DEVELOPMENTAL PSYCHOLOGY (CHAP 2) Flashcards
At conception, egg and sperm unite to create a new organism that
incorporates some characteristics of each parent. Each egg and sperm cell
has__________ chromosomes,
23
threadlike structures in the nucleus that contain
genetic material.
chromosomes
first 22 pairs of chromosomes
autosomes
23rd pair determines the sex of the child
sex chromosomes
egg or ovum is fertilized by a sperm carrying a Y chromosome the product is an _________
XY zygote or male
If a sperm carrying X Chromosomes reaches the ovum first, the result is an ________
XX zygote
or female
Each chromosome actually consists of one molecule of ___________ -
molecule composed of four __________ that is the biochemical basis of Heredity
deoxyribonucleic acid (DNA) nucleotide bases
four different chemical compounds:
adenine, thymine, guanine, and cytosine.
—important biological building blocks.
amino acids, proteins, and enzymes
functional units of heredity because they determine the production of chemical substances that are,
ultimately, the basis for all human characteristics and abilities
Genes
Altogether, a person’s 46 chromosomes include roughly _________genes
30,000
The complete set of genes makes up a person’s heredity and is known as the person’s
genotype
Genetic instructions, in conjunction with environmental influences, produce a ___________
Individual’s physical, behavioral, and psychological features.
phenotype
variations of genes
Genes come in different forms
alleles
The alleles in the pair of chromosomes are sometimes the same, which is known as being
homozygous
The alleles sometimes differ, which is known as being
heterozygous
Often one allele is _________, which means that its chemical instructions are followed while those of the other,___________ allele
are ignored.
dominant
recessive
referring to a gene that actively controls the expression of a trait
Dominant traits
referring to a gene that only influences the expression of a trait when paired when an identical gene
Recessive traits
Some people are affected by heredity in a special way: They have __________ that disrupt the
usual pattern of development
genetic disorders
what disorders are inherited and sometimes eggs or sperm do not include the usual 23 chromosomes but have more or fewer
chromosomes instead.
genetic disorders
a disorder in which babies are born lacking an important liver enzyme.
Phenylketonuria (PKU)
a protein found in dairy products, bread, diet soda, and fish—into amino acids that
are required for normal body functioning.
phenylalanine
Without this enzyme, phenylalanine accumulates and produces poisons that harm the nervous
system, resulting in _______________
mental retardation
a fatal disease characterized by progressive degeneration of the nervous system.
Is caused by a dominant allele found on chromosome 4. Individuals who inherit this disorder develop normally through childhood, adolescence, and young adulthood.
Huntington’s disease
have almond-shaped eyes and a fold over the eyelid. Their head, neck, and nose are usually smaller than normal.
typically have an extra 21st chromosome that is usually provided by the egg
Down syndrome
For a woman in her late 20s, the risk of giving birth to a baby with Down syndrome is about ________; for a woman in her early
40s, the risk is about ________
1 in 1,000
1 in 50
Eggs may deteriorate over time as part of aging or because an older woman has a longer history of exposure to hazards in the environment, such as ________, that may damage her eggs.
X-rays
Common Disorder Associated with Sex Chromosomes
Kleinfelter’s syndrome
XYY complement
Turner’s Syndrome
XXX syndrome
is the branch of genetics that deals with inheritance of behavioral and psychological
traits.
Behavioral genetics
When phenotypes reflect the combined activity of many separate genes, the pattern is known as
polygenic inheritance
The behavioral consequences of genetic instructions depend on the______in which
those instructions are implemented.
environment
refers to the fact that the same genotype can produce a range of phenotypes in reaction to the environment where development takes place.
Reaction range
_____________interact dynamically throughout development
Heredity and environment
_________ can influence the kind of environment to which a person is exposed
Genes
this process of deliberately seeking environments that fit one’s heredity.
Niche-picking
forces within a family that make siblings different from one another
nonshared environmental influences
It constitutes the many changes that transform the fertilized egg into a newborn human. It begins
when a sperm successfully fertilizes an egg in the process of fertilization.
Prenatal Development
begins when sperm cells burrow their way through the outer layers of an egg cell.
Fertilization
Stages or Periods of Prenatal Development:
- the period of the zygote (Germinal)
- the period of the embryo (Emrbyonic)
- the period of the fetus (Fetal)
This period begins with fertilization and ends when the zygote implants itself in the wall of the
uterus.
.Germinal Period (Weeks 1-2)
is the technical term for the fertilized egg.
