Question 1

Gastrulation produces ____.&#10;A) &#8203;hollow balls of cells&#10;B) &#8203;embryos with three primary tissue layers&#10;C) &#8203;solid balls of cells&#10;D) &#8203;specific organs&#10;E) &#8203;dead tissue

Accepted Answer

Gastrulation is the process in early embryonic development that leads to the formation of three primary tissue layers - ectoderm, mesoderm, and endoderm. These layers give rise to all the tissues and organs in the body. Choice A is not correct as hollow balls of cells are formed during the blastula stage preceding gastrulation. Choice C and E are incorrect as gastrulation produces structures that are far from being either solid balls of cells or dead tissue. Choice D is incorrect as specific organs arise much later in development, from the three primary germ layers formed during gastrulation.

Question 2

Which stage of development carves up the zygote's cytoplasm?&#10;A) &#8203;gamete formation&#10;B) &#8203;cleavage&#10;C) &#8203;gastrulation&#10;D) &#8203;organ formation&#10;E) &#8203;tissue specialization

Accepted Answer

During cleavage, the zygote undergoes rapid cell divisions without growth, resulting in the formation of smaller and smaller cells called blastomeres. Cleavage also involves the division of the zygote's cytoplasm to distribute the genetic material to each blastomere.

Question 3

Which embryonic tissue is incorrectly associated with its derivative?&#10;A) &#8203;skin; ectoderm&#10;B) &#8203;nervous system; ectoderm&#10;C) &#8203;liver; endoderm&#10;D) &#8203;circulatory system; mesoderm&#10;E) &#8203;brain; mesoderm

Accepted Answer

The brain is derived from the ectoderm, not the mesoderm.

Question 4

The letter &#34;C&#34; in the accompanying figure represents ____.&#10;A) ectoderm&#8203;&#10;B) &#8203;endoderm&#10;C) &#8203;mesoderm&#10;D) &#8203;neural plate&#10;E) &#8203;yolk

Accepted Answer

The letter "C" in the figure above represents mesoderm, which gives rise to muscles, bones, and the circulatory system.

Question 5

&#10;The following questions refer to the figure above illustrating frog development.&#10;In amphibians, a pigmented area called the ____ appears after fertilization.&#10;A) &#8203;gray matter&#10;B) &#8203;gray crescent&#10;C) &#8203;blastomere&#10;D) &#8203;cleavage plane&#10;E) &#8203;gray oocyte

Accepted Answer

The gray crescent is a pigmented area that appears after fertilization in amphibian embryos. This area plays a vital role in determining the embryonic axis and the formation of the dorsal-ventral axis. The other choices (gray matter, blastomere, cleavage plane, and gray oocyte) do not accurately describe the pigmented area that appears in amphibian embryos after fertilization.

Question 6

Four of the following are characteristic of morphogens. Which one is the exception?&#10;A) &#8203;They are long-range signals in pattern formation.&#10;B) &#8203;They are encoded by master genes.&#10;C) &#8203;They affect gene splicing.&#10;D) &#8203;Their concentration decreases with distance from source.&#10;E) &#8203;They affect development.

Accepted Answer

Morphogens do not affect gene splicing. They primarily affect cell differentiation and development through concentration gradients in a developing embryo. The other listed characteristics are true of morphogens.

Question 7

Four of the following can cause birth defects. Which one is the exception?&#10;A) &#8203;tobacco&#10;B) &#8203;alcohol&#10;C) &#8203;poor nutrition&#10;D) &#8203;rubella&#10;E) &#8203;folic acid

Accepted Answer

Folic acid is actually important in preventing birth defects such as neural tube defects. The other options listed can all contribute to birth defects in various ways.

Question 8

Which of the following is the first stage in reproduction and development?&#10;A) &#8203;cleavage&#10;B) &#8203;gamete formation&#10;C) &#8203;gastrula formation&#10;D) &#8203;zygote formation&#10;E) &#8203;blastula formation

Accepted Answer

Gamete formation is the first stage in reproduction and development, as it involves the production of sperm and eggs necessary for fertilization.

