Instructor Manual for Human
Genetics 13th Editon By Ricki
Lewis (All Chapters 1-23,
100% Original Verified, A+
Grade)
All Chapters Arranged
Reverse: 23-1
Part 1: Instructor Manual
Part 2: Answers to selected
Key Concepts Questions
,Part 1: Instructor Manual: Chapter 23-1
Chapter 23 Reproductive Technologies
READINGS
Chapter Opener
Choosing an Embryo
Clinical Connection 23.1
The Case of the Round-Headed Sperm
Bioethics
Removing and Using Gametes After Death
CHAPTER OVERVIEW
Assisted reproductive technologies (ARTs) provide ways for people to
have children who have infertility. Countries vary in the extent of their
regulation of ARTs. In vitro fertilization (IVF) teamed with
preimplantation genetic diagnosis (PGD) screens early embryos for
specific mutations and/or chromosomal abnormalities. Selected
embryos are transferred to the uterus to complete development.
Sequential polar body analysis detects mutations in polar bodies and
uses Mendel’s first law to infer the genotype of the associated oocyte.
ARTs present ethical dilemmas and legal considerations concerning
parental identity. Extra oocytes, fertilized ova, and embryos from ARTs
can be stored indefinitely, donated, discarded, or used in research.
CHAPTER OUTLINE
23.1 Savior Siblings and More
1. Assisted reproductive technologies (ARTs) replace gametes, aid fertilization, or
provide a uterus, to help people with infertility.
2. Preimplantation genetic diagnosis (PGD) was developed to allow families with
known single-gene diseases or chromosomal anomalies to select embryos that do
not have the mutation for transfer to the woman’s uterus. It is used today on any
embryos—known mutations not necessary.
3. Countries vary in the extent of their regulation of ARTs.
23.2 Infertility and Subfertility
1. Infertility is the inability to conceive a child after one year of trying. It affects 15% of
couples.
2. Subfertility describes couples that can conceive unaided, but require a longer time.
3. Fertility declines in females with age. In men age is associated with increased risk of
children having autism or schizophrenia.
4. Males and females contribute equally to infertility. Two factors are at play for 25% of
couples experiencing infertility.
Copyright 2021 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw Hill LLC.
,Male Infertility
1. Male infertility affects about 4% of men and may be due to low sperm count,
immobile sperm, or abnormally formed sperm.
2. About a third of male infertility cases are due to Y chromosome deletions of genes
involved in spermatogenesis.
Female Infertility
1. Female infertility can be due to an irregular menstrual cycle, blocked uterine tubes,
or reduced ovarian reserve (too few oocytes).
2. Fibroid tumors, endometriosis, or a misshapen uterus may prevent implantation of a
fertilized ovum. Secretions in the vagina and cervix may inactivate or immobilize
sperm.
3. Oocytes may not release sperm-attracting biochemicals.
4. Misaligned spindle fibers during the second meiotic division, which occurs just after
fertilization, may account for the association of infertility with maternal age.
Infertility Tests
1. Medical tests to identify the cause of infertility are conducted on the male first.
2. Sperm are checked for number, motility, and morphology.
3. Genetic analysis of the Y chromosome may reveal deletions.
4. If the male is fertile, a gynecologist will examine the structures of the woman’s
reproductive system and assess female infertility.
23.3 Assisted Reproductive Technologies
Donated Sperm—Intrauterine Insemination
1. In intrauterine insemination, donor sperm are placed into a woman’s reproductive
tract.
2. Legislation has been passed to prevent “fertility fraud”—sperm from one donor being
used to inseminate many women.
3. Excessive use of samples from the same sperm donor can result in inadvertent
consanguinity when people have children together and are closely related but do not
know it.
A Donated Uterus—Surrogate Motherhood
1. A genetic and gestational surrogate mother receives sperm using IUI and provides
her uterus for 9 months.
2. A gestational surrogate carries an embryo conceived in vitro with gametes from the
genetic parents.
In Vitro Fertilization
1. In in vitro fertilization (IVF), a sperm and an oocyte join in glassware and an early
embryo (typically a blastocyst) is transferred to the uterus.
2. A couple might choose IVF if the woman’s uterine tubes are blocked. Donor sperm
may be used in IVF if the man is infertile.
Copyright 2021 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw Hill LLC.
, 3. Intracytoplasmic sperm injection (ICSI) places immobile sperm into an oocyte.
4. Preimplantation embryos can be frozen for later use.
5. A number of factors influence success rates for IVF. These can be used to predict
the chances that the procedure will produce a live birth.
