Deck 21: Development and Aging

Question 1

What marks the end of the pre-embryonic period and the beginning of the embryonic period?

A) implantation
B) the formation of the ectoderm and endoderm in the embryonic disk
C) the formation of the morula
D) the formation of the blastocyst
E) the formation of pharyngeal arches

Answer 1

A

Question 2

The placenta forms from embryonic tissue and

A) bone marrow
B) amniotic fluid
C) the embryonic disk
D) endometrium
E) the yolk sac

Answer 2

D

Question 3

Fertilization is generally considered complete when the

A) zygote enters the uterus
B) sperm reaches the zona pellucida
C) ovulation is inhibited
D) placenta begins to form
E) haploid sperm units with the mature ovum

Answer 3

E

Question 4

In humans, fertilization usually occurs ________ after intercourse, if an egg is present.

A) 1-2 hours
B) 3-6 days
C) 6-24 hours
D) 7-10 days
E) 24-48 hours

Question 5

The zona pellucida and corona radiata are associated with which one of the following?

A) human egg
B) uterine lining
C) midpiece of the human sperm
D) cilia of the oviducts
E) vaginal wall

Question 6

While normally one secondary oocyte ruptures from an ovarian follicle at ovulation, what will be the result if two are released and both are fertilized?

A) identical twins
B) single birth because only one secondary oocyte can be fertilized
C) single birth because even though both may be fertilized, only one will be able to complete development
D) fraternal twins

Question 7

A zygote forms when

A) the nucleus from the sperm fuses with the egg nucleus
B) the sperm penetrates the zona pellucida
C) the blastocyst begins to form
D) the acrosomal cap is ruptured
E) meiosis II in the secondary oocyte initiates

Question 8

Most sperm cells die in the vagina when entering the female's body because

A) the sperm cannot pass through the mucus
B) the female's reproductive tract is protected by digestive enzymes
C) of the low pH of the vagina
D) the sperm cells have not yet been activated to swim
E) macrophages from the female's immune system destroy all non-self cells

Question 9

The blastocyst begins to form a second hollow cavity that will eventually become the

A) placenta
B) fundus
C) amniotic cavity
D) embryonic disk
E) embryo

Question 10

To penetrate the zona pellucida of the ovum, the sperm

A) uses the swimming action of the flagellum to move inside the egg
B) releases digestive enzymes from the acrosomal cap
C) releases a hormone that signals the egg to dissolve the thick coating
D) passes down a channel in the protective layer to reach the egg membrane
E) stimulates opening of ion channels along the egg membrane by releasing sodium ions from the acrosomal cap

Question 11

The process by which the blastocyst becomes buried within the endometrial lining of the uterus is called

A) fertilization
B) implantation
C) morphogenesis
D) differentiation
E) embryonic development

Question 12

The process by which an embryo undergoes rapid changes in form and shape is called

A) cleavage
B) fertilization
C) morphogenesis
D) implantation
E) differentiation

Question 13

The first four days of human embryonic development occur in the

A) uterus
B) vagina
C) cervix
D) oviduct
E) ovary

Question 14

During the development following fertilization, the morula becomes a hollow ball of cells called the

A) conceptus
B) fetus
C) germ layer
D) blastocyst
E) secondary morula

Question 15

When a sperm cell enters a secondary oocyte, what event in the oocyte is immediately triggered?

A) cytokinesis
B) mitosis
C) meiosis I
D) meiosis II
E) ovulation

Question 16

Mesoderm gives rise to

A) ectoderm
B) epidermis and dermis
C) muscle and connective tissues
D) the nervous system
E) liver and pancreas

Question 17

The figure above shows a human sperm. Which part of the sperm contains the most mitochondria for generating ATP?

A) A
B) B
C) C
D) A and B
E) B and C

Question 18

All of the following processes are associated with embryonic development EXCEPT which one?

A) cleavage
B) meiosis
C) morphogenesis
D) differentiation
E) growth

Question 19

There are a series of cell divisions that produce no cell growth during the first four days following fertilization. This process is referred to as

A) cleavage
B) conceptus
C) morphogenesis
D) implantation
E) differentiation

Question 20

The blood vessels of the umbilical cord are derived from which one of the following structures?

