Question 1

List and briefly characterize the three trimesters of gestation.

Accepted Answer

For convenience, we think of the gestation period as consisting of three integrated trimesters, each lasting 3 months in duration: (1) The first trimester is the period of embryological and early fetal development. During this period, the rudiments of all the major organ systems appear. (2) The second trimester is dominated by the development of organs and organ systems, a process that nears completion by the end of the sixth month. During this period, body shape and proportions change; by the end of this trimester, the fetus looks distinctively human. (3) The third trimester is characterized by the largest fetal weight gain and deposition of adipose tissue. Early in the third trimester, most of the fetus's major organ systems become fully functional.

Question 2

The blood vessel that carries oxygenated blood away from the placenta is the ________.

Accepted Answer

umbilical vein

Question 3

A blastocyst is a(n)

Accepted Answer

A)  extraembryonic membrane. 
B)  solid ball of cells. 
C)  hollow ball of cells. 
D)  portion of the placenta. 
E)  origin of the urinary bladder. 
A)  extraembryonic membrane. 
B)  solid ball of cells. 
C)  hollow ball of cells. 
D)  portion of the placenta. 
E)  origin of the urinary bladder. C

Question 4

By day 12 of embryonic development, mesoderm begins to form through

Accepted Answer

A)  embryolization. 
B)  gastrulation. 
C)  mitosis. 
D)  meiosis. 
E)  none of the above 
A)  embryolization. 
B)  gastrulation. 
C)  mitosis. 
D)  meiosis. 
E)  none of the above

Question 5

The stage of labor during which the fetus emerges from the vagina is called the ________ stage.

Accepted Answer

A)  emergence 
B)  dilation 
C)  placental 
D)  expulsion 
E)  fetal 
A)  emergence 
B)  dilation 
C)  placental 
D)  expulsion 
E)  fetal

Question 6

The ________ stage is the stage of labor during which the placenta is expelled from the uterus.

Accepted Answer

The answer of The ________ stage is the stage of...

Question 7

During amphimixis,

Accepted Answer

A)  sperm become capacitated. 
B)  the ovum finishes meiosis II. 
C)  the male and female pronuclei fuse. 
D)  meiosis occurs. 
E)  gametes are formed. 
A)  sperm become capacitated. 
B)  the ovum finishes meiosis II. 
C)  the male and female pronuclei fuse. 
D)  meiosis occurs. 
E)  gametes are formed.

Question 8

Which of these is not one of the extraembryonic membranes?

Accepted Answer

A)  yolk sac 
B)  amnion 
C)  allantois 
D)  chorion 
E)  umbilical cord 
A)  yolk sac 
B)  amnion 
C)  allantois 
D)  chorion 
E)  umbilical cord

Question 9

The ectoderm forms

Accepted Answer

A)  muscle. 
B)  blood. 
C)  neural tissues. 
D)  the lining of the stomach and small intestine. 
E)  the urinary system. 
A)  muscle. 
B)  blood. 
C)  neural tissues. 
D)  the lining of the stomach and small intestine. 
E)  the urinary system.

Question 10

The endoderm forms

Accepted Answer

A)  muscle. 
B)  blood. 
C)  neural tissue. 
D)  skin. 
E)  the urinary bladder. 
A)  muscle. 
B)  blood. 
C)  neural tissue. 
D)  skin. 
E)  the urinary bladder.

Question 11

How many chromosomes do human somatic cells contain?

Accepted Answer

The answer of How many chromosomes do human somatic cells...

Question 12

The process of cell division that divides the cytoplasm of the zygote among blastomeres is called

Accepted Answer

A)  cleavage. 
B)  implantation. 
C)  placentation. 
D)  embryogenesis. 
E)  blastulation. 
A)  cleavage. 
B)  implantation. 
C)  placentation. 
D)  embryogenesis. 
E)  blastulation.

Question 13

In polygenic inheritance, phenotypic characters are

Accepted Answer

A)  determined by a double pair of alleles. 
B)  determined by interactions among several genes. 
C)  determined by multiple copies of a single gene. 
D)  always controlled by genes on the same chromosome. 
E)  determined by the genes on the Y chromosome. 
A)  determined by a double pair of alleles. 
B)  determined by interactions among several genes. 
C)  determined by multiple copies of a single gene. 
D)  always controlled by genes on the same chromosome. 
E)  determined by the genes on the Y chromosome.

