An Embryology Quiz
1: Dual Fertilization
What happens in the rare instance that an egg becomes fertilized by two sperm, one sperm having an X and the other a Y sex chromosome?
a - An embryo can not survive with two blood types.
b - A single blood type and a single sex dominate, the resulting baby having only one blood type
and one sex.
c - The resulting baby has mixed blood type and both sex organs.
d - Dual fertilization can not occur because there can not be a dual-conception event.
e - Can not occur because an egg responds to the first sperm by immediately blocking
all other sperm.
f - The first cell division results in multiple cells with random number of chromosomes,
preventing growth.
Answer
2: Fused Embryos
What happens if two separately fertilized embryos fuse to form a single embryo, and if the two original embryos have different blood type and sex?
a - Embryo fusing can not occur. There can not be any de-conception event.
b - Can't happen, zona pellucida encasing prevents fusing to the wall of the fallopian tubes
and doubly so between embryos.
c - Fused embryos are culled by natural miscarriage. An embryo can not survive with two
blood types.
d - A single blood type and a single sex dominate, the resulting baby having only one blood type
and one sex.
e - The resulting baby has mixed blood type and both sex organs.
Answer
3: Identical Twins
Identical twins result from the splitting of an early embryo into two halves, the halves then both becoming separate embryos. The initial embryo starts as a single egg, fertilized once, and the splitting after a period of growth is in a sense a delayed conception event without fertilization. On average, how delayed is this event?
a - One to two hours after fertilization
b - About a day after fertilization
c - Three or four days after fertilization
d - Five to ten days after fertilization
4: Siamese Twins
Siamese twins are a form of identical twins, the result of splitting happening too late for complete separation. How late is this? What is the time delay after fertilization before which normal identical twins occur and after which the twins are co-joined?
a - Four days
b - Seven days
c - Ten days
d - Fifteen days
5: Laboratory Multiple Splitting
Embryos are now commonly divided in two when using in-vitro fertilization to enhance fertility. This increases the number of scarce embryos available for implantation. So a multi-celled human embryo could be totally split apart in an attempt to see if each cell can grow separately on its own and thereby creating many embryos from one. Has this been tried, and if so at what stage and how successfully?
a - Only splitting in half has been achieved experimentally, no more than the natural process
of identical twins.
b - Only splitting in thirds has been achieved experimentally, like the extremely rare natural
event of triple identical twins.
c - A four celled morula has been split to form four separate embryos with high survival rate.
d - An eight celled morula has been split to form eight separate embryos with high survival rate.
6: High Multiple Births
What is the maximum number of babies that can be born from a single pregnancy without high risk of deformity?
a - 3
b - 4
c - 5
c - 6
d - 7
7: Sex Stem Cells
Men and women both produce a lot of sperm or eggs during their lifetime. Do they achieve this using stem cells, cells that when dividing split off an egg or sperm plus another stem cell to perpetuate the process?
a - Both men and women have sex stem cells.
b - Only men have sex stem cells. Women are born with an ample supply of pre-egg cells
and can not form additional ones after puberty.
c - Only women have sex stem cells. Men are born with an ample supply of pre-sperm cells
and can not form additional ones after puberty.
d - Neither men nor women use sex stem cells. They are both born with an ample supply of
pre-sperm or pre-egg cells.
8: Egg Production
How many eggs does a women produce in a lifetime?
a - Many tens, a few times more than the number of children she might be able to bear
b - Many hundreds
c - Many thousands
d - Many tens of thousands
9: Sperm Production
How many sperm does a man produce in a lifetime?
a - Many thousands
b - Many millions
c - Many billions
d - Many trillions
10: Abortion Prohibition
When did the Catholic Church ban abortion from the time of fertilization?
a - From the time of Saint Augustine and Bishop Theodorus
b - Between 1700 and 1750
c - Between 1750 and 1800
d - Between 1800 and 1850
e - Between 1850 and 1900
f - Between 1900 and 1925
10: Genetic Inheritance
When did scientists first speculated that the union of sperm and egg nuclei might create the genetic inheritance of the future individual?
a - Between 1700 and 1750
b - Between 1750 and 1800
c - Between 1800 and 1850
d - Between 1850 and 1900
e - Between 1900 and 1925
12-15: Oral Contraceptives
How do female hormone oral contraceptives work? Distinguish between the standard birth control pills taken daily with a monthly pause to accommodate menstruation and those taken every day without interruption and preventing monthly periods.
|
| pill
| a
induces
abortion
| b
prevents
implantation
| c
prevents
fertilization
| d
prevents
ovulation
| e
prevents
egg formation
|
| 12
| daily, with period
| y/n
| y/n
| y/n
| y/n
| y/n
|
| 13
| daily, no period
| y/n
| y/n
| y/n
| y/n
| y/n
|
| 14
| Plan-B
| y/n
| y/n
| y/n
| y/n
| y/n
|
| 15
| RU-486
| y/n
| y/n
| y/n
| y/n
| y/n
|
16: Catholic Opposition to Birth Control
What is the basis of the Catholic Church's opposition to birth control?
a - There should never be an abortion or taking of a potential human life even indirectly by birth control.
b - All sex is sinful if not natural in marriage for the purpose of procreation.
c - Carry over of opposition to perverse Greco-Roman sexual practices.
d - Children are punished for the sins of their parents.
e - Scripture such as the Garden of Eden story.