A) allantois
B) chorion
C) embryonic disk
D) amnion
E) yolk sac

Question 21

Which organ system is not functional until birth and must become fully functional immediately?

A) excretory system (kidneys)
B) respiratory system
C) cardiovascular system
D) muscular system
E) skeletal system

Question 22

Oxytocin from the mother's pituitary gland targets what organ to begin contractions?

A) oviduct
B) vagina
C) hypothalamus
D) uterus
E) fimbriae

Question 23

Labor is triggered when which one of the following fetal organs or systems is mature?

A) pituitary gland
B) digestive system
C) heart
D) lungs
E) adrenal gland

Question 24

In the prenatal diagnostic technique amniocentesis,

A) a needle is inserted into the umbilical cord to collect fetal blood for screening
B) a thin, flexible tube connected to a needle is inserted through the vagina and into the uterus to collect a tissue sample
C) fetal blood is collected directly from the chorionic villi near the cervix
D) a needle is inserted through the abdominal wall to collect amniotic fluid containing fetal cells
E) the procedure cannot be performed after the fifteenth week of gestation

Question 25

Maturation of the reproductive organs and the reproductive response is called

A) adolescence
B) longevity
C) puberty
D) morula
E) menopause

Question 26

During the first day or so after birth, the breasts produce a watery milk called

A) prostaglandins
B) amniotic fluid
C) lactose
D) colostrum
E) allantois

Question 27

The stages of labor, in order, include

A) dilation, contraction, and afterbirth
B) contraction, dilation, and afterbirth
C) dilation, contraction, and expulsion
D) dilation, expulsion, and afterbirth
E) amniotic rupture, contraction, and expulsion

Question 28

Which one of the following organs is not fully developed in a fetus and is therefore bypassed by the ductus arteriosus?

A) liver
B) pancreas
C) heart
D) lungs
E) bladder

Question 29

All of the following can pass through a healthy placenta EXCEPT which one?

A) water
B) nutrients
C) oxygen
D) some antibodies
E) blood cells

Question 30

Research on the aging process shows that wounds of the elderly heal more slowly and that they are more susceptible to disease. These are problems associated with an aging ________ system.

A) respiratory
B) immune
C) integumentary
D) digestive
E) endocrine

Question 31

Which one of the following statements about gender determination is TRUE?

A) The male gender is determined by the presence of only one X chromosome.
B) The male gender is determined by the presence of a Y chromosome.
C) The hormones estrogen and progesterone are key players in the development of internal and external female genitalia.
D) The development of male genitalia is the "default" condition in the absence of estrogen.
E) The development of female genitalia is activated by the presence of anti-Mullerian hormone.

Question 32

With the exception of cancer cells, most cells divide approximately ________ times before they stop reproducing.

A) 2-4
B) 10-12
C) 20-25
D) 50-90
E) 100-200

Question 33

During puberty, the secretion of GnRH causes the secretion of ________, which in turn stimulate(s) the production of sex hormones.

A) LH and FSH
B) oxytocin and prolactin
C) insulin
D) growth hormone
E) oxytocin and growth hormone

Question 34

The number of oxytocin receptors present in the uterus increases due to the action of

A) oxytocin
B) estrogen
C) LH
D) prostaglandins
E) FSH

Question 35

Which cardiovascular structures in the fetus shunt blood away from the fetal lungs?

A) foramen ovale and ductus arteriosus
B) foramen magnum and ductus venosus
C) foramen ovale and ductus venosus
D) umbilical artery and umbilical vein
E) umbilical artery and ductus venosus

Question 36

The muscles and nervous system of the fetus become mature enough for movement to occur by the ________ month of development.

A) fifth
B) first
C) eighth
D) third
E) seventh

Question 37

Which one of the following embryonic features is the forerunner of the brain and spinal cord?

A) pharyngeal arches
B) somites
C) yolk sac
D) neural groove
E) chorionic villi

Question 38

The placenta is detached from the uterus during which one of the following stages of labor?