Gamete and Zygote Intrafallopian Transfer
1. In gamete intrafallopian transfer (GIFT), sperm and oocytes are placed together in
a uterine tube past a blockage.
2. In zygote intrafallopian transfer (ZIFT), a preimplantation embryo conceived in
vitro is placed in a uterine tube.
Oocyte Banking and Donation
1. Oocytes are frozen in liquid nitrogen at metaphase of meiosis 2.
2. Women may freeze oocytes to prevent the cells from being exposed to and damaged
by cancer treatments, toxins, and teratogens; to delay parenthood; because her
ovaries are damaged or must be removed; because viable sperm weren’t obtained in
time for a scheduled IVF.
3. Oocytes are first treated with cryoprotectants to prevent ice crystal damage, and
slowly rehydrated when needed. Alternatively, ovarian tissue can be frozen and
implanted under the skin or near an ovary.
4. Some women who have IVF donate extra oocytes. In embryo adoption, an oocyte
donor undergoes IUI and a preimplantation embryo is washed out of her uterus and
transferred to the gestational mother.
5. Cytoplasmic donation injects cytoplasm of oocytes from younger women into the
oocytes of older women.
Preimplantation Genetic Diagnosis
1. In PGD, a cell is removed from an 8-celled embryo and screened for genetic and
chromosomal abnormalities, or have the exome or genome sequenced, then
transferred to the uterus if no abnormalities are detected. Typically the embryo divides
in vitro until the blastocyst stage and is then transferred to the woman’s body.
2. PGD is diagnostic if it detects a mutation known to be in sperm or oocyte donor, but a
“screen” if it does not look for specific mutations and is instead used to select an
embryo with the best chance of developing into a healthy newborn.
3. PGD to select trivial traits, such as sex, is controversial.
Sequential Polar Body Analysis
1. Sequential polar body analysis tests a second polar body to see if it does not have
a specific mutation that the woman carries, to infer that the fertilized ovum also does
not have the mutation.
2. PGD is used to confirm the results of sequential polar body analysis, which is still
experimental.
23.4 Extra Embryos
1. Extra oocytes, fertilized ova, and embryos from IVF are stored indefinitely,
donated, discarded, or used in research.
Copyright 2021 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw Hill LLC.
Genetics 13th Editon By Ricki
Lewis (All Chapters 1-23,
100% Original Verified, A+
Grade)
All Chapters Arranged
Reverse: 23-1
Part 1: Instructor Manual
Part 2: Answers to selected
Key Concepts Questions
,Part 1: Instructor Manual: Chapter 23-1
Chapter 23 Reproductive Technologies
READINGS
Chapter Opener
Choosing an Embryo
Clinical Connection 23.1
The Case of the Round-Headed Sperm
Bioethics
Removing and Using Gametes After Death
CHAPTER OVERVIEW
Assisted reproductive technologies (ARTs) provide ways for people to
have children who have infertility. Countries vary in the extent of their
regulation of ARTs. In vitro fertilization (IVF) teamed with
preimplantation genetic diagnosis (PGD) screens early embryos for
specific mutations and/or chromosomal abnormalities. Selected
embryos are transferred to the uterus to complete development.
Sequential polar body analysis detects mutations in polar bodies and
uses Mendel’s first law to infer the genotype of the associated oocyte.
ARTs present ethical dilemmas and legal considerations concerning
parental identity. Extra oocytes, fertilized ova, and embryos from ARTs
can be stored indefinitely, donated, discarded, or used in research.
CHAPTER OUTLINE
23.1 Savior Siblings and More
1. Assisted reproductive technologies (ARTs) replace gametes, aid fertilization, or
provide a uterus, to help people with infertility.
2. Preimplantation genetic diagnosis (PGD) was developed to allow families with
known single-gene diseases or chromosomal anomalies to select embryos that do
not have the mutation for transfer to the woman’s uterus. It is used today on any
embryos—known mutations not necessary.
3. Countries vary in the extent of their regulation of ARTs.
23.2 Infertility and Subfertility
1. Infertility is the inability to conceive a child after one year of trying. It affects 15% of
couples.
2. Subfertility describes couples that can conceive unaided, but require a longer time.
3. Fertility declines in females with age. In men age is associated with increased risk of
children having autism or schizophrenia.
4. Males and females contribute equally to infertility. Two factors are at play for 25% of
couples experiencing infertility.
Copyright 2021 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw Hill LLC.
,Male Infertility
1. Male infertility affects about 4% of men and may be due to low sperm count,
immobile sperm, or abnormally formed sperm.