Question 9

About half of all miscarriages are caused by ____.&#10;A) &#8203;chromosomal abnormalities&#10;B) &#8203;alcohol use during pregnancy&#10;C) &#8203;cleft palate&#10;D) &#8203;tobacco use during pregnancy&#10;E) &#8203;illegal drug use during pregnancy

Accepted Answer

Chromosomal abnormalities are the most common cause of spontaneous miscarriage, accounting for about 50% of all cases. Factors such as maternal age, exposure to environmental toxins, and certain underlying medical conditions can increase the risk of chromosomal abnormalities in the developing fetus.

Question 10

Select the correct sequence of animal developmental events.&#10;A) &#8203;fertilization &#8594; cleavage &#8594; gastrula &#8594; blastula&#10;B) &#8203;fertilization &#8594; cleavage &#8594; blastula &#8594; gastrula&#10;C) &#8203;fertilization &#8594; blastula &#8594; cleavage &#8594; gastrula&#10;D) &#8203;fertilization &#8594; gastrula &#8594; blastula &#8594; cleavage&#10;E) &#8203;fertilization &#8594; blastula &#8594; gastrula &#8594; cleavage

Accepted Answer

Fertilization is the first step followed by cleavage (the division of the zygote into smaller cells), blastula (the formation of a hollow ball of cells), and gastrula (the formation of three germ layers). This is the correct sequence of animal developmental events.

Question 11

&#10;The following questions refer to the figure above illustrating frog development.&#10;Cleavage is indicated by the letter ____.&#10;A) &#8203;A&#10;B) &#8203;B&#10;C) &#8203;C&#10;D) &#8203;D&#10;E) &#8203;E

Accepted Answer

The answer of   &#10;The following questions refer to...

Question 12

Different cell lineages express different subsets of genes, resulting in _____.&#10;A) &#8203;epigenetics&#10;B) &#8203;selective genetics&#10;C) &#8203;differentiation&#10;D) &#8203;morphogenic&#10;E) &#8203;assimilation

Accepted Answer

The answer of Different cell lineages express different subsets of...

Question 13

&#10;The following questions refer to the figure above illustrating frog development.&#10;Organ formation is occurring at ____.&#10;A) &#8203;A&#10;B) &#8203;B&#10;C) &#8203;C&#10;D) &#8203;D&#10;E) &#8203;E

Accepted Answer

The answer of   &#10;The following questions refer to...

Question 14

Four of the following have radial cleavage patterns. Which one is the exception?&#10;A) &#8203;snails&#10;B) &#8203;salamanders&#10;C) &#8203;earthworms&#10;D) &#8203;sea stars&#10;E) &#8203;mammals

Accepted Answer

The answer of Four of the following have radial cleavage...

Question 15

The process that causes embryonic cells to produce signals that alter the behavior of neighboring cells is known as ____.&#10;A) &#8203;contact inhibition&#10;B) &#8203;ooplasmic localization&#10;C) &#8203;embryonic induction&#10;D) &#8203;pattern formation&#10;E) &#8203;gene splicing

Accepted Answer

The answer of The process that causes embryonic cells to...

Question 16

The bicoid protein of a fruit fly is an example of _____.&#10;A) &#8203;embryonic induction&#10;B) &#8203;epigenetics&#10;C) &#8203;differentiation&#10;D) &#8203;amorphogen&#10;E) &#8203;assimilation

Accepted Answer

The answer of The bicoid protein of a fruit fly...

Question 17

An evolutionary model of animal development indicates that _____.&#10;A) &#8203;differentiation is positional within a zygote&#10;B) &#8203;homeotic genes are not universal among animals&#10;C) &#8203;homeotic genes are found only in fruit flies, where they are responsible for odd placement of appendages&#10;D) &#8203;new genetic lines are produced less by modification than by unique mutation&#10;E) &#8203;somitesform as blocks of genes in cells randomly distributed throughout the body

Accepted Answer

The answer of An evolutionary model of animal development indicates...

Question 18

The letter &#34;A&#34; in the accompanying figure represents ____.&#10;A) &#8203;ectoderm&#10;B) &#8203;endoderm&#10;C) &#8203;mesoderm&#10;D) &#8203;neural plate&#10;E) &#8203;yolk

Accepted Answer

The answer of The letter &#34;A&#34; in the accompanying figure...