A) placental
B) dilation
C) secretory
D) expulsion
E) afterbirth

Question 39

Why is taking the first breath hard work for the newborn?

A) The lungs are not elastic.
B) The intercostal muscles are not mature enough.
C) The diaphragm is inflexible.
D) The surface tension within the alveoli is very high.
E) The respiratory center in the medulla is not yet mature.

Question 40

The figure above shows the development of the human embryo during days 19-24. Which of the following organs forms from the ectodermal folds of the embryo?

A) stomach and small intestine
B) kidneys, ureters, and bladder
C) heart
D) liver
E) brain and spinal cord

Question 41

Surgical delivery of a baby is called a cesarean delivery.

Question 42

Prior to the union of the chromosomes of the egg and sperm, meiosis II is completed by the ovum.

Question 43

Many sperm entering the vagina are killed by the acidic secretions of the female reproductive tract.

Question 44

The cell formed by the union of egg and sperm during fertilization is the ________.

Question 45

The chances of "aging well" can be increased through a healthy diet and regular exercise.

Question 46

During the first four days of development following fertilization, cells of the embryo undergo rapid cleavage, but the size of the embryo remains the same.

Question 47

Fertilization is completed when the sperm nucleus fuses with the ________.

Question 48

As an adult human ages, the blood vessels lose their elasticity, and blood pressure drops as dilation occurs.

Question 49

In the fetus, the ductus arteriosus shunts blood from the pulmonary artery directly to the lung.

Question 50

Which one of the following is TRUE regarding an aging nervous system?

A) Neurons continue to reproduce to replace damaged neurons, but at a slower pace.
B) The brain increases slightly in size.
C) Lenses of the eyes stiffen, making it more difficult to focus.
D) Balance and motor skills are affected; the senses of smell and taste are not affected.
E) The number of connections between neurons of the brain decrease.

Question 51

During embryonic development, the second cavity that forms in the blastocyst becomes filled with amniotic fluid.

Question 52

The duration of a person's life is referred to as

A) aging
B) longevity
C) eon
D) gestation
E) puberty

Question 53

Pregnancy occurs when the morula stage implants in the uterus.

Question 54

For sperm to be able to penetrate the zona pellucida of the egg, enzymes are released from the ________.

Question 55

Insertion of a thin tube through the vagina into the uterus to sample fetal tissue is called ________.

Question 56

As the onset of labor approaches, estrogen is released by the placenta, and increases the number of oxytocin receptors.

Question 57

Following fertilization, if a ball of embryonic cells splits into two masses before differentiation has begun, ________ twins result.

Question 58

One hypothesis for why we age, or at least why our cells age, is that every time that mitosis occurs, ________ at the ends of chromosomes shorten, and eventually the cell runs out of these units at the ends of chromosomes.

Question 59

If you have ever had a chance to witness a child birth, then you know it is an amazing event. However, even after the baby has been removed from the mother, her work is not complete in terms of labor. Why?

Question 60

If an embryo implants in an organ other than the uterus, the pregnancy is said to be ________.

Question 61

The formation of the ________ cavity and the differentiation of the embryonic disk into ectoderm and endoderm occurs at the end of the pre-embryonic period of development.

Question 62

The entire duration of a person's life is referred to as ________.

Question 63

Labor is a highly coordinated event that requires the participation of numerous signaling molecules. Discuss how hormones help coordinate the events of labor to ensure that a child is delivered quickly.

Question 64

The spontaneous ending of a pregnancy that results in the premature expulsion of the embryo is termed a(n) ________.

Question 65

During labor, full dilation of the cervix signifies the end of the ________ stage.

Question 66

Adolescence is marked by maturation of the reproductive organs and the human sexual response, an event known as ________.

Question 67

Ejection of milk from the breasts is caused by the hormone ________.

Question 68

For fertilization to occur in humans, the sperm cells have a long journey to complete before reaching an egg. If a sperm reaches an egg, fertilization is still not complete. What events must happen for fertilization to be complete?

Question 69

The extra-embryonic membrane known as the ________ is the source of germ cells that eventually develop into gametes.