AP2 CH29 Developement & Inheritance

Amniotic fluid

(b) 2, 4, and 5 (2) acts as a fetal shock absorber, (4) helps regulate fetal body temperature, (5) prevents adhesions between the skin of the fetus and surrounding tissues

Which of the following statements is correct?

(b) Occasionally an error in meiosis called nondisjunction results in an abnormal number of chromosomes

Which of the following structures develop during the fourth week after fertilization?

(c) 1,2,3,4,and5 (1) embryonic folding, (2) the neural tube, (3) otic placode (beginning of the ear), (4) beginning of the eyes, (5) upper and lower limb buds

Which of the following are maternal changes that occur during pregnancy?

(d) 1,3,and5 (1) altered pulmonary function;(3) weight gain;(5) edema and possible varicose veins.

Indicate whether the following statement is true or false. Labor is an example of a negative feedback cycle that ends with the birth of the infant.

False

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

Nutrient and vitamin needs increase 80-100 percent.

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

XY; XX

The extraembryonic membrane that gives rise to the urinary bladder is the __________.

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

Embryologic development __________.

ends two months after conception

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 possibilities are indicated by Aa, the individual is ?

heterozygous

For a given trait, if the possibilities are indicated by AA, the individual is __________.

homozygous dominant

For a given trait, if the possibilities are indicated by aa, the individual is __________.

homozygous recessive

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

A gene's position on a chromosome is termed the __________.

locus

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

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 include __________.

yolk sac, amnion, allantois, and chorion

The development stages that occur during cleavage follow which sequence?

zygote, blastomeres, morula, blastocyst

The term inheritance refers to the __________.

transfer of genetically determined characteristics form generation to generation

Infancy lasts until a child is _________ old.

two years

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

yolk sac and amnion

Which of the following are true concerning fertilization?

(e) 2,4,and5 (2) The binding of specific membrane proteins in the sperm head to ZP3 causes the release of acrosomal contents.(4) Depolar- ization of the cell membrane of the secondary oocyte inhibits fertilization by more than one sperm. (5) The oocyte completes meiosis II after fertilization.

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

During adolescence, sex hormones are responsible for __________.

All of the listed responses are correct.

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

All of the listed responses are correct.

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

All of the listed responses are correct.

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

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

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 sex-linked character for color blindness, the individual would 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

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

the respiratory, digestive, and urinary systems