Deck 43: Animal Development

Question 1

Human embryos differ from bird embryos in that

A) bird embryos undergo metamorphosis to become sexually mature adults.
B) human embryos have no yolk sac.
C) bird embryos have an extra membrane, the allantois, that is not found in human embryos.
D) human embryos have a yolk sac, but it contains very little yolk.
E) human embryos do not undergo cleavage.

Answer 1

D

Question 2

The nervous system forms from the

A) ectoderm.
B) mesoderm.
C) chorion.
D) yolk.
E) endoderm.

Answer 2

A

Question 3

During the embryonic stage, a hollow ball of cells is known as a

A) gastrula.
B) larva.
C) morula.
D) chorion.
E) blastula.

Answer 3

E

Question 4

As a morula, the embryo consists of

A) a cluster of cells that are much larger than normal cells.
B) cells that have different DNA content.
C) three differentiated layers of cells.
D) a hollow ball of cells.
E) a solid mass of cells, each the size of the zygote.

Question 5

In a reptile egg, which membrane is analogous to a lung?

A) Yolk sac
B) Blastocyst
C) Allantois
D) Chorion
E) Amnion

Question 6

In a bird egg, the provides the watery environment in which the embryo develops.

A) blastocyst
B) chorion
C) yolk sac
D) allantois
E) amnion

Question 7

One characteristic of animal development is the specialization in both structure and function that cells undergo. This is called

A) indirect development.
B) direct development.
C) internal development.
D) placental development.
E) differentiation.

Question 8

When a researcher transplanted the nucleus of an intestinal cell from a tadpole into an egg cell whose nucleus had been destroyed, the egg developed into a normal frog. This illustrates that

A) scientists can clone a human by putting one of his or her nuclei into an egg cell.
B) each cell of an organism has all the genes needed for development.
C) a nucleus that is removed from its normal location is influenced by adjoining cells.
D) the homeobox genes in a transplanted nucleus undergo mutation.
E) genes are gained during the process of differentiation.

Question 9

Which of the following is the result of gastrulation?

A) A three- layered embryo
B) The formation of organs
C) A blastula
D) A hollow ball of cells
E) A zygote

Question 10

If the formation of the endoderm does not take place in an embryo, yet the embryo, for whatever reason, continues to develop, which of the following structures will NOT develop?

A) Stomach
B) Skin
C) Heart
D) Kidneys
E) Nervous system

Question 11

Which germ layer forms the pancreas?

A) Mesoderm
B) Epidermis
C) Endodermis
D) Ectoderm
E) Endoderm

Question 12

In placental organisms, the of the embryo merges with the endometrial lining of the uterus to form the placenta.

A) amnion
B) chorion
C) blastopore
D) allantois
E) yolk sac

Question 13

Birds hatch out of their eggs looking like small versions of the adult. This is an example of

A) external development.
B) internal development.
C) genetic dwarfism.
D) indirect development.
E) direct development.

Question 14

The embryo of a undergoes direct development.

A) snake
B) lobster
C) frog
D) dragonfly
E) butterfly

Question 15

Early animal embryos are composed of stem cells, unspecialized cells that are capable of dividing and renewing themselves for long periods. If a stem cell divides by mitosis so that one cell eventually becomes part of the brain and the other cell becomes part of a salivary gland, the cells have

A) lost genes.
B) differentiated.
C) diffused.
D) taken up genes from surrounding cells.
E) increased their genetic variability.

Question 16

Which extraembryonic membrane lies immediately beneath the shell of a reptile embryo?

A) Allantois
B) Chorion
C) Amnion
D) Placenta
E) Yolk sac

Question 17

What is differentiation?

A) The process in which different organ systems become specialized
B) The process in which different cells develop into different cell types
C) The process in which different tissues specialize into specific organs
D) The process in which different organs specialize in function

Question 18

The cells that line the inside of the blastopore become the

A) digestive tract.
B) skin.
C) skeleton.
D) muscles.
E) nervous system.

Question 19

is the developmental event that results in the formation of a primitive gut and the three tissue layers.

A) Metamorphosis
B) Gastrulation
C) Blastulation
D) Induction
E) Cleavage

Question 20

The metamorphosis of a caterpillar into a butterfly is an example of

A) indirect development.
B) placental development.
C) direct development.
D) internal development.
E) external development.

Question 21

In the 1920s, two German embryologists, Hans Spemann and Hilde Mangold, demonstrated that a small patch of cells, called the dorsal lip of the blastopore, would

A) become the neural tube.
B) form the chorion.
C) become the digestive tract.
D) induce the surrounding cells to differentiate.
E) lack the genes necessary to develop the embryo.

Question 22

During mammalian development, a

A) morula becomes gastrula.
B) gastrula becomes a morula.
C) zygote becomes a blastula.
D) blastula becomes a zygote.
E) morula becomes a blastula.

