Anatomy and Physiology: Chapter 29 Development and Inheritance

Which of the following statements concerning gastrulation is FALSE?

During gastrulation, the deep layer becomes the ectoderm.

Which of the following is NOT a physiological effect on the mother's body during pregnancy?

Folic acid needs decrease.

which of the following occurs during the third trimester?

Major organ systems become functional.

Which of the following is NOT an effect of pregnancy on the mother?

Maternal blood volume decreases.

Which of the following statements about fertilization is FALSE?

Normal fertilization occurs in the body of the uterus.

The normal male genotype is __________, and the normal female genotype is __________.

XY; XX

The extraembryonic membrane that begins as an outpocketing of endoderm and whose base gives rise to the urinary bladder is the __________.

allantois

What is the extraembryonic membrane that gives rise to the urinary bladder?

allantois

During implantation, the inner cell mass of the blastocyst separates from the trophoblast, creating a fluid-filled chamber called the __________.

amniotic cavity

The fusion of male and female pronuclei is an event termed __________.

amphimixis

The fusion of the male pronucleus with the female pronucleus is called __________.

amphimixis

The amnion contains contributions from which germ cell layer(s)?

ectoderm and mesoderm

Which of the following is the term for the events that occur during the first two months of development after fertilization?

embryological development

Embryologic development __________.

ends two months after conception

Fertilization is the fusion of two __________ cells, each containing __________ chromosomes.

haploid; 23

If albinism is a recessive trait, and an albino mother and a normal father with the genotype AA have an offspring, the child will __________.

have normal coloration

For a given trait, if the genotype is Aa, the individual is __________.

heterozygous

What is the term for having two different alleles for one gene?

heterozygous

For a given trait, if the genotype is AA, the individual is __________.

homozygous dominant

For a given trait, if the genotype is aa, the individual is __________.

homozygous recessive

Home pregnancy tests detect the presence of __________.

human chorionic gonadotropin

Which of the following is/are produced by the placenta?

human chorionic gonadotropin (HCG) placental prolactin progesterone correct: All of the listed responses are correct.

The hormones produced by the placenta include which of the following?

human chorionic gonadotropin hormone estrogen and progesterone relaxin and human placental lactogen correct: All of the listed responses are correct.

The stages in labor do NOT include __________.

implantation

The term for the event that occurs when the blastocyst contacts the endometrium and grows into the endometrium is __________.

implantation

An ectopic pregnancy refers to __________.

implantation occurring somewhere other than within the uterus

Which of the following is NOT an effect of aging on organ systems?

increase in peripheral blood flow

Near the end of a full-term pregnancy, the calming effect of progesterone is counteracted by what mechanism?

increasing oxytocin levels increasing estrogen levels prostaglandin production correct: All of the listed responses are correct.

During gestation, the primary major compensatory adjustments include which of the following?

increasing respiratory rate and tidal volume increasing maternal requirements for nutrients increasing glomerular filtration rate Correct: All of the listed responses are correct.

At the time of ovulation, the secondary oocyte leaving the follicle __________.

is in metaphase II of meiosis

What is the term for a gene's position on a chromosome?

locus

Delivery of the fetus is known as __________.

parturition

What is the name of the medical specialty that focuses on the postnatal period from infancy through adolescence?

pediatrics

During fertilization, the process of cortical reaction is important in __________.

preventing penetration of the egg by additional sperm

The stretching of the myometrium during gestation is associated with a gradual increase in the __________.

rates of spontaneous smooth-muscle contractions

The first meiotic division __________.

reduces the number of chromosomes from 46 to 23

If an allele is dominant, it will be expressed in the phenotype __________.

regardless of any conflicting instructions carried by the other allele

As development proceeds, the differentiation of other embryonic cells is affected by small zygotic cells that __________.

release RNA, polypeptides, and small proteins

Which of the following oppose(s) progesterone and begin(s) labor?

rising oxytocin rising estrogen prostaglandin production Correct: All of the listed responses are correct.

Each of the following contributes to the onset of labor contractions EXCEPT __________.

rising progesterone levels

Organs and organ systems complete most of their development during the __________

second trimester

Which of the following is the term for aging, or growing old?

senescence

What is the term for the type of inheritance in which the allele is found on the X chromosome and therefore most often affects males?

sex-linked inheritance

Prostaglandins in the endometrium __________.

stimulate smooth muscle contraction

Which of the following is NOT an enzyme found in the cap of the sperm?

testosterone

The umbilical cord, or umbilical stalk, contains __________.

the allantois, blood vessels, and yolk stalk

Exchange between the embryonic and maternal circulations occurs by diffusion across the syncytial and cellular trophoblast layers via __________.

