Quiz 29: Development, Growth, Aging, and Genetics

The period from conception until birth is A) the prenatal period. B) the germinal period. C) the embryonic period. D) the fetal period. E) the conceptual period.

The prenatal period during which the major organ systems form is the A) fetal period. B) germinal period. C) embryonic period. D) neonatal period.

What event separates childhood from adolescence? A) puberty B) infancy C) formation of germ layers D) beginning to walk

Germ layers form during the ____ period while organ systems mature during the ____ period. A) embryonic; fetal B) prenatal; neonatal C) germinal; embryonic D) germinal; fetal E) fetal; germinal

The clinical age of the unborn child is calculated from A) ovulation. B) conception. C) the last menstrual period. D) fourteen days after the last menstrual period. E) fourteen days before the last menstrual period.

Developmental events are calculated from A) ovulation. B) conception. C) the last menstrual period. D) fourteen days after the last menstrual period. E) fourteen days before the last menstrual period.

Fusion of the male and female pronuclei A) results in an oocyte forming. B) restores the diploid number of chromosomes. C) occurs before ovulation. D) results in a haploid cell forming. E) results in a total of 23 chromosomes.

Depolarization of the oocyte plasma membrane occurs when the first sperm attaches to the integrin 61. This is called the A) slow block to polyspermy. B) acrosomal reaction. C) fast block to polyspermy. D) fertilization. E) spermiogenesis.

Fusion of the male and female pronuclei forms the A) blastocyst. B) morula. C) zygote. D) gastrula. E) trophoblast.

If the zygote splits into two separate cells, A) identical twins result. B) fraternal twins result. C) dizygotic twinning occurs. D) both cells die. E) paternal twins result.

If a woman ovulates two oocytes and both are fertilized, A) identical twins result. B) fraternal twins result. C) Siamese twins result. D) monozygotic twinning occurs. E) paternal twins result.

An embryonic cell that has the potential to develop into a wide range of tissues is called a/an A) differentiated cell. B) multipotent cell. C) pluripotent cell. D) omnipotent cell. E) totipotent cell.

An embryonic cell that contains the potential to give rise to any tissue type is called a/an A) differentiated cell. B) multipotent cell. C) pluripotent cell. D) omnipotent cell. E) totipotent cell.

Once the embryonic mass has 12 or more cells, it is called a A) morula. B) gastrula. C) blastula. D) blastocyst. E) trophoblast.

The single layer of cells that surrounds the blastocele is the A) morula. B) gastrula. C) blastocyst. D) trophoblast. E) inner cell mass.

When the embryonic mass of cells develops an internal cavity, the mass of cells is called a(n) A) zygote. B) morula. C) blastocyst. D) embryonic disc. E) trophoblast.

The inner cell mass of the blastocyst A) consists of yolk-filled storage cells. B) contains cells that will form the embryo. C) represents the future placenta. D) will form the zona pellucida. E) contains cells that are discarded.

The placenta and membranes surrounding the embryo develop from the A) morula. B) blastocyst. C) trophoblast. D) inner cell mass. E) blastocele.

At the time of implantation, the human embryo is in a stage of development known as the A) fetus. B) zygote. C) morula. D) blastocyst. E) egg.

The placenta plays an important role in A) implantation. B) onset of lactation. C) beginning of parturition. D) provision of nutrients to the fetus. E) insulating the fetus.

The time period between fertilization and implantation is approximately A) 5 days. B) 7 days. C) 10 days. D) 14 days. E) 21 days.

Which of the following statements about the syncytiotrophoblast is false? A) It forms the developing embryo. B) It is composed of a non-dividing, multinucleated cell. C) It is nonantigenic, so that it triggers no immune response. D) It invades the maternal tissues that compose the endometrium of the uterus. E) It forms lacunae.

The cytotrophoblast A) forms the chorionic villi. B) replaces the syncytiotrophoblast. C) remains throughout development. D) forms branches that protrude into the amniotic cavity. E) is not an embryonic part of the placenta.