Question 23

At what stage does a human embryo implant in the uterus?

A) Morula
B) Blastocyst
C) Gastrula
D) Fetal
E) Embryonic disk

Question 24

At which stage is the human embryo most susceptible to toxic substances?

A) During organogenesis
B) Just before birth
C) During the last trimester
D) During cleavage
E) During the fourth and fifth months

Question 25

A human embryo is known as a fetus after weeks.

A) 12
B) 4
C) 8
D) 16
E) 2

Question 26

What will occur if a morula divides into three masses of cells?

A) The resulting embryos will develop severe birth defects due to missing genes.
B) Normal identical triplets will be born.
C) Three distinctly different embryos will develop, depending on which homeoboxes went with which mass of cells.
D) The resulting embryos will die.
E) The resulting embryos will develop, but they may be missing some organs based on which germ layers were transferred with each section.

Question 27

Based on experiments with amphibian embryos, Spemann and Mangold found that

A) transplanted cells always died.
B) transplanted cells always formed a whole new embryo.
C) in most cases, transplanted donor cells assumed the developmental fate of the area to which they were transplanted in the host.
D) transplanted cells completely undifferentiated into random masses of tissue.
E) donor cells maintained their original differentiation no matter where in the host they were transplanted.

Question 28

In humans, implantation occurs

A) when the embryo is a gastrula.
B) after the formation of the neural tube.
C) just prior to fertilization.
D) when the zygote is a blastocyst.
E) immediately after fertilization.

Question 29

Induction refers to

A) the formation of the nervous system.
B) the migration of cells to form the gastrula.
C) the formation of the mesoderm layer in a gastrula.
D) chemical messengers from one embryonic cell influencing the development of other cells.
E) hormones from the mother's blood altering the development of the embryo.

Question 30

Cells differentiate during development because

A) genes respond only to influences outside the mother's body.
B) in each cell only some of the genes are expressed.
C) each cell contains only a portion of the genes.
D) chemicals in the sperm cytoplasm determine which cells develop.

Question 31

The birth defect spina bifida results in part of the spinal cord lying outside of the body. This defect is due to abnormal development of the

A) placenta.
B) neural tube.
C) gill grooves.
D) allantois.
E) embryonic disk.

Question 32

The umbilical cord of a mammal connects the

A) amnion and the chorion.
B) fetus and the placenta.
C) embryo and the amnion.
D) yolk sac and the allantois.
E) maternal and fetal bloodstreams.

Question 33

In humans, fertilization occurs in the

A) testes.
B) vagina.
C) uterus.
D) ovary.
E) uterine tube.

Question 34

The proteins that bind to the DNA near regions where gene transcription begins are called

A) promoter genes.
B) transcription factors.
C) the gray crescent.
D) mRNA.
E) homeobox genes.

Question 35

What makes the cells of a developing embryo differentiate into various types of cells?

A) They have different genes.
B) Different genes are activated.
C) The DNA of their mitochondria is different.
D) Special genes in the cytoplasm cause this differentiation.
E) Once certain genes of a cell have caused it to differentiate, the other genes are lost.

Question 36

The structure produced by cleavage of a human zygote is called a(n)

A) embryonic disk.
B) blastopore.
C) blastocyst.
D) chorion.
E) gastrula.

Question 37

Your biceps muscle is derived from the

A) ectoderm.
B) amnion.
C) mesoderm.
D) endoderm.
E) blastopore.

Question 38

Transplanting embryonic eye tissue into the back of a developing tadpole will cause a lens to grow on the back of the tadpole. This is an example of

A) programmed cell death.
B) metamorphosis.
C) cleavage.
D) induction.
E) gastrulation.

Question 39

After induction occurs, the

A) transcription of all genes stops.
B) cells have different genes.
C) fate of each cell is permanently fixed.
D) DNA of the mitochondria differentiates into new genes.

Question 40

A developing human is considered an embryo after _ weeks.

A) 8
B) 2
C) 12
D) 4
E) 16

Question 41

The last 7 months of pregnancy are devoted to

A) growth.
B) formation of major organs.
C) organization of organs into organ systems.
D) formation of tissue layers.
E) formation of the brain.

Question 42

The process through which a human embryo develops into an adult is called metamorphosis.

Question 43

is the medication given to combat morning sickness that caused deformed and missing limbs in infants in the late 1950s and early 1960s.

A) Alcohol
B) Nicotine
C) Thalidomide
D) Rubella
E) Accutane®

Question 44

In indirect development, the embryo hatches into a sexually immature stage called a larva.

Question 45

The cells of an aging animal function less efficiently because

A) organelles and cellular components decline.
B) cells can no longer mitotically divide.
C) cell metabolism is slower.
D) protein synthesis ceases.
E) damaged DNA cannot be repaired.