the chorionic blood vessels

The formation of extraembryonic membranes occurs in the correct sequential steps, which are __________.

yolk sac, amnion, allantois, and chorion

The development stages that occur during cleavage follow which sequence?

zygote, blastomeres, morula, blastocyst

Labor has traditionally been divided into __________ stages.

three

What does the term inheritance refer to?

transfer of genetically determined characteristics from generation to generation

Gestation can be divided into __________, each about three months long.

trimesters

Gestation is divided into __________.

trimesters

The inner cell mass does NOT form which of the following structures?

trophoblast

Fraternal, or dizygotic, twins result from __________.

two oocytes being ovulated in one cycle

Infancy lasts until a child is _________ old.

two years

Fertilization usually occurs in the __________.

uterine tube

In strict dominance, a dominant allele __________.

will be expressed 100 percent of the time when paired with a recessive allele

The extraembryonic membranes that develop from the endoderm and mesoderm are the __________.

yolk sac and amnion

Before gestation, the uterus weighs about __________.

1 oz

At the end of gestation, the uterus may weigh __________ lb.

14

In general, a male with a sperm count of less than __________ million per milliliter is considered infertile.

20

Sterility in males may result from a sperm count of fewer than __________.

20 million sperm per mL

The total number of genes in human DNA, as identified by the Human Genome Project, is __________.

25,000 to 30,000

The normal chromosome complement of a typical somatic, or body, cell is __________.

46

The zygote contains __________ chromosomes.

46

Which of the following statements concerning placentation is FALSE?

The decidua parietalis is the portion of the uterine endometrium in direct contact with the chorion.

Which of the following does NOT happen during oocyte activation?

The first cleavage is completed.

Which of the following statements about the second trimester is FALSE?

The mammary glands form during the second trimester.

Which of the following occurs during the first trimester?

The rudiments of major organ systems appear.

How are gametes different from ordinary somatic cells?

They contain only half the normal number of chromosomes.

Which of the following occurs in the event of "fraternal," or dizygotic, twins?

Two separate eggs are ovulated and fertilized.

Embryogenesis is the process that establishes the foundation for __________.

all the major organ systems

The presence of freckles on the skin is __________.

an example of simple inheritance, with the recessive form being the absence of freckles on the skin

Karyotyping is the determination of __________.

an individual's chromosome complement

Gastrulation produces three germ layers. Which of the following is NOT one of the germ layers?

blastocoele

A hollow ball of cells created by cleavage is called a __________.

blastocyst

The yolk sac contains contributions from which germ cell layer(s)?

both mesoderm and endoderm

Which of the following forms the placenta?

chorion

A sequence of cell divisions that begins after fertilization is called __________.

cleavage

The first secretion produced for the baby by the mammary glands, which contains more protein and less fat, is __________.

colostrum

During oocyte activation, the process that is important in preventing penetration by more than one sperm is the __________.

cortical reaction

During adolescence, what are sex hormones responsible for?

deposition of bone and promotion of the closure of the epiphyseal plates in long bone activation of the CNS centers for sexual activity stimulation of the growth of muscle fibers, increasing strength and endurance Correct: All of the listed responses are correct.

The first trimester does NOT include which of the following events?

development of complete organ systems

Alterations in genetic activity during development occur as a result of __________.

differences in the cytoplasmic composition of individual cells

The creation of different types of cells during the processes of development is called __________.

differentiation

In cases of gestational trophoblastic neoplasia, the trophoblast __________.

divides excessively and spreads to other tissues, behaving much like a cancer

The gradual modification of anatomical structures during development occurs during the period from __________.

fertilization to maturity

Which of the following is the term for the developmental events that occur from nine weeks to birth?

fetal development

The most dangerous period in prenatal or postnatal life is the __________.

first trimester

The completion of metaphase II, anaphase II, and telophase II produces __________.

four gametes, each containing 23 chromosomes

Germ-layer formation results from the process of __________.

gastrulation

Throughout embryonic and fetal development, metabolic wastes generated by the fetus are eliminated by transfer to the __________.

maternal circulation

The chorion develops from the __________.

mesoderm and trophoblast

If one female X chromosome of an allele pair contains a sex-linked character for color blindness, what would the individual be?

normal

The first stage of labor, during which the cervix opens, is called __________.

the dilation stage

Complete dilation of the cervix marks the beginning of __________.

the expulsion stage of labor

In terms of genetic inheritance, the penetrance of a trait refers to __________.

the percentage of individuals with a particular genotype who show the "expected" phenotype

Which systems that were relatively nonfunctional during the fetus's prenatal period must become functional at birth?

the respiratory, digestive, and urinary systems

During embryonic development, __________ primary germ cell layers develop.

three