The watery environment keeps the eggs from drying out, since it must be “bare.”)
A: aquatic environments

Q: The survival rate of eggs in broadcast spawning is ________.
- relatively high (Incorrect. This is an inefficient method of fertilization and reproduction.)
- about average (Incorrect. This is an inefficient method of fertilization and reproduction.)
- quite low (Correct. Millions of eggs must be produced for broadcast spawning; the overall survival rate is low.)
A: quite low

Q: Nearly all fish reproduce by ________.
- ovoviparity (Incorrect. Few fish use internal fertilization methods.)
- viviparity (Incorrect. Few fish use internal fertilization methods.)
- spawning (Correct. Spawning in common in fish, crustaceans, mollusks, squid, and echinoderms.)
A: spawning

Q: In ________, fertilized eggs are laid outside the female’s body.
- viviparity (Incorrect. This is internal development of young within the female body.)
- ovoviparity (Incorrect. In this case, fertilized eggs remain inside the female’s body but they are nourished by the egg’s yolk, not the female.)
- oviparity (Correct. In this case, the developing young are nourished by the egg’s yolk and hatch fully formed.)
A: oviparity

Q: Only limited groups of animals reproduce by ________.
- viviparity (Incorrect. This is internal development of young within the female body, which is how most mammals reproduce.)
- oviparity (Incorrect. In this case, the developing young are nourished by the egg’s yolk and hatch fully formed. This is common in fish, reptiles, and is the only method used by birds.)
- ovoviparity (Correct. This type of development is found in members of larger groups, such as some sharks and some lizards, but is not utilized by any entire group of animals.)
A: ovoviparity

Q: In ________ reproduction, a placenta is required for nutrient exchange.
- ovoviparity (Incorrect. There are no mammals that utilize ovoviparity: it is common in some reptiles and invertebrates.)
- oviparity (Incorrect. In this case, the developing young are nourished by the egg’s yolk and hatch fully formed. This is common in fish, reptiles, and is the only method used by birds.)
- viviparity (Correct. This is internal development of young within the female body, which is how most mammals reproduce.)
A: viviparity

Q: Complete reproductive systems first developed in ________.
- annelids (Incorrect. Annelids display an early form of reproduction in which there were not separate sexes.)
- mammals (Incorrect. Complete reproductive systems developed before mammals.)
- insects (Correct. Insects have separate sexes with complete reproductive systems and organs.)
A: insects

Q: A ________ is a common body opening for the digestive, excretory, and reproductive systems.
- vulva (Incorrect. A vulva is a body opening for the reproductive system.)
- urethra (Incorrect. A urethra is an opening for the excretory system, though in male placental mammals, it also conducts material from the reproductive system.)
- cloaca (Correct. This type of opening is found in birds and reptiles.)
A: cloaca

Q: Mammals that produce large numbers of offspring at one time have a ________ uterus.
- multi-lobed (Incorrect. There is no multi-lobed uterus.)
- one-chambered (Incorrect. Mammals that produce (usually) one offspring at a time have a uterus with a single chamber. The occasional multiple birth such as twins or triples does not change this.)
- two-chambered (Correct. There are two chambers in the uterus of mammals that produce litters.)
A: two-chambered

Q: The ________ stage occurs after the zygote has cleaved into a 100 cell sphere.
- blastocoel (Incorrect. This is the fluid-filled cavity at the center of the cellular sphere.)
- blastocyst (Incorrect. The blastocyst is the next stage of development in mammals.)
- blastula (Correct. After fertilization occurs, the zygote is formed. This single cell then divides to produce the hollow blastula.)
A: blastula

Q: ________ is cell division in a zygote but with no change in overall size.
- Meiosis (Incorrect. This is the process of cell division that generates haploid cells from diploid cells.)
- Mitosis (Incorrect. Mitosis yields cells the same size as the parent, so the overall size of the zygote would increase.)
- Cleavage (Correct. During cleavage the zygote cell divides repeated but never grows, so each cycle results in smaller cells.)
A: Cleavage

Q: Placental mammals undergo ________ cleavage.
- meroblastic (Incorrect. Meroblastic cleavage occurs in animals nourished by egg yolk, not by the mother.)
- incomplete (Incorrect. There is no “incomplete” cleavage, only complete and partial.)
- holoblastic (Correct. Because the zygote and fetus are nourished by the mother, placental mammals can undergo complete cleavage during early development.)
A: holoblastic

Q: The process of ________ results in the formation of three distinct germ layers.
- blastulation (Incorrect. Cleavage results in a blastula; sometimes this is called blastulation.)
- embryogenesis (Incorrect. This is simply the formation of the embryo.)
- gastrulation (Correct. Gastrulation gives rise to the three germ layers needed to establish a body plan.)
A: gastrulation

Q: The ________ gives rise to the nervous system.
- endoderm (Incorrect. This germ layer gives rise to the columnar cells of the digestive system and many internal organs.)
- mesoderm (Incorrect. This layer gives rise to the muscle cells and connective tissues of the body.)
- ectoderm (Correct. This germ layer generates the nervous system and epidermis.)
A: ectoderm

Q: Red blood cells are generated by the ________ layer.
- endoderm (Incorrect. This germ layer gives rise to the columnar cells of the digestive system and many internal organs.)
- ectoderm (Incorrect. This germ layer generates the nervous system and epidermis.)
- mesoderm (Correct. This layer gives rise to the muscle cells and connective tissues of the body.)
A: mesoderm

Q: During organogenesis, ________ organ development.
- differences in the direction of cell division influence (Incorrect. This is not how different organs develop.)
- gravity impacts (Incorrect. This is not how different cell types arise.)
- gene expression patterns control (Correct. It is through differences in which genes are expressed that different cell types arise.)
A: gene expression patterns control