Question 46

Suppose a pregnant woman took a drug that causes incomplete brain formation during fetal development. When must the woman have taken the drug for this effect to occur?

A) During labor
B) In the first month of development
C) Between the second and third months of development
D) Between the seventh and eighth months of development
E) Between the fifth and sixth months of development

Question 47

Stem cells developed by inserting genes that regulate the transcription of specific genes into cells from an adult are cells.

A) embryonic stem
B) chorionic villi
C) embryonic disk
D) gastrula
E) induced pluripotent stem

Question 48

A human embryologist examines a 3- week- old embryo and notices that it has not developed a notochord. If the embryo survives, it will lack

A) a stomach and a pancreas.
B) skin and blood vessels.
C) a brain and a spinal cord.
D) a heart and lungs.

Question 49

Most fetuses can survive outside the womb after a minimum of weeks.

A) 32
B) 38
C) 20
D) 15
E) 45

Question 50

Which of these hormones stimulates the production of milk?

A) Oxytocin
B) Prolactin
C) Estrogen
D) Progesterone
E) Colostrum

Question 51

All cells in an animal, with the exception of gametes, are genetically identical.

Question 52

The placental blood vessels

A) manufacture hormones that slow the growth of the embryo, preventing it from outgrowing the uterus.
B) prevent all microbes and toxins from crossing from mother to child.
C) allow for the exchange of wastes and nutrients but keep the maternal and fetal circulations separate.
D) mix maternal blood and fetal blood.
E) draw oxygen from the fetal blood and pass it to the mother.

Question 53

In species with direct development, fewer offspring are produced, but a higher proportion survives to adulthood.

Question 54

Which of the following occurs in the placenta?

A) Hormones are absorbed to prevent them from influencing the developing fetus.
B) All substances in maternal blood that may be harmful to the fetus are prevented from moving across the walls of the villi.
C) Fetal blood and maternal blood mix.
D) Eroding blood vessels in the endometrium bathe chorionic villi in pools of maternal blood.
E) The amnion and the chorion grow into the endometrium.

Question 55

The outer cell layer of the blastocyst becomes the , which forms the embryonic portion of the placenta.

A) primitive streak
B) chorion
C) inner cell mass
D) yolk sac
E) embryonic disk

Question 56

Most microbes cannot gain access to the fetus. However, _, which causes syphilis in adults, can cross the placenta and attack the fetus, causing stillbirths and mental retardation.

A) rubella
B) HIV
C) Treponema pallidum
D) Listeria
E) Staphylococcus

Question 57

Prior to birth, stretching of the cervix by the baby's head stimulates the release of

A) oxytocin.
B) progesterone.
C) estrogen.
D) colostrum.
E) prolactin.

Question 58

As early as the month, as the brain and spinal cord grow, the fetus can demonstrate movement and respond to stimuli.

A) fifth
B) third
C) sixth
D) fourth
E) second

Question 59

diffuse(s) from fetal blood to maternal blood in the placenta.

A) Wastes
B) Oxygen
C) Nutrients
D) Infectious organisms
E) Alcohol

Question 60

In animals that undergo indirect development, the newborn has a similar body structure to that of the adult.

Question 61

The extraembryonic membrane that sends blood vessels into the endometrium is the chorion.

Question 62

Cellular differentiation depends on which genes are turned on or expressed in the cell.

Question 63

The small, hollow ball of cells in early development is the zygote.

Question 64

A morula is a solid ball of undifferentiated cells.

Question 65

The developing fetus secretes chorionic gonadotropin only during the first 2 weeks of pregnancy.

Question 66

In blastulas, if cells from an area that would normally become skin are transplanted into an area that would become the nervous system, the transplanted cells will form structures of the nervous system.

Question 67

Maternal blood and fetal blood are mixed in the placenta.

Question 68

The blastopore forms during gastrulation.

Question 69

Longevity in animals appears to be most related to their cells' ability to repair damage to their own DNA.

Question 70

Mitotic cell divisions of the zygote are collectively called cleavage.

Question 71

The amnion forms the watery environment that encloses the embryo.

Question 72

The nervous system develops from the endoderm.

Question 73

At 10 weeks, the blastocyst becomes an embryo.

Question 74

The most rapid differentiation in an embryo occurs during the first 2 months of pregnancy.

Question 75

Amphibians, reptiles, and mammals pass through embryonic stages in which they have tails and webbed fingers and toes.

Question 76

The placenta prevents pathogenic microbes such as HIV and chemicals such as alcohol from reaching the baby's bloodstream.

Question 77

Yolk sacs are found only in animals with shelled eggs.

Question 78

The mesoderm develops into the dermis of the skin and the skeleton.

Question 79

The blastocyst implants in the endometrium about 7 days after fertilization.

Question 80

Homeobox genes determine the overall shape of the body and the location of its parts.