pregnancy & inheritance

As development proceeds, the differentiation of other embryonic cells is affected by small zygotic cells that __________. A. release RNA, polypeptides, and small proteins B. produce the three germ layers during gastrulation C. produce the initial stages of implantation D. are involved with the placental process

a

At the time of ovulation, the secondary oocyte leaving the follicle __________. A. is in metaphase II of meiosis B. has completed the second meiotic division C. is in prophase II of meiosis D. is in prophase I of meiosis

a

Before gestation, the uterus weighs about __________. A. 1 oz B. 1 lb C. 1 g D. 1 kg

a

During embryonic development, __________ primary germ cell layers develop. A. three B. two C. four D. five

a

During implantation, the inner cell mass of the blastocyst separates from the trophoblast, creating a fluid-filled chamber called the __________. A. amniotic cavity B. allantois C. blastodisc D. blastocoele

a

For a given trait, if the genotype is AA, the individual is __________. A. homozygous dominant B. heterozygous dominant C. homozygous recessive D. heterozygous recessive

a

For a given trait, if the genotype is Aa, the individual is __________. A. heterozygous B. homozygous dominant C. homozygous recessive D. homozygous

a

If albinism is a recessive trait, and an albino mother and a normal father with the genotype AA have an offspring, the child will __________. A. have normal coloration B. have blue eyes because of lack of pigmentation C. be an albino D. have abnormal pigmentation

a

Which of the following changes in organ systems does NOT occur as the result of aging? A. Rate of bone deposition declines. B. Coordination, memory, and intellectual function become impaired. C. Hormone production and sensitivity to hormones increase. D. Muscular strength and ability decrease.

c

Which of the following is NOT an enzyme found in the cap of the sperm? A. hyaluronidase B. acrosin C. testosterone D. All of these are found in the sperm cap.

c

Which of the following occurs in the event of "fraternal," or dizygotic, twins? A. The inner cell mass splits before gastrulation. B. The blastomeres separate early during cleavage. C. Two separate eggs are ovulated and fertilized. D. All of the listed responses are correct.

c

Which of the following statements about labor is FALSE? A. During the expulsion stage of labor, contractions may occur once every two to three minutes and may last a full minute each. B. Contractions during labor begin at the top of the uterus and flow toward the cervix, thus pushing the baby toward the vagina. C. During a cesarean section, a cut is made in the perineal muscles to allow the uterus to be opened enough to permit the passage of the baby's head. D. All of the listed responses are correct.

c

At the end of gestation, the uterus may weigh __________ lb. A. 1 B. 5 C. 11 D. 14

d

During adolescence, what are sex hormones responsible for? A. activation of the CNS centers for sexual activity B. deposition of bone and promotion of the closure of the epiphyseal plates in long bone C. stimulation of the growth of muscle fibers, increasing strength and endurance D. All of the listed responses are correct.

d

During gestation, the primary major compensatory adjustments include which of the following? A. increasing maternal requirements for nutrients B. increasing glomerular filtration rate C. increasing respiratory rate and tidal volume D. All of the listed responses are correct.

d

For a given trait, if the genotype is aa, the individual is __________. A. homozygous B. homozygous dominant C. heterozygous D. homozygous recessive

d

Home pregnancy tests detect the presence of __________. A. prolactin B. relaxin C. estrogen D. human chorionic gonadotropin

d

How are gametes different from ordinary somatic cells? A. They contain the full complement of chromosomes. B. Gametes are diploid, or 2n. C. The chromosome number doubles in gametes. D. They contain only half the normal number of chromosomes.

d

If an allele is dominant, it will be expressed in the phenotype __________. A. by the use of lowercase abbreviations B. by the use of capitalized abbreviations C. if both alleles agree on the outcome of the phenotype D. regardless of any conflicting instructions carried by the other allele

d

Infancy lasts until a child is _________ old. A. three months B. six months C. one year D. two years

d

Near the end of a full-term pregnancy, the calming effect of progesterone is counteracted by what mechanism? A. increasing estrogen levels B. prostaglandin production C. increasing oxytocin levels D. All of the listed responses are correct.