Question 19

Without _____, humans might have a tail.&#10;A) &#8203;differentiation&#10;B) epigenetics&#10;C) &#8203;cell migrations&#10;D) &#8203;apoptosis&#10;E) &#8203;the maternal gene effect

Accepted Answer

The answer of Without _____, humans might have a tail.&#10;A)...

Question 20

The zygote goes through ____ to become a(n) ____.&#10;A) &#8203;cleavage; blastula&#10;B) &#8203;cleavage; gastrula&#10;C) &#8203;zygote formation; embryo&#10;D) &#8203;cleavage; egg&#10;E) &#8203;fertilization; blastula

Accepted Answer

The answer of The zygote goes through ____ to become...

Question 21

Labor preceding birth _____.&#10;A) &#8203;is a positive feedback loop&#10;B) &#8203;is a negative feedback loop&#10;C) &#8203;is influenced by prolactin&#10;D) &#8203;proceeds at a regular pace&#10;E) &#8203;stabilizes hormonal balance

Accepted Answer

The answer of Labor preceding birth _____.&#10;A) &#8203;is a positive...

Question 22

The pre-natal period begins with the ____.&#10;A) &#8203;zygote&#10;B) &#8203;blastocyst&#10;C) &#8203;embryo&#10;D) &#8203;fetus&#10;E) &#8203;infant

Accepted Answer

The answer of The pre-natal period begins with the ____.&#10;A)...

Question 23

&#10;Use the figure above showing human embryonic developmental day 14 to answer the following questions.&#10;The human brain is fully functional by the end of the ____.&#10;A) &#8203;first trimester&#10;B) &#8203;third month&#10;C) &#8203;third trimester&#10;D) &#8203;ninth month&#10;E) &#8203;seventh month

Accepted Answer

The answer of   &#10;Use the figure above showing...

Question 24

During days 8 and 9 after fertilization in humans, ____.&#10;A) &#8203;amnion cleavage begins&#10;B) &#8203;a blastocyst forms&#10;C) &#8203;an embryonic disk is formed&#10;D) &#8203;implantation occurs&#10;E) &#8203;gastrulationoccurs

Accepted Answer

The answer of During days 8 and 9 after fertilization...

Question 25

The female hormone that participates in milk production is _____ and the hormone that facilitates delivery is _____.&#10;A) &#8203;prolactin; oxytocin&#10;B) &#8203;prolactin; estrogen&#10;C) &#8203;prolactin; progesterone&#10;D) &#8203;oxytocin; estrogen&#10;E) &#8203;oxytocin; progesterone

Accepted Answer

The answer of The female hormone that participates in milk...

Question 26

Organs form and begin to function during the ____ period.&#10;A) &#8203;embryonic&#10;B) &#8203;amniotic&#10;C) &#8203;fetal&#10;D) &#8203;chorionic&#10;E) &#8203;gastrulation

Accepted Answer

The answer of Organs form and begin to function during...

Question 27

In humans, the term embryo refers to the following period of time: ____.&#10;A) &#8203;from the ninth week after fertilization until birth&#10;B) &#8203;from the eighth week after fertilization until birth&#10;C) &#8203;from fertilization until the ninth week after fertilization&#10;D) &#8203;from 2 to 10 weeks after fertilization&#10;E) &#8203;from 2 to 8 weeks after fertilization

Accepted Answer

The answer of In humans, the term embryo refers to...

Question 28

Which human extraembryonic membrane forms the blood vessels of the umbilical cord?&#10;A) &#8203;amnion&#10;B) &#8203;yolk sac&#10;C) &#8203;chorion&#10;D) &#8203;allantois&#10;E) &#8203;protein coat

Accepted Answer

The answer of Which human extraembryonic membrane forms the blood...

Question 29

Which of the following may contribute to pregnancy problems?&#10;A) &#8203;taking naps&#10;B) &#8203;being active&#10;C) &#8203;being over 30&#10;D) &#8203;having dietary deficiencies&#10;E) &#8203;having limited protein intake

Accepted Answer

The answer of Which of the following may contribute to...

Question 30

Exposure to a teratogen during pregnancy can result in ____.&#10;A) &#8203;decreased risk of miscarriage&#10;B) &#8203;newborns of higher birth weight&#10;C) &#8203;reduced vitamin C levels for the mother-to-be and for her fetus&#10;D) &#8203;fetal facial and cranial deformities&#10;E) &#8203;increased risk of rubella

Accepted Answer

The answer of Exposure to a teratogen during pregnancy can...