Q: A key event in vertebrate organogenesis is formation of the ________.
- epidermis (Incorrect. Epidermis forms in many animals.)
- reproductive system (Incorrect. All organisms need some type of reproductive system.)
- neural tube (Correct. The neural tube gives rise to the neural system: the brain and spinal cord.)
A: neural tube

Q: ________ give rise to ribs, lungs, and segmental muscles.
- Somatic cells (Incorrect. Somatic cells just means body cells; this is technically correct but not the answer here.)
- Notochord (Incorrect. The notochord gives rise to the central axis of the body.)
- Somites (Correct. These cells arise from mesoderm cells with a spatial pattern of gene expression.)
A: Somites

Q: Vertebrate axes are formed as a result of ________.
- differences in the direction of cell division (Incorrect. This is not how vertebrate axes develop.)
- gravity impacts (Incorrect. This is not how vertebrate axes develop.)
- specific gene expression (Correct. Vertebrate axes are established following expression of specific genes.)
A: specific gene expression

Q: Animals have ________ symmetry.
- internal (Incorrect. Animals are not internally symmetric.)
- internal and external (Incorrect. Animals are not internally symmetric.)
- external (Correct. Animals have externally visible symmetry.)
A: external

Q: The head-feet axis is the ________ axis.
- lateral-medial (Incorrect. This is the left-right axis.)
- dorsal-ventral (Incorrect. This is the back-belly axis.)
- anterior-posterior (Correct. This is the axis that distinguishes the head and feet.)
A: anterior-posterior

Q: A human embryo must implant within ________.
- twenty-four hours (Incorrect. An egg becomes a mature oocyte twenty-four hours before fertilization.)
- five days (Incorrect. An embryo is at the blastocyst stage five days after fertilization.)
- seven days (Correct. An embryo must implant within seven days or it will deteriorate and die.)
A: seven days

Q: Internal organs begin to develop during the ________ trimester.
- second (Incorrect. This is not when organ development begins.)
- third (Incorrect. During third trimester rapid growth occurs but organs have already begun to develop.)
- first (Correct. Internal organs and body structures begin to develop in the first trimester; the body is essentially formed by eight weeks.)
A: first

Q: The baby is expelled from the uterus during stage ________ of labor.
- one (Incorrect. This is when the cervix thins and dilates in preparation for delivery.)
- three (Incorrect. The placenta disengages from the uterine wall and is expelled during stage three.)
- two (Correct. The baby is expelled during the process of delivery in stage two.)
A: two

Q: ________ is required to start and maintain labor, as well as release milk from mammary glands.
- Prolactin (Incorrect. Prolactin is required to produce milk, but not to release it.)
- Prostaglandins (Incorrect. These hormones increase contractions in the uterine wall.)
- Oxytocin (Correct. Oxytocin causes the initial contractions of the uterine walls, and triggers milk to release from mammary glands.)
A: Oxytocin

Q: A baby suckling at the breast triggers release of prolactin from the ________.
- posterior pituitary (Incorrect. Oxytocin is released from the posterior pituitary gland.)
- hypothalamus (Incorrect. Signals from the hypothalamus trigger release of prolactin, but the hypothalamus itself does not release prolactin.)
- anterior pituitary (Correct. Prolactin is released from the anterior pituitary gland.)
A: anterior pituitary

Q: The highest failure rate occurs in the ________ method of contraception.
- barrier (Incorrect. Barrier methods fail 15–24 percent of the time, making them second or third in failure rates.)
- natural family planning (Incorrect. Natural family planning methods fail 12–25 percent of the time, making them second or third in failure rates.)
- withdrawal (Correct. Over the course of 12 months, withdrawal will fail to prevent conception 27 percent of the time.)
A: withdrawal

Q: The most successful form of contraception is ________.
- natural family planning (Incorrect. Natural family planning methods fail 12–25 percent of the time, making them second or third in failure rates.)
- hormonal patches (Incorrect. Hormonal patches, rings, and oral medications fail 8 percent of the time.)
- sterilization (Correct. Sterilization and hormonal implants both have better than 99 percent success rate in preventing conception over 12 months.)
A: sterilization

Q: Hormonal contraceptive measures ________.
- prevent successful fertilization (Incorrect. Hormonal contraceptives do not interfere with the actual process of fertilization.)
- prevent implantation (Incorrect. The “morning after” pill can prevent implantation but this is not a standard hormonal contraceptive.)
- inhibit release of FSH or LH (Correct. Inhibiting these two hormones prevent an egg from being released for fertilization.)
A: inhibit release of FSH or LH

Q: Around ________ of the causes of infertility can be identified.
- 25 percent (Incorrect. This percentage is too low: many more causes of infertility can be identified.)
- 50 percent (Incorrect. This is not the correct percentage.)
- 75 percent (Correct. The majority of the causes of infertility can be identified.)
A: 75 percent

Q: ________ involves physically injecting a sperm into an egg.
- ART (Incorrect. Not all assisted reproductive technologies involve physically injecting sperm into the egg.)
- IVF (Incorrect. In vitro fertilization simply involves combining an egg and sperm outside the body.)
- ICSI (Correct. Intracytoplasmic sperm injection injects the sperm into an egg.)
A: ICSI

Q: Implantation occurs ________ following IVF.
- immediately after fertilization (Incorrect. Implantation does not occur this soon after a round of IVF.)
- after the gastrulation stage (Incorrect. Implantation must occur by the blastula stage or the body will not be prepared to support the developing zygote.)
- after the 8-cell stage (Correct. Embryos are supported through several rounds of cell division to ensure viability before implantation after IVF.)
A: after the 8-cell stage