d

The creation of different types of cells during the processes of development is called __________. A. implantation B. fertilization C. maturity D. differentiation

d

The extraembryonic membranes that develop from the endoderm and mesoderm are the __________. A. yolk sac and allantois B. amnion and chorion C. allantois and chorion D. yolk sac and amnion

d

The first meiotic division __________. A. yields four functional spermatids in the male B. results in the separation of the duplicate chromosomes C. produces one functional ovum in the female D. reduces the number of chromosomes from 46 to 23

d

The first trimester does NOT include which of the following events? A. placentation B. cleavage C. blastocyst formation D. development of complete organ systems

d

The gradual modification of anatomical structures during development occurs during the period from __________. A. birth to maturity B. conception to birth C. birth to adolescence D. fertilization to maturity

d

The hormones produced by the placenta include which of the following? A. estrogen and progesterone B. human chorionic gonadotropin hormone C. relaxin and human placental lactogen D. All of the listed responses are correct.

d

The most dangerous period in prenatal or postnatal life is the __________. A. third trimester B. second trimester C. expulsion stage D. first trimester

d

In cases of gestational trophoblastic neoplasia, the trophoblast __________. A. divides excessively and spreads to other tissues, behaving much like a cancer B. fails to divide, and a spontaneous abortion occurs C. adheres itself to the uterine tube, resulting in the nondevelopment of the embryo D. adheres to the cervix, increasing the chances of a difficult or failed pregnancy

a

In general, a male with a sperm count of less than __________ million per milliliter is considered infertile. A. 20 B. 10 C. 1 D. 40

a

Organs and organ systems complete most of their development during the __________. A. second trimester B. time of placentation C. third trimester D. first trimester

a

Sterility in males may result from a sperm count of fewer than __________. A. 20 million sperm per mL B. 40 million sperm per mL C. 60 million sperm per mL D. 100 million sperm per mL

a

The completion of metaphase II, anaphase II, and telophase II produces __________. A. four gametes, each containing 23 chromosomes B. four gametes, each containing 46 chromosomes C. one gamete containing 23 chromosomes D. one gamete containing 46 chromosomes

a

The development stages that occur during cleavage follow which sequence? A. zygote, blastomeres, morula, blastocyst B. yolk sac, amnion, allantois, chorion C. blastocyst, blastomeres, trophoblast, morula D. amnion, allantois, chorion, yolk sac

a

The extraembryonic membrane that begins as an outpocketing of endoderm and whose base gives rise to the urinary bladder is the __________. A. allantois B. yolk sac C. chorion D. amnion

a

The inner cell mass does NOT form which of the following structures? A. trophoblast B. mesoderm C. endoderm D. yolk sac

a

The normal male genotype is __________, and the normal female genotype is __________. A. XY; XX B. Y; X C. X; Y D. XX; XY

a

The total number of genes in human DNA, as identified by the Human Genome Project, is __________. A. 25,000 to 30,000 B. 50,000 to 100,000 C. 100,000 to 500,000 D. more than 1 million

a

The zygote contains __________ chromosomes. A. 46 B. 23 C. 48 D. 92

a

What does the term inheritance refer to? A. transfer of genetically determined characteristics from generation to generation B. study of the mechanisms responsible for the passing of traits C. development occurring at birth and continuing to maturity D. None of the listed responses is correct.

a

Which of the following is NOT a physiological effect on the mother's body during pregnancy? A. Folic acid needs decrease. B. Maternal glomerular filtration rate increases by roughly 50 percent. C. There is an increase in tidal volume. D. There is an increase in size and activity of mammary glands.

a

Which of the following is NOT an effect of aging on organ systems? A. increase in peripheral blood flow B. increase in the impairment of the reproductive system until a state of nonfunction is achieved, such as menopause C. reduction in the sensitivity and activity of the immune system D. decrease in peristalsis and muscle tone along the digestive tract

a

Which of the following occurs during the first trimester? A. The rudiments of major organ systems appear. B. Major organs become functional. C. The development of major organ systems takes place. D. None of these events occurs during the first trimester.

a

Which of the following occurs during the third trimester? A. Major organ systems become functional. B. The development of major organ systems takes place. C. The rudiments of major organ systems appear. D. None of these events occurs during the third trimester.