Question 31

By the eighth week of human fetal development, ____.&#10;A) &#8203;the embryo does not look human yet&#10;B) &#8203;the neural tube has just begun to differentiate&#10;C) &#8203;upper and lower limbs have formed, but individual fingers and toes have not begun to differentiate&#10;D) &#8203;male or female reproductive structures have not started to form yet&#10;E) &#8203;male or female reproductive structures are forming

Accepted Answer

The answer of By the eighth week of human fetal...

Question 32

&#10;Use the figure above showing human embryonic developmental day 14 to answer the following questions.&#10;The chorionic cavity is indicated by ____.&#10;A) &#8203;A&#10;B) &#8203;B&#10;C) &#8203;C&#10;D) &#8203;D&#10;E) &#8203;E

Accepted Answer

The answer of   &#10;Use the figure above showing...

Question 33

In the placenta, nutrients move from mother to baby by ____.&#10;A) &#8203;activated transport&#10;B) &#8203;the Rh factor&#10;C) &#8203;transport proteins&#10;D) &#8203;simple diffusion&#10;E) &#8203;HCG

Accepted Answer

The answer of In the placenta, nutrients move from mother...

Question 34

Fertilization typically occurs in the ____.&#10;A) &#8203;ovary&#10;B) &#8203;oviduct&#10;C) &#8203;uterus&#10;D) &#8203;cervix&#10;E) &#8203;vagina

Accepted Answer

The answer of Fertilization typically occurs in the ____.&#10;A) &#8203;ovary&#10;B)...

Question 35

During pregnancy, a maternal antibody transported across the placenta to the fetal bloodstream can cause a problem if the mother ____.&#10;A) &#8203;has passed on any teratogens&#10;B) &#8203;and baby have different Rh factors&#10;C) &#8203;is producing HCG&#10;D) &#8203;smokes during pregnancy&#10;E) &#8203;uses alcohol during pregnancy

Accepted Answer

The answer of During pregnancy, a maternal antibody transported across...

Question 36

Adequate intake of ____ by a mother-to-be before and during early pregnancy may reduce the risk of spina bifida and other serious neural tube defects.&#10;A) &#8203;carbohydrates&#10;B) &#8203;folic acid&#10;C) &#8203;calcium&#10;D) &#8203;vitamin C&#10;E) &#8203;sodium

Accepted Answer

The answer of Adequate intake of ____ by a mother-to-be...

Question 37

Human milk contains _____.&#10;A) &#8203;calcium only&#10;B) &#8203;antibodies only&#10;C) &#8203;calcium and protein, but not antibodies&#10;D) &#8203;sugar and calcium, but not protein&#10;E) &#8203;calcium, antibodies, sugar, and protein

Accepted Answer

The answer of Human milk contains _____.&#10;A) &#8203;calcium only&#10;B) &#8203;antibodies...

Question 38

&#10;Use the figure above showing human embryonic developmental day 14 to answer the following questions.&#10;Which of the following structures represents the yolk sac?&#10;A) &#8203;A&#10;B) &#8203;B&#10;C) &#8203;C&#10;D) &#8203;D&#10;E) &#8203;E

Accepted Answer

The answer of   &#10;Use the figure above showing...

Question 39

The hormone ____ is involved in a positive feedback cycle that results in strong uterine contractions during labor.&#10;A) &#8203;estrogen&#10;B) &#8203;oxytocin&#10;C) &#8203;cortisol&#10;D) &#8203;progesterone&#10;E) &#8203;prolactin

Accepted Answer

The answer of The hormone ____ is involved in a...

Question 40

The placenta ____.&#10;A) &#8203;forms from endometrial and extraembryonic tissues&#10;B) &#8203;will cover about one-half of the inner uterine surface at full term&#10;C) &#8203;intermingles fetal blood with maternal blood&#10;D) &#8203;secretes only estrogen to maintain the uterine lining during the second and third trimesters&#10;E) &#8203;secretes only progesterone to maintain the uterine lining during the second and third trimesters

Accepted Answer

The answer of The placenta ____.&#10;A) &#8203;forms from endometrial and...

Question 41