The chorionic villi A) form from branches of the syncytiotrophoblast cords. B) increase surface area of the amniotic cavity. C) contribute to the formation of the placenta. D) are necessary for implantation to occur. E) are not part of the placental formation.

Placenta previa occurs when A) a normally placed placenta tears away from the uterine wall. B) the placenta is formed too early. C) implantation occurs close to the cervix. D) implantation occurs in the fundus of the uterus.

Where does implantation normally occur? A) in the fundus area of the uterus B) in the isthmus area of the uterine tube C) in the cervix area of the uterus D) in the infundibulum area of the uterine tube

The embryonic disk is initially composed of A) ectoderm and hypoblast. B) epiblast and mesoderm. C) epiblast and hypoblast. D) hypoblast and yolk sac. E) epiblast and yolk sac.

The embryonic membrane that completely encloses the embryo in a watery sac is the A) yolk sac. B) amnion. C) allantois. D) chorion. E) ectodermal sac.

Gastrulation is the process of development that produces the A) placenta. B) embryonic disk. C) germ layers. D) rudimentary organs.

Some epiblast cells migrate and emerge between the epiblast and endoderm as a new germ layer called the A) yolk sac. B) mesoglia. C) notochord. D) mesoderm. E) primitive streak.

Through what structure do epiblast cells migrate to form the mesoderm? A) lacunae B) chorionic villi C) hypoblast D) primitive streak E) blastocele

Which of the following is derived from ectoderm? A) lens of the eye B) thymus gland C) tonsils D) urinary bladder E) dermis of skin

Which of the following is derived from endoderm? A) brain B) muscle C) epidermis of the skin D) lining of the digestive tract E) cardiovascular system

Which of the following is formed from mesoderm? A) autonomic neurons B) dermis of the skin C) adrenal medulla D) teeth E) tonsils

Damage to the mesoderm during embryological development would affect the formation of the A) thyroid. B) brain. C) heart. D) teeth. E) urinary bladder.

Which of the following organ systems is derived from all three germ layers? A) nervous B) cardiovascular C) endocrine D) integumentary E) skeletal

Which germ layer is most muscle derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer is the thymus derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer is the thyroid derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer is the epidermis derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer is tooth enamel derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer is the cardiovascular system derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer is the urinary bladder derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer is the brain and spinal cord derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer are the bones (except facial) derived from? A) ectoderm B) mesoderm C) endoderm

Which germ layer are the tonsils derived from? A) ectoderm B) mesoderm C) endoderm

Arrange the following in the sequence in which they form in the embryo. (1) neural plate (2) neural tube (3) notochord (4) primitive streak A) 1, 2, 3, 4 B) 1, 3, 2, 4 C) 4, 3, 1, 2 D) 4, 1, 3, 2 E) 3, 4, 1, 2

The embryo is most sensitive to outside influences that can cause malformations during the A) first two weeks after fertilization. B) third to the ninth weeks of development. C) ninth to the sixteenth weeks of development. D) twelfth to the twentieth weeks of development. E) twenty-first to twenty-sixth week of development.

Which of the following is NOT a possible route for neural crest cells? A) melanocytes B) autonomic ganglion neurons C) adrenal cortex D) sensory ganglia E) enteric nervous system neurons

Cells of the neuroectoderm become all of the following EXCEPT the A) brain B) spinal cord C) postganglionic autonomic neurons D) posterior pituitary gland

Somites give rise to A) nerves. B) blood. C) glands. D) muscles. E) spinal cord.

Segments of mesoderm that will form muscles are A) mesonephros. B) mandibular processes. C) neural tube. D) secondary palate. E) somites.