17: Miscarriage and Embryo Attrition
Fetuses sometimes naturally abort. How common is this this type of event, how early does it occur, and for what reasons?
a - From conception on the beginning of life is normally a smooth continuum, with natural miscarriage
occurring only rarely after the fetus is forming and is turning out to be seriously defective.
The overall loss rate is on the order of one in several hundred.
b - The earliest natural attrition occurs because of occasional failure to implant or because of
deficiencies in the embryo at the time of implantation.
c - Natural attrition occurs from the time of fertilization and is highest for new embryos,
the over-all failure rate being more than half.
d - Natural attrition occurs from the time of fertilization and is due about half the time
to egg deficiencies at the time of ovulation, making many eggs predestined to fail
after fertilization
18: Birth Defects
What fraction of babies are either stillborn or born so deformed that they can not survive more than a day or two?
a - About one in 100,000
b - About one in 10,000
c - About one in 1000
d - About one in 100
19: Embryo Adoption
Embryo adoption is the process of a woman's choosing to start her pregnancy by using a frozen preserved embryo that the genetic parents do not want and that would otherwise be discarded. The procedure involves thawing and implantation of more than one embryo to assure success, but not so many as to risk high multiple pregnancy. What is the overall success rate including losses during thawing, implantation and gestation?
a - About one in 15
b - About one in 10
c - About one in 5
d - About one in 2
20: Downs
Forty year old women are 100 times more likely to have babies with Down syndrome than 20 year old women. Why?
a - Ability to adequately supply nutrients through the placenta decreases with age.
b - Older ovaries cause errors in chromosome count during the final month of egg development
before ovulation.
c - Pre-egg cell chromosomes become damaged with time.
d - Fibers to pull apart egg chromosomes become damaged with time.
21: Downs Chromosomes
Down syndrome is a form of trisomy with one of the chromosomes occurring in triplicate rather than duplicate. Which chromosome is involved?
a - 11
b - 13
c - 18
d - 21
e - 23
f - 26
22: Downs Prevention
Modern ultrasound and amniotic genetic screening can detect Down syndrome in the first trimester 98 % of the time with few false positives. Final conclusive confirmation requires inserting a needle into the womb that causes abortion about 1 % of the time. What percentage of Downs is now prevented by the mother choosing not to carry to term?
a - 10 - 20.
b - 20 - 40.
c - 40 - 60
d - 60 - 80
e - 80 - 90
23: First Response
When is a human fetus first able to respond to touch?
a - By two months
b - By three months
c - By four months
d - By five months
e - By six months
24: Fetal Eye Opening
When can fetal eye opening and rubbing first be seen in the womb with ultrasound?
a - By two months
b - By three months
c - By four months
d - By five months
e - By six months
25: Egg Lifetime
How long does a human egg live after release from the ovary if not fertilized?
a - One day
b - Two days
c - Two days plus several hours, but can't be fertilize during those first several hours
d - About three days, but can't be fertilized during the first several hours
26: Sperm Lifetime
How long does a human sperm live after activation if it does not fertilize an egg?
a - One day
b - Two days
c - Two days plus several hours, but not able to fertilize an egg during those first several hours
d - About three days, but not able to fertilize an egg during the first several hours
27: Fallopian Tube Traversal
What fraction of sperm make it to the top of a fallopian tube?
a - One in ten
b - One in a hundred
c - One in a thousand
d - One in a million
28: Ectopic Pregnancy
Why does smoking double the risk of tubal pregnancy?
a - It constricts the fallopian tubes making it difficult for embryos to pass down without implanting.
b - It degrades the zona pellucida, the non-sticky membrane around and protecting the early embryo.
c - It damages cilia in the fallopian tubes.
29: Egg Chromosome Count
How many DNA strands does a human egg have before it is fertilized?
a - 13
b - 23
c - 2x13 = 26
d - 2x23 = 46
30: Fertilization Time
From the time of first contact, how long does it take for a sperm to fertilize a human egg?
a - A few seconds for the egg to dissolve through the egg cell wall
b - About thirty seconds.
c - About thirty minutes
d - Several hours
e - Ten hours
31: Fetal Stem Cell Determination
The developing multi-celled embryo is called a morula through to the 64 cell stage at which point it expands into a hollow ball called the blastocyst. At the 32 cell stage the cells are all initially the same and omnipotent, but 28 or 29 of the cells will lead to outer cells of the blastocyst and then eventually placenta, and only three or four of the 32 cells become the inner mass of pluripotent stem cells that grow into the actual fetus. What determines the distinction in the 32-cell morula between which cells will and will not develop into the future human being?
a - Chance
b - Proximity to the uterine wall at the time of implantation
c - The morula cells are not all the same. Fetal development is relative to an axis. In the embryo
this axis maintains the distinction from the very beginning of which cells will lead to the
future human being.
32: Research Stem Cell Lines
Which of the following have been used as sources for research stem cell lines?
a - Preserved embryos that would otherwise have been discarded
b - The blastocyst inner cell mass using a culture medium of cytoplasm taken from freshly
released unfertilized eggs
c - Adult skin cells adapted in a process reversing embryo growth to turn off specialization
of gene expression
d - Adult skin cells with cytoplasm replaced with that from freshly released unfertilized eggs
33: Cloning
Has cloning been achieved in humans - the process of taking the nucleus from an adult cell and placing it in an unfertilized egg from which the original nucleus has been removed, and then placing this composite cell, unfertilized into the womb.?
a - No. It is illegal and untried.
b - No. It was tried but failed.
c - Yes, but embryo growth was stopped after several cell divisions.
d - Yes, but the person born has been keep private and secret.
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