2. About a third of male infertility cases are due to Y chromosome deletions of genes
involved in spermatogenesis.
Female Infertility
1. Female infertility can be due to an irregular menstrual cycle, blocked uterine tubes,
or reduced ovarian reserve (too few oocytes).
2. Fibroid tumors, endometriosis, or a misshapen uterus may prevent implantation of a
fertilized ovum. Secretions in the vagina and cervix may inactivate or immobilize
sperm.
3. Oocytes may not release sperm-attracting biochemicals.
4. Misaligned spindle fibers during the second meiotic division, which occurs just after
fertilization, may account for the association of infertility with maternal age.
Infertility Tests
1. Medical tests to identify the cause of infertility are conducted on the male first.
2. Sperm are checked for number, motility, and morphology.
3. Genetic analysis of the Y chromosome may reveal deletions.
4. If the male is fertile, a gynecologist will examine the structures of the woman’s
reproductive system and assess female infertility.
23.3 Assisted Reproductive Technologies
Donated Sperm—Intrauterine Insemination
1. In intrauterine insemination, donor sperm are placed into a woman’s reproductive
tract.
2. Legislation has been passed to prevent “fertility fraud”—sperm from one donor being
used to inseminate many women.
3. Excessive use of samples from the same sperm donor can result in inadvertent
consanguinity when people have children together and are closely related but do not
know it.
A Donated Uterus—Surrogate Motherhood
1. A genetic and gestational surrogate mother receives sperm using IUI and provides
her uterus for 9 months.
2. A gestational surrogate carries an embryo conceived in vitro with gametes from the
genetic parents.
In Vitro Fertilization
1. In in vitro fertilization (IVF), a sperm and an oocyte join in glassware and an early
embryo (typically a blastocyst) is transferred to the uterus.
2. A couple might choose IVF if the woman’s uterine tubes are blocked. Donor sperm
may be used in IVF if the man is infertile.
Copyright 2021 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw Hill LLC.
, 3. Intracytoplasmic sperm injection (ICSI) places immobile sperm into an oocyte.
4. Preimplantation embryos can be frozen for later use.
5. A number of factors influence success rates for IVF. These can be used to predict
the chances that the procedure will produce a live birth.
Gamete and Zygote Intrafallopian Transfer
1. In gamete intrafallopian transfer (GIFT), sperm and oocytes are placed together in
a uterine tube past a blockage.
2. In zygote intrafallopian transfer (ZIFT), a preimplantation embryo conceived in
vitro is placed in a uterine tube.
Oocyte Banking and Donation
1. Oocytes are frozen in liquid nitrogen at metaphase of meiosis 2.
2. Women may freeze oocytes to prevent the cells from being exposed to and damaged
by cancer treatments, toxins, and teratogens; to delay parenthood; because her
ovaries are damaged or must be removed; because viable sperm weren’t obtained in
time for a scheduled IVF.
3. Oocytes are first treated with cryoprotectants to prevent ice crystal damage, and
slowly rehydrated when needed. Alternatively, ovarian tissue can be frozen and
implanted under the skin or near an ovary.
4. Some women who have IVF donate extra oocytes. In embryo adoption, an oocyte
donor undergoes IUI and a preimplantation embryo is washed out of her uterus and
transferred to the gestational mother.
5. Cytoplasmic donation injects cytoplasm of oocytes from younger women into the
oocytes of older women.
Preimplantation Genetic Diagnosis
1. In PGD, a cell is removed from an 8-celled embryo and screened for genetic and
chromosomal abnormalities, or have the exome or genome sequenced, then
transferred to the uterus if no abnormalities are detected. Typically the embryo divides
in vitro until the blastocyst stage and is then transferred to the woman’s body.
2. PGD is diagnostic if it detects a mutation known to be in sperm or oocyte donor, but a
“screen” if it does not look for specific mutations and is instead used to select an
embryo with the best chance of developing into a healthy newborn.
3. PGD to select trivial traits, such as sex, is controversial.
Sequential Polar Body Analysis
1. Sequential polar body analysis tests a second polar body to see if it does not have
a specific mutation that the woman carries, to infer that the fertilized ovum also does
not have the mutation.
2. PGD is used to confirm the results of sequential polar body analysis, which is still
experimental.
23.4 Extra Embryos
1. Extra oocytes, fertilized ova, and embryos from IVF are stored indefinitely,
donated, discarded, or used in research.
Copyright 2021 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the
prior written consent of McGraw Hill LLC.