The oropharyngeal and cloacal membranes, when opened, allow the _____ to open to the outside. A) liver B) skin C) lungs D) digestive tract E) ears

Which of the following organs develops from evaginations along the early digestive tract? A) heart B) adrenal medulla C) lungs D) nasal cavity E) kidneys

The pleural and peritoneal cavities of the adult begin as part of the _____ cavity. A) cloacal B) somatomeric C) coelomic D) apical E) ventral

The allantois enlarges to form the A) kidney. B) gonads. C) ureter. D) urinary bladder. E) urethra.

Arm and legs buds appear at about 28 days from A) the coelom. B) apical ectodermal ridges. C) somitomeres. D) neural crest cells.

A cleft lip results when A) the two halves of the secondary palate do not fuse. B) the frontonasal and maxillary processes do not fuse. C) the lateral edges of the nasal placodes do not fuse with the maxillary processes. D) the maxillary processes do not fuse with the mandibular processes. E) None of these choices is correct.

If the secondary palate does not fuse the result is a A) cleft palate. B) cleft throat. C) facial cleft. D) cleft lip. E) cleft tongue.

Which of the following structures is NOT involved in the formation of the face? A) apical ectodermal ridges B) frontonasal process C) maxillary processes D) mandibular processes

What structure forms the lower jaw? A) mesonephros B) mandibular processes C) neural tube D) secondary palate E) somites

What structure forms the roof of the mouth? A) mesonephros B) mandibular processes C) neural tube D) secondary palate E) somites

Organogenesis is generally completed by day _____ of development. A) 20 B) 30 C) 45 D) 60 E) 75

Which of the following statements concerning development of the integumentary system is true? A) The epidermis is derived from mesoderm. B) The melanocytes are derived from ectoderm. C) Nails, hair, and glands develop from the dermis. D) Sensory receptors in the skin are derived from the epidermis. E) Collagen fibers do not appear until after birth.

Which of the following statements concerning musculoskeletal system development is true? A) Skeletal muscles develop from crest cells. B) Myoblasts produce somites. C) The vertebral column develops from somite-derived mesoderm. D) Enlargement of muscles after birth is due to an increase in the number of muscle fibers. E) Ossification ends before birth.

Failure of the neural tube to close in the region of the head results in A) anencephaly. B) ventricular enlargement. C) cleft palate. D) soft spots on the skull. E) hydrocephaly.

The central cavity of the neural tube becomes the A) cerebrum. B) mid-brain. C) cranial cavity. D) ventricles of the brain. E) epidural space.

What is formed by closure of neural groove? A) mesonephros B) mandibular processes C) neural tube D) secondary palate E) somites

The eyes develop as an evagination from the A) myelencephalon. B) mesencephalon. C) neural crest cells. D) diencephalon. E) telencephalon.

The olfactory bulbs and nerves develop as an evagination from the A) myelencephalon. B) mesencephalon. C) neural crest cells. D) diencephalon. E) telencephalon.

Which of the following structures originates as an evagination from the floor of the pharynx, moves into the neck, and loses its connection with the pharynx? A) pancreas B) thyroid gland C) adrenal medulla D) adenohypophysis E) parathyroid glands

Which gland is formed by an evagination from the floor of the diencephalon? A) anterior pituitary gland B) posterior pituitary gland C) thyroid gland D) adrenal glands E) pancreas

Which gland is derived from both neural crest cells and mesoderm? A) anterior pituitary gland B) posterior pituitary gland C) thyroid gland D) adrenal glands E) pancreas

Which gland originates as two evaginations from the duodenum? A) anterior pituitary gland B) posterior pituitary gland C) thyroid gland D) adrenal glands E) pancreas

Which gland develops from an evagination of the ectoderm in the roof of the embryonic oral cavity? A) anterior pituitary gland B) posterior pituitary gland C) thyroid gland D) adrenal glands E) pancreas

The embryonic heart A) develops from two endothelial tubes that fuse together. B) consists of four chambers. C) has two atria but only one ventricle. D) doesn't beat until just prior to birth. E) has no passages connecting right side to left side.