a

Which of the following syndromes would be found in a female who has only one sex chromosome? A. Turner syndrome B. fragile X syndrome C. Klinefelter's syndrome D. Patau syndrome

a

An ectopic pregnancy refers to __________. A. implantation occurring within the endometrium B. implantation occurring somewhere other than within the uterus C. the formation of extraembryonic membranes in the uterus D. the formation of a gestational neoplasm

b

During fertilization, the process of cortical reaction is important in __________. A. ensuring the fusion of the sperm nucleus with the egg nucleus B. preventing penetration of the egg by additional sperm C. producing a condition known as polyspermy D. helping the sperm penetrate the corona radiata

b

During oocyte activation, the process that is important in preventing penetration by more than one sperm is the __________. A. process of amphimixis B. cortical reaction C. process of monospermy D. process of capacitation

b

Embryogenesis is the process that establishes the foundation for __________. A. implantation to occur B. all the major organ systems C. the formation of the blastocyst D. the formation of the placenta

b

Embryologic development __________. A. ends after implantation has occurred B. ends two months after conception C. begins at the ninth week following conception D. continues until birth

b

Fertilization is the fusion of two __________ cells, each containing __________ chromosomes. A. diploid; 23 B. haploid; 23 C. diploid; 46 D. haploid; 46

b

Germ-layer formation results from the process of __________. A. parturition B. gastrulation C. embryogenesis D. organogenesis

b

Gestation can be divided into __________, each about three months long. A. seasons B. trimesters C. quarters D. semesters

b

In a person with sickle cell anemia, what triggers the change in the shape of red blood cells to a sickle shape? A. a decrease in oxygen in the internal organs B. a decrease in the PO2 in peripheral capillaries C. a decrease in the PCO2 in the lungs D. All of the listed responses are correct.

b

The chorion develops from the __________. A. endoderm and mesoderm B. mesoderm and trophoblast C. trophoblast and endoderm D. ectoderm and mesoderm

b

The fusion of male and female pronuclei is an event termed __________. A. fertilization B. amphimixis C. polyspermy D. oocyte activation

b

The umbilical cord, or umbilical stalk, contains __________. A. paired umbilical arteries and the amnion B. the allantois, blood vessels, and yolk stalk C. a single umbilical vein and the chorion D. the amnion, allantois, and chorion

b

The yolk sac contains contributions from which germ cell layer(s)? A. ectoderm B. both mesoderm and endoderm C. endoderm D. mesoderm

b

What is the extraembryonic membrane that gives rise to the urinary bladder? A. amnion B. allantois C. chorion D. None of the listed responses is correct.

b

What is the term for a gene's position on a chromosome? A. allele B. locus C. karyotype D. None of the listed responses is correct.

b

Which of the following does NOT occur during the transition from fetus to neonate? A. The pattern of cardiovascular circulation changes after the lungs expand. B. Typical heart and respiratory rates are lower in neonates than in adults. C. The lungs at birth are collapsed and must be inflated by massive and powerful inspiratory movements. D. Materials collected in the relatively inactive fetal digestive tract are excreted in the first few days of life.

b

Which of the following statements about the second trimester is FALSE? A. The alveoli form during the second trimester. B. The mammary glands form during the second trimester. C. Hairs and sebaceous glands are formed during the second trimester. D. The fetus begins to move during the second trimester.

b

Which of the following statements concerning placentation is FALSE? A. Placental functions are concentrated in a disc-shaped area called the decidua basalis. B. The decidua parietalis is the portion of the uterine endometrium in direct contact with the chorion. C. The fetus is connected to the placenta by the umbilical cord. D. The decidua capsularis of the placenta does not participate in nutrient exchange.

b

Which systems that were relatively nonfunctional during the fetus's prenatal period must become functional at birth? A. the endocrine, nervous, and circulatory systems B. the respiratory, digestive, and urinary systems C. the circulatory, muscular, and skeletal systems D. the integumentary, reproductive, and nervous systems

b

A person who is heterozygous for a trait has which of the following characteristics? A. no alleles for a given gene and will thus not be able to phenotypically express the trait B. two identical alleles for a given gene C. two different alleles for a given gene D. None of the listed responses is correct.

c

Complete dilation of the cervix marks the beginning of __________. A. the placental stage of labor B. premature labor C. the expulsion stage of labor D. the dilation stage of labor

c

Delivery of the fetus is known as __________. A. matriculation B. peristalsis C. parturition D. embryogenesis

c

Each of the following contributes to the onset of labor contractions EXCEPT __________. A. rising prostaglandin levels B. rising oxytocin levels C. rising progesterone levels D. rising estrogen levels

c

Exchange between the embryonic and maternal circulations occurs by diffusion across the syncytial and cellular trophoblast layers via __________. A. the allantois B. the yolk sac C. the chorionic blood vessels D. the umbilicus

c

Growth ceases at __________. A. senescence B. adolescence C. maturity D. puberty

c

If one female X chromosome of an allele pair contains a sex-linked character for color blindness, what would the individual be? A. color blind B. color blind in one eye C. normal D. Any of these is possible.