Question 14

The individual cells produced by cleavage are called

Accepted Answer

A)  embryos. 
B)  blastomeres. 
C)  blastocytes. 
D)  blastocysts. 
E)  zygotes. 
A)  embryos. 
B)  blastomeres. 
C)  blastocytes. 
D)  blastocysts. 
E)  zygotes.

Question 15

Completion of cytokinesis leads to

Accepted Answer

A)  a doubling of blastomere number. 
B)  a division of the cytoplasm into two portions. 
C)  interphase. 
D)  all of the above 
E)  none of the above 
A)  a doubling of blastomere number. 
B)  a division of the cytoplasm into two portions. 
C)  interphase. 
D)  all of the above 
E)  none of the above

Question 16

A(n) ________ allele is expressed only when homozygous.

Accepted Answer

The answer of A(n) ________ allele is expressed only when...

Question 17

Outline the events that take place between exposure of the oocyte to spermatozoa and formation of the first blastomere pair.

Accepted Answer

Powerful acrosomal hydrolases released f

Question 18

The prostaglandins produced in the endometrium

Accepted Answer

A)  initiate the release of oxytocin for parturition. 
B)  stimulate smooth muscle contractions. 
C)  initiate secretory activity in the mammary glands. 
D)  all of the above 
E)  none of the above 
A)  initiate the release of oxytocin for parturition. 
B)  stimulate smooth muscle contractions. 
C)  initiate secretory activity in the mammary glands. 
D)  all of the above 
E)  none of the above

Question 19

The original 46 chromosomes and their component genes constitute an individual's ________.

Accepted Answer

The answer of The original 46 chromosomes and their component...

Question 20

Figure 26-2 Fetus at 10 Weeks
Use Figure 26-2 to answer the following questions:
-Identify the structure labeled "4."

Accepted Answer

A)  amnion 
B)  chorion 
C)  decidua basalis 
D)  placenta 
E)  endometrium 
A)  amnion 
B)  chorion 
C)  decidua basalis 
D)  placenta 
E)  endometrium

Exam 26: Development and Inheritance

List and briefly characterize the three trimesters of gestation.

The blood vessel that carries oxygenated blood away from the placenta is the ________.

A blastocyst is a(n)

By day 12 of embryonic development, mesoderm begins to form through

The stage of labor during which the fetus emerges from the vagina is called the ________ stage.

The ________ stage is the stage of labor during which the placenta is expelled from the uterus.

During amphimixis,

Which of these is not one of the extraembryonic membranes?

The ectoderm forms

The endoderm forms

How many chromosomes do human somatic cells contain?

The process of cell division that divides the cytoplasm of the zygote among blastomeres is called

In polygenic inheritance, phenotypic characters are

The individual cells produced by cleavage are called

Completion of cytokinesis leads to

A(n) ________ allele is expressed only when homozygous.

Outline the events that take place between exposure of the oocyte to spermatozoa and formation of the first blastomere pair.

The prostaglandins produced in the endometrium

The original 46 chromosomes and their component genes constitute an individual's ________.

Figure 26-2 Fetus at 10 Weeks Use Figure 26-2 to answer the following questions: -Identify the structure labeled "4."

An Introduction to Anatomy and Physiology

Chemical Level of Organization

Cellular Level of Organization

Tissue Level of Organization

The Integumentary System

Osseous Tissue and Bone Structure

The Skeleton

Articulations

Skeletal Muscle Tissue

The Muscular System

Neural Tissue

The Spinal Cord, Spinal Nerves, and Spinal Reflexes

The Brain and Cranial Nerves

The Autonomic Nervous System

The Special Senses

The Endocrine System

Blood and Blood Vessels

The Heart and Cardiovascular Function

The Lymphatic System and Immunity

The Respiratory System

The Digestive System

Metabolism and Energetics

The Urinary System

Fluid, Electrolyte, and Acid-Base Balance

The Reproductive System

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