The opening that connects the right and left atria in the fetal heart is the A) interatrial septum. B) septum primum. C) septum secundum. D) foramen ovale. E) foramen rotundum.

Which of the following statements concerning the embryonic circulatory system is true? A) The heart develops from four endothelial tubes. B) Blood vessels form from blood islands. C) An opening in the interatrial septum is called the sinus venosus. D) The bulbus cordis becomes the sinoatrial node (the adult pacemaker). E) There is an opening in the interventricular septum.

The lungs develop from A) somitomeres. B) neural crest cells. C) an evagination from the foregut. D) an evagination from the floor of the diencephalon. E) an invagination from the hindgut.

The adult kidney develops from the A) pronephros. B) metanephros. C) mesonephros. D) allantois. E) neonephros.

The common junction of the digestive, urinary, and genital systems is the A) cloaca. B) coelom. C) allantois. D) hindgut. E) anus.

Which of the following sequences is correct? A) mesonephros, pronephros, metanephros B) metanephros, pronephros, mesonephros C) pronephros, mesonephros, metanephros D) pronephros, metanephros, mesonephros E) mesonephros, metanephros, pronephros

The first functional kidney is the A) mesonephros. B) pronephros. C) allantois. D) bulbos cordis. E) urorectal septum.

The gonads appear as the A) paramesonephrons. B) urogenital folds. C) labioscrotal swellings. D) gonadal ridges. E) gonadal grooves.

Cryptorchidism A) is the failure of the testes to descend into the scrotal sac. B) may be due to excessive amounts of testosterone in the fetus. C) has no effect on fertility. D) results in feminization of the male fetus. E) is the lack of testes.

If neither testosterone nor mullerian-inhibiting hormone is secreted during embryonic development A) the paramesonephric duct system degenerates. B) the mesonephric duct system is stimulated. C) internally female reproductive structures form. D) the individual appears as a male. E) internally male reproductive structures form.

The male and female reproductive systems begin as an indifferent stage. If testosterone is present, which of the following occurs? A) The paramesonephric duct forms the vagina. B) The mesonephric ducts form the ductus deferens. C) The mesonephric ducts atrophy. D) The paramesonephric ducts enlarge to form the scrotum. E) The paramesonephric duct atrophies.

In females, the genital tubercle becomes the A) uterus. B) ovary. C) clitoris. D) vagina. E) labia.

In males, the urogenital folds close over the urogenital opening and urethral groove to form the A) scrotum. B) testes. C) vas deferens. D) penis. E) prostate gland.

The testes leave the abdominal cavity and reach the scrotum by passing through the A) urogenital opening. B) inguinal canal. C) cloaca. D) urethra. E) Wolffian ducts.

An embryo becomes a fetus about A) 14 days after fertilization. B) 30 days after fertilization. C) 60 days after fertilization. D) 3 months after fertilization. E) 6 months after fertilization.

The major difference between an embryo and a fetus is that A) a fetus can survive outside the mother's womb but an embryo cannot. B) a fetus is smaller than an embryo. C) organ systems are developing in an embryo while all organs are present in a fetus. D) a fetus is a male child while an embryo is a female child. E) None of these choices is correct.

Fine, soft hair that covers the fetus is called A) lanugo. B) fetal hair. C) colostrum. D) vernix caseosa. E) primary hair.

The waxy coat of sloughed epithelial cells that covers the fetus is called A) lanugo. B) fetal hair. C) colostrum. D) vernix caseosa. E) primary hair.

The type of fetal monitoring that uses sound waves to visualize the developing fetus is A) fetoscopy. B) ultrasound. C) amniocentesis. D) chorionic villi sampling. E) auscultation.

An infant born with a gestational age of 254 days would be considered A) premature. B) normal maturity. C) postmature. D) immature. E) None of these choices is correct.

One of the major problems a premature infant may develop is respiratory distress syndrome. This occurs because in a premature infant A) oxygen transport is impaired. B) surfactant isn't produced. C) the lungs are collapsed. D) there aren't enough red blood cells to carry oxygen. E) there is mixing of the arterial and venous blood.