c

In terms of genetic inheritance, the penetrance of a trait refers to __________. A. phenotypes that are determined by a single allele pair B. stimuli that result in abnormal development C. the percentage of individuals with a particular genotype who show the "expected" phenotype D. the extent to which a particular allele is expressed when it is present

c

Karyotyping is the determination of __________. A. the stages of prenatal development B. an individual's stage of labor C. an individual's chromosome complement D. the life stages of an individual

c

Labor has traditionally been divided into __________ stages. A. two B. four C. three D. five

c

Prostaglandins in the endometrium __________. A. initiate the process of organogenesis B. cause an increase in the maternal blood volume C. stimulate smooth muscle contractions D. cause the mammary glands to begin secretory activity

c

The amnion contains contributions from which germ cell layer(s)? A. mesoderm B. ectoderm C. ectoderm and mesoderm D. endoderm

c

The formation of extraembryonic membranes occurs in the correct sequential steps, which are __________. A. amnion, allantois, chorion, and yolk sac B. blastomeres, morula, blastocyst, and trophoblast C. yolk sac, amnion, allantois, and chorion D. blastocyst, trophoblast, amnion, and chorion

c

The fusion of the male pronucleus with the female pronucleus is called __________. A. cytokinesis B. spermiogenesis C. amphimixis D. homeostasis

c

The normal chromosome complement of a typical somatic, or body, cell is __________. A. n, or haploid B. 23 C. 46 D. 92

c

The stages in labor do NOT include __________. A. expulsion B. dilation C. implantation D. placental

c

Throughout embryonic and fetal development, metabolic wastes generated by the fetus are eliminated by transfer to the __________. A. amniotic fluid B. chorion C. maternal circulation D. allantois

c

Which of the following statements concerning gastrulation is FALSE? A. At the primitive streak, migrating cells leave the surface and move between the surface layer and the deep layer. B. The three germ layers are established during gastrulation. C. During gastrulation, the deep layer becomes the ectoderm. D. During gastrulation, cells in specific areas of the surface move toward the primitive streak.

c

Alterations in genetic activity during development occur as a result of __________. A. conception B. the chromosome complement in the nucleus of the cell C. the maturation of the sperm and ovum D. differences in the cytoplasmic composition of individual cells

d

At puberty, increased hormone production and sexual maturation are promoted by each of the following EXCEPT one. Identify the exception. A. Ovarian and testicular cells become more sensitive to the pituitary gonadotropins. B. The anterior lobe of the pituitary gland becomes more sensitive to GnRH and elevates the circulating levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). C. The hypothalamus increases its production of GnRH, the gonadotropin-releasing hormone. D. Sex hormones from the gonads stimulate the hypothalamus, producing GnRH, the gonadotropin-releasing hormone.

d

The presence of freckles on the skin is __________. A. a side effect of teratogens on a developing embryo B. an example of polygenic inheritance and is linked to Huntington disease C. determined by multiple genes found on sex chromosomes D. an example of simple inheritance, with the recessive form being the absence of freckles on the skin

d

The stretching of the myometrium during gestation is associated with a gradual increase in the __________. A. size of the developing fetus B. excessive secretion of progesterone C. amount of fluid in the uterus D. rates of spontaneous smooth-muscle contractions

d

Which of the following is/are produced by the placenta? A. progesterone B. human chorionic gonadotropin (HCG) C. placental prolactin D. All of the listed responses are correct.

d

Which of the following statements about Down's syndrome is correct? A. A degree of mental retardation as well as distinct physical features will be present. B. The affected individual has three copies of chromosome 21. C. The syndrome is caused by an error in meiosis. D. All of the listed responses are correct.

d

Which of the following statements about amniocentesis is correct? A. A sample of the placenta is removed for examination. B. Sampling of the placenta occurs within the first trimester. C. More than 100 disorders can be diagnosed by examining the placental sample. D. None of the listed responses is correct.

d

Which of the following statements about fertilization is FALSE? A. Of the roughly 200 million spermatozoa introduced into the vagina in a typical ejaculation, fewer than 100 actually reach the ovum. B. The ovum must provide the nourishment and genetic programming to support embryonic development for nearly a week. C. Fertilization involves the fusion of two haploid gametes. D. Normal fertilization occurs in the body of the uterus.

d