ch 29 development and fertility

What is the correct sequence of stages in the process of delivering a baby?

Dilation; expulsion; placental

amphimixis

Fusion of female pronucleus and male pronucleus Moment of conception Cell becomes a zygote with 46 chromosomes Fertilization is complete

How do gametes differ from ordinary somatic cells?

Gametes contain only half the normal number of chromosomes.

What is the hormone that causes milk ejection (let-down)?

Oxytocin

Embryogenesis is the process that establishes the foundation for __________.

all the major organ systems

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

Embryologic development __________.

ends two months after conception

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

have normal coloration

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

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

locus

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

preventing penetration of the egg by an additional sperm

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

rates of spontaneous smooth-muscle contractions

first meiotic division

reduces the number of chromosomes from 46 to 23

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

release RNA, polypeptides, and small proteins

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

second trimester

Prostaglandins in the endometrium __________.

stimulate smooth muscle contractions

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

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

yolk sac ad amnion

What are the criteria for a premature delivery?

Delivery from 28 to 36 weeks

Infancy lasts until a child is _________ old.

2 years

As identified by the Human Genome Project, the total number of protein-encoding genes in human DNA is __________.

20,000 to 25,000

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

25k-30k

What is the correct sequence of events going from the zygote to the fetus?

Cleavage; implantation; placentation; embryogenesis

What is the difference between colostrum and breast milk?

Colostrum has more protein and less fat than breast milk.

Which of the following is not a reason why maternal blood volume increases during pregnancy?

Decreased maternal PCO2

What is the biggest change in the baby's cardiovascular system after birth?

Separation of the pulmonary and systemic blood circuits

What happens in the process of hatching?

The zona pellucida is shed from the blastocyst.

Karyotyping is the determination of __________.

an individual's chromosome complement

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

cortical reaction

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

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

fertilization to maturity

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

folic acid needs decrease

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

Which hormone is tested for in a pregnancy test?

hCG

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

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