The birth process is called A) micturition. B) gastrulation. C) organogenesis. D) parturition. E) expulsion.

The stage of labor in which the fetus is expelled is A) the first stage. B) the second stage. C) the third stage. D) the fourth stage. E) the fifth stage.

Which of the following events near the end of pregnancy might indicate parturition is near? A) The cervix gradually constricts. B) The uterus begins regular contractions. C) The amniotic sac becomes edematous. D) The fetal heart rate increases to greater than 160 beats per minute. E) The cervix shrinks.

Which of the following is correctly matched? A) first stage of labor - baby exits vagina B) second stage of labor - ends with cervix dilation to maximum C) third stage of labor - placenta expelled from uterus

Before parturition, A) the placenta secretes increased amounts of oxytocin. B) the uterus stretches, causing the release of ACTH from the adenohypophysis. C) there is an increase in the stimulatory effects of progesterone on the uterine muscle. D) prostaglandin synthesis is inhibited. E) fetal glucocorticoids decrease the production of progesterone by the placenta.

Onset of labor may result from A) increased estrogen secretion by the placenta. B) increased glucocorticoid secretion by the mother. C) increased secretion of oxytocin by the fetus. D) increased progesterone secretion by the placenta. E) decreased prostaglandins.

Which of the following conditions might result in stress on a fetus that has nearly completed 9 months of fetal development? A) placental growth greater than fetal growth B) cramped quarters in the uterus C) increased O₂ supply to the fetus D) excessive weight gain by the mother E) hormone fluctuations

Which of the following will cause contractions of uterine smooth muscle? A) increasing levels of progesterone B) decreasing levels of estrogen C) decreasing levels of oxytocin D) decreasing uterine stretch E) increasing levels of oxytocin

When stretch receptors in the cervix are stimulated by the continually increasing pressure of the fetus, afferent neurons send impulses to the maternal hypothalamus resulting in A) increased estrogen production. B) increased oxytocin production. C) increased fetal CRH production. D) increased growth in the size of the placenta. E) decreased oxytocin production.

Which of the following fetal shunts connects the umbilical vein with the inferior vena cava? A) ductus arteriosus B) umbilical vein C) umbilical artery D) ductus venosus E) foramen ovale

In fetal circulation, the blood containing the highest amount of oxygen is found in the A) aorta. B) umbilical vein. C) ductus arteriosus. D) umbilical arteries. E) heart.

Which of the following fetal shunts bypasses the fetal lungs? A) ductus arteriosus B) ductus venosus C) umbilical arteries D) umbilical vein E) ductus byosus

The closed foramen ovale becomes the _____ after birth. A) fossa ovalis B) ligamentum ovale C) ligamentum venosum D) ligamentum arteriosum E) valves

Which of the following is mismatched? A) foramen ovale - ligamentum ovale B) ductus arteriosus - ligamentum arteriosus C) ductus venosus - ligamentum venosus D) umbilical vein - ligamentum teres of the liver E) umbilical arteries - cords of umbilical arteries

A patent ductus arteriosus means that the _____ did not close. A) intraatrial septum B) intraventricular septum C) connection between the pulmonary trunk and the aorta D) connection between the inferior vena cava and the abdominal aorta E) umbilical arteries and veins

Which of the following statements concerning the digestive system of a newborn is true? A) The infant may lose 15% to 20% of his body weight in the first week. B) The pH of the stomach is nearly neutral, but increases in acidity after birth. C) The liver of the newborn is functionally mature. D) The ability to digest lactose does not occur until 48 hours after birth. E) All foods can be digested at birth.

The greenish discharge from the lower digestive tract shortly after birth is called A) colostrum. B) jaundice. C) bile. D) meconium. E) prolactin.

