Chapter 27 Quizzes

*A person's original chromosomes and their component genes constitute that person's* -allele. -locus. -phenotype. -genotype. -autosomal inheritance.

genotype.

*A zygote whose genotype is XY will develop as a* -male. -female.

male.

*After fertilization, the first cell division is completed* -within a few seconds. -about 6 hours later. -more than a day later. -in 12 hours. -within the hour.

more than a day later.

*The mesoderm forms* -epidermis. -the lining of the digestive tract. -respiratory epithelium. -muscle. the brain.

muscle.

*The ectoderm forms* -the urinary system. -the lining of the stomach and small intestine. -muscle. -neural tissues. -blood.

neural tissues.

*Which of the following does NOT occur during the first trimester?* -gastrulation -cleavage -implantation -organs become functional -separation of blastomeres to form monozygotic twins

organs become functional

*Which hormone stimulates the milk let-down reflex?* -oxytocin -progesterone -estrogen -GnRH -relaxin

oxytocin

*The traits of an individual controlled by his or her genotype are his or her* -phenotype. -alleles. -epigenome. -karyotype. -genotypical inheritances.

phenotype.

*The placenta is expelled from the uterus during the ________ stage of labor.* -dilation -expulsion -contraction -afterbirth -placental

placental

*The placenta is NOT a source of which of the following hormones?* -hCG -progesterone -placental lactogen -relaxin -prolactin

prolactin

*The hormone that increases the flexibility of the pubic symphysis during pregnancy is* -oxytocin. -relaxin. -human placental lactogen. -progesterone. -human chorionic gonadotropin.

relaxin.

*During amphimixis,* -sperm become capacitated. -the male and female pronuclei fuse. -meiosis occurs. -gametes are formed. -the zygote is formed with 46 chromosomes.

the male and female pronuclei fuse.

*The endoderm forms* -muscle. -neural tissue. -skin. -blood. -the urinary bladder.

the urinary bladder.

*During gastrulation,* -three germ layers are formed. -the placenta penetrates the endometrium. -the neural tube closes. -blastomeres form. -the blastomeres fuse.

three germ layers are formed.

*Deoxygenated blood is carried to the placenta by the* -umbilical vein. -umbilical arteries.

umbilical arteries.

*Oxygenated blood is carried away from the placenta by the* -umbilical arteries. -umbilical vein.

umbilical vein.

*The embryonic heart starts beating as blood begins to flow through chorionic vessels at approximately ________ of development.* -day 12 -day 3 -week 2 -the second trimester -week 3

week 3

*Attachment to and penetration of the endometrium by the blastocyst is referred to as* -cleavage. -implantation. -embryogenesis. -placentation. -fertilization.

implantation.

*Molly is homozygous for the dominant black hair trait. Therefore,* -Molly has red hair. -Molly has black hair. -Molly is a carrier for the black hair trait. -Molly's hair color cannot be determined from this information.

Molly has black hair.

*A ________ is used to show all possible combinations of genes that can result from a given parental cross.* -phenotype -karyotype -pedigree -family tree -Punnett square

Punnett square

*A child born with one lone X chromosome will have* -Tay-Sachs disease. -Down syndrome. -acromegaly. -Turner's syndrome. -Klinefelter's syndrome.

Turner's syndrome.

*In simple autosomal inheritance, phenotypic characters are determined, or controlled, by* -a single pair of alleles. -the genes on the Y chromosome. -the action of a single gene. -regulator genes on a different chromosome. -multiple alleles.

a single pair of alleles.

*Which of the following is a puberty-related change caused by increased testosterone levels?* -loss of terminal hairs on the face and chest -replication of skeletal muscle fibers -decreased erythropoiesis -thinning of the vocal folds -accelerated bone deposition and skeletal growth

accelerated bone deposition and skeletal growth

*The various forms of any one gene are called* -homologous. -autosomes. -alleles. -homozygous. -heterozygous.

alleles.

*The trophoblast has many of the characteristics of ________ cells.* -cardiac -smooth muscle -cancer -infectious -None of the answers is correct.

cancer

*The gradual modification of anatomical structures during the period from conception to maturity is* -embryogenesis. -development. -capacitation. -differentiation. -All of the answers are correct.

development.

*The oval, three-layered sheet produced by gastrulation is called the* -embryo. -inner cell mass. -embryonic disc. -ectoderm. -yolk sac.

embryonic disc.

*Which of the following hormones is the cause of most puberty-related changes in a female?* -chorionic gonadotropin -progesterone -relaxin -oxytocin -estrogen

estrogen

*A zygote whose genotype is XX will develop as a* -male. -female.

female.

*The infancy stage of life is considered to be over when the baby reaches ________ of age.* -2 years -18 months -1 month -6 months -1 year

1 year

*How many chromosomes do human somatic cells contain?* -44 -92 -46 -22 -23

46

*Trisomy 21 is the clinical term for* -amyotrophic lateral sclerosis. -Down syndrome. -Marfan's syndrome. -Klinefelter syndrome. -fetal alcohol syndrome.

Down syndrome.

*________ is the time spent in growing within the uterus.* -Pregnancy -Development -Gastrulation -Embryonization -Gestation

Gestation