An APGAR score of _____ is considered normal at 1 to 5 minutes after birth. A) 2 B) 5 C) 9 D) 12 E) 25

APGAR scores are used to A) evaluate a newborn's weight. B) assess a newborn's physiological condition. C) measure a newborn's genetic state. D) determine the developmental age of the infant. E) measure the infant.

Most congenital birth defects are caused by A) inherited traits. B) lack of oxygen to the fetus. C) viral infections during pregnancy. D) unknown causes. E) None of these choices is correct.

Alcohol ingestion by a pregnant woman can cause birth defects in her baby; alcohol is a(an) A) carcinogen. B) mutagen. C) teratogen. D) oncogene. E) haptogen.

The hormone(s) responsible for preparing the breasts for lactation during pregnancy is (are). A) estrogen. B) progesterone. C) oxytocin. D) prolactin. E) both estrogen and progesterone.

The hormone responsible for milk production is A) estrogen. B) progesterone. C) oxytocin. D) prolactin. E) FSH.

Which of the following is involved in stimulating milk letdown? A) increased estrogen levels B) increased progesterone levels C) mechanical stimulation of the breasts that cause release of oxytocin D) secretion of a small amount of milk E) None of these choices is correct

Colostrum differs from milk in that it contains A) little fat. B) no antibodies. C) more protein. D) more lactose. E) more fat.

An infant who has just started cooing and gurgling in response to smiles and attention from its parents is about _____ months old. A) two B) four C) six D) eight E) ten

Which of the following characterizes the developmental age of an eight month old infant? A) sits without support B) rolls from its back to its side C) smiles in response to people's faces D) pulls itself up to a standing position E) None of these choices is correct

Neonate is the term used to refer to a baby A) in the 24-48 hours preceding birth. B) in the 24-48 hours after birth. C) during the first month after birth. D) during the six months after birth. E) during the first year after birth.

The earliest period of prenatal development is the _________ period. A) embryonic B) neonatal C) germinal D) infant E) fetal

The onset of puberty is considered to be the beginning of which life stage? A) early childhood B) late childhood C) adolescence D) young adult E) middle age

Many of the emotional characteristics of a person are formed during A) infancy. B) early childhood. C) adolescence. D) adulthood. E) neonatal period.

The onset of puberty is signaled by A) a growth spurt. B) emotional upheaval. C) attainment of full adult stature. D) the ability to obtain a drivers license. E) a halt to growth.

Puberty in females occurs _____ than in males. A) earlier B) later C) at the same time

Muscle strength peaks in a(n) A) child. B) adolescent. C) young adult. D) middle aged adult. E) elderly adult.

Which of the following is NOT a change associated with aging? A) loss of neurons B) loss of skeletal and cardiac muscle tissue C) decreased cross-linking of collagen D) decreased ability of the lens in the eye to accommodate E) arteriosclerosis

A clot or plaque which forms on the inside of blood vessel walls is called a(an) A) sclerosis. B) arteriosus. C) thrombus. D) embolus. E) plaque.

Increased lipid deposits in the tunica intima of large arteries is called A) atherosclerosis. B) arteriosclerosis. C) a thrombus. D) an embolus. E) hardening of the arteries.

Decreased renal filtration that occurs with aging can be the result of A) increased respiratory effort. B) decreased cardiac output. C) increased fluid volume. D) decreased ADH secretion. E) decreased peripheral resistance.

Premature aging is called A) progeria. B) lactation. C) parturition. D) Alzheimer's disease. E) dementia.

Which of the following vitamins are thought to play a role in decreasing the physiological changes in aging? A) vitamins A and B12 B) vitamins A and B6 C) vitamins E and C D) vitamins A and D E) vitamins A and K

Many gerontologists refer to walking as one of the most important anti-aging activities to prolong life. This is because a daily 30-minute walk A) increases blood pressure. B) improves circulation. C) promotes anaerobic metabolism. D) increases urine output. E) increases peripheral resistance.

Autoimmune diseases such as arthritis become more common as people get older. "Autoimmune" means that the immune system A) no longer produces antibodies. B) destroys the body's own tissues. C) is incapable of initiating phagocytosis. D) produces T cells but no B cells. E) protects itself.

One reason for the increased incidence of cancer with aging is a decrease in A) urine output. B) cardiac output. C) red blood cells. D) functioning of T lymphocytes. E) functioning neutrophils.

One component of brain death is defined as A) loss of reflexes. B) lack of spontaneous movement. C) a flat electroencephalogram (EEG).

The genotype WW is best described as A) homozygous recessive. B) homozygous dominant. C) heterozygous dominant. D) heterozygous recessive. E) homorecessive.

An organism's genetic makeup is its ____ while its physical appearance is its ____. A) chromotype; phenotype B) genotype; phenotype C) phenotype; genotype D) genotype; chromotype E) aminotype; prototype

In humans, somatic cells have ____ chromosomes, while reproductive cells (gametes) have ____. A) 23; 46 B) 92; 46 C) 46; 23 D) 46; 69 E) 92; 23

Which of the following genotypes will result in a male? A) XO B) XY C) XX D) XXX E) YY

A display of the chromosomes of a somatic cell during metaphase of mitosis is the A) karyotype. B) autosome. C) homolog. D) locus. E) genome.

The specific location of a gene on a chromosome is its A) homolog. B) genotype. C) phenotype. D) allele. E) locus.

Chromosome pairs are called A) karyotypes. B) genomes. C) homologous pairs. D) loci. E) haploid.

A gene that is responsible for producing trypsin in the pancreas would be a ____ gene. A) dominant B) regulatory C) structural D) recessive E) functional

A different form of an allele at a particular locus that can have no effect to major effects on the phenotype is a(n) A) allelic variant. B) mutated allele. C) polymorphism. D) All of the choices are correct.

When the dominant allele does not completely mask the effects of the recessive allele in the heterozygote, it is called A) dominance. B) polygenic dominance. C) codominance. D) incomplete dominance. E) corecessive.

What type of gene expression are the ABO blood types an example of? A) complete dominance B) codominance C) incomplete dominance D) recessiveness E) polymorphism

Which of the following is an example of incomplete dominance? A) minor thalassemia B) major thalassemia C) beta thalassemia D) polymorphism E) ABO blood groups

A person's height, intelligence, eye color, and skin color are examples of A) incomplete dominance. B) complete dominance. C) complete recessiveness. D) codominance. E) polygenic traits.

Genes on the X chromosomes are A) polygenic. B) X-linked. C) simple. D) holandric. E) Y-linked.

If an albino (aa) mates with a person homozygous for normal pigment (AA), A) half of the offspring are normal. B) half of the offspring are albinos. C) all offspring are normal. D) all offspring are albinos. E) None of these choices is correct.

The process of meiosis will _____ as the gametes are produced. A) cut the chromosome number by 1/3 B) cut the chromosome number by 1/2 C) double the chromosome number D) not change the chromosome number E) triple the chromosome number

Which of the following chromosome anomalies can be found in either sex? A) Turner's Syndrome (XO) B) Klinefelter's Syndrome (XXY) C) Down Syndrome (Trisomy 21) D) Barker's Syndrome E) They all can be found in either sex.

A mutation involving a single nucleotide is a _____ mutation. A) deletion B) duplication C) nondisjunction D) point E) aneuploidy

A mistake during segregation of chromosomes is called A) deletion. B) duplication. C) nondisjunction. D) point mutation. E) aneuploidy

Down Syndrome is an example of an aneuploidy called A) monosomy 21. B) trisomy 21. C) monosomy 23. D) trisomy 17. E) disomy 21.

What genetic disorder is the failure to produce clotting factors? A) albinism B) sickle-cell disease C) hemophilia D) Down syndrome E) achondroplasia

What genetic disorder is characterized by lack of skin, hair, eye coloration? A) albinism B) sickle-cell disease C) hemophilia D) Down syndrome E) achondroplasia

What genetic disorder is the inability to produce normal hemoglobin? A) albinism B) sickle-cell disease C) hemophilia D) Down syndrome E) achondroplasia

What genetic disorder is caused by having three chromosomes 21? A) albinism B) sickle-cell disease C) hemophilia D) Down syndrome E) achondroplasia

What genetic disorder is a type of dwarfism characterized by shortening of the upper and lower limbs? A) albinism B) sickle-cell disease C) hemophilia D) Down syndrome E) achondroplasia

What term means that both alleles are the same? A) locus B) alleles C) homozygous D) heterozygous E) karyotype

What term means that both alleles are different? A) locus B) alleles C) homozygous D) heterozygous E) karyotype

Genes that are passed from male to male are called A) structural genes. B) autosomes. C) genotypes. D) polygenic. E) y-linked.

The actual genetic constitution of an individual is its A) structural gene. B) autosome. C) genotype. D) polygenic. E) y-linked.

Chromosomes that are NOT associated with sex determination are known as A) structural genes. B) autosomes. C) genotypes. D) polygenic. E) y-linked.

When more than one gene pair is involved in an inheritance pattern, it is called A) structural gene. B) autosome. C) genotype. D) polygenic. E) y-linked.

The major organ systems develop during the germinal prenatal period.

What is the acrosomal reaction? A) The formation of the acrosome in the epididymis B) The activation of enzymes for action on the surface of the egg C) The release of ADP from the mitochondria on the midpiece D) The release of prostatic fluid to produce the semen

The thickened area of the blastocyst from which the embryo develops is called the _______________. A) inner cell mass B) trophoblast C) blastocele D) morula E) zygote

The process of forming three germ layers from the embryonic disk is called ______. A) gastrulation B) differentiation C) fertilization D) meiosis E) implantation

As parturition nears, the levels of progesterone ______ and the levels of estrogen ______. A) decrease; increase B) increase; decrease C) decrease; decrease D) increase; increase

In some neonates the foramen ovale does not close to form the fossa ovalis. This would be called a(n) _____. A) mutation B) congenital disorder C) teratogen D) genetic anomaly

Identify the hormone secreted during pregnancy that cause the ducts of the mammary glands to grow and branch when in high levels. A) Estrogen B) Progesterone C) Prolactin D) Growth hormone

Pulling to a standing position is a typical milestone for which age? A) 6 weeks B) 6 months C) 12 weeks D) 12 months E) 18 weeks

Atoms or molecules with unpaired electrons that can react with normal cells and cause damage are called ______. A) free radicals B) teratogens C) mutagens D) antioxidants E) vitamins

What term describes the inheritance of a trait which in the heterozygote has an intermediate expression between either allele? A) Incomplete penetrance B) Incomplete dominance C) Complete dominance D) Codominance

A non-albino female who is a carrier for the albino allele (Aa), mates with an albino (aa) male. What is the probability that their children will be albino? A) 0% B) 25% C) 50% D) 75% E) 100%

The most significant complication of infant prematurity is infant respiratory distress syndrome, which occurs because very young premature infants cannot produce ______________. A) surfactant B) blood C) oxygen D) erythropoietin E) growth hormone

The inclusion of ______________ in a woman's diet during the early stages of her pregnancy significantly reduces the risk for neural tube defects in her developing embryo. A) Vitamin E B) Vitamin D C) Vitamin A D) Folic acid E) Calcium

In the context of western medicine, the definition of death is different from that among poorer people with only low levels of medical care. One criterion of death is an isoelectric response of an electroencephalogram for ____ minutes. The ethics of tissue and organ donatio demand that multiple criteria be met before someone is declared to be dead. The most widely accepted definition of death is_______.

A __________ is a display of the chromosomes of a somatic cell during metaphase of mitosis. A) karyotype B) genome C) gamete D) locus