Zygote
The teaspoon or so of seminal fluid produced during a fertile male’s ejaculation contains from _________sperm. Of the sperm released into the vagina, only a few hundred will actually complete the 6- or 7-inch journey to the fallopian tubes.
200
to 500 million
The next step is ___________wherein the zygote burrows into the uterine wall and establishes connections with a woman’s blood vessels.
implantation
is a small cluster of cells near the center of the zygote that will eventually develop
into a baby
germ disc
a structure through which nutrients and wastes are exchanged between the mother and the developing organism
placenta
involves mixing sperm and egg together in a petri dish and then placing several fertilized eggs in the mother’s
uterus, with the hope that they will become implanted in the uterine wall.
in vitro
fertilization
Once the zygote is completely embedded in the uterine wall, it is called
embryo
During the period of the embryo, body structures and internal organs develop. At the beginning of
this period, three layers begin to form in the embryo.
Embryonic Period (Weeks 3-8)
The _____________ becomes hair, the outer layer of skin, and the nervous system
outer layer or ectoderm
The___________ forms muscles, bones, and the circulatory system
middle layer or mesoderm
The_____________ forms the digestive system and the lungs.
inner layer or endoderm
embryo rests in a sac called ____________which is filled with amniotic fluid that cushions the embryo and maintains a constant temperature.
amnion
houses blood vessels that
join the embryo to the placenta.
umbilical cord
The head develops before the
rest of the body or from the head to the base of the
spine.
Cephalocaudal Principle
Growth of parts near the center of the body before those that are
more distant.
Proximodistal Principle
During this period, the baby-to-be becomes much larger
and its bodily systems begin to work.
Fetal Period (Weeks 9-38)
ese and other rapid changes, by 22 to 28 weeks most systems function well enough that a
fetus born at this time has a chance to survive, which is why this age range is called the
age of
viability
(one of the B vitamins) is important for the baby’s nervous system to develop properly
Folic acid
When mothers do not consume adequate amounts of folic acid, their babies are
at risk for_____________
a disorder in which the embryo’s neural tube does not close properly
during the first month of pregnancy.
spina bifida
__________ can weaken a pregnant woman’s immune system, making her more susceptible to illness
Stress
- An agent that causes abnormal prenatal development.
Teratogen
Environmental Teratogens
Lead
Mercury
PCBs
X-rays
Teratogenic Drugs
Alcohol Aspirin Caffeine Cocaine and Heroin Marijuana Nicotine
Teratogenic Diseases
AIDS
Genital Herpes
Syphilis
Rubella
BEST RECIPE for NORMAL PRENATAL DEVELOPMENT
- Prenatal Medical Care
- Adequate Nutrition
- Avoid Chronic Stress
A counselor asks about family medical history and constructs a family tree for each parent to assess
the odds that their child would inherit a disorder. If the family tree suggests that a parent is likely to
be a carrier of the disorder, blood tests can determine the parent’s genotype.
Genetic Counseling
in which sound waves are used to generate a picture of the fetus. In this procedure, a
tool about the size of a hair dryer is rubbed over the woman’s abdomen, and the image appears on
a nearby computer monitor. The pictures generated are grainy so it takes an expert’s eye to
distinguish what’s what.
Prenatal Diagnosis (Ultrasound)
uses a syringe to withdraw a sample of amniotic fluid through the mother’s abdomen. It can be
used in pregnancies where a genetic disorder because it provides a sample of fetal cells that can be
analyzed. A needle is inserted through the mother’s abdomen to obtain a sample of the amniotic
fluid that surrounds the fetus.
Prenatal Diagnosis (Amniocentesis)
fetal cells are extracted from the placenta. A procedure that can be used much earlier in pregnancy
in which a sample of tissue is obtained from part of the placenta. A small tube—typically inserted
through the vagina and into the uterus but sometimes through the abdomen—is used to collect a
small plug of cells from the placenta. This procedure can be used within 10 or 12 weeks after
conception, much earlier than amniocentesis.
Prenatal Diagnosis (Chorionic villus sampling)
Example, in fetal hypothyroidism, the fetal thyroid
gland does not produce enough hormones. This can lead to retarded physical and mental
development, but the disorder can be treated by injecting the necessary hormones directly into the
amniotic cavity, resulting in normal growth.
Administering drugs or hormones to the fetus
field of medicine concerned with treating prenatal problems before birth
Fetal Medicine
has also been used to treat a disorder affecting identical
twins in which one twin—the “donor”—pumps blood through its own and the other twin’s
circulatory system.
Fetal surgery
in which defective genes are replaced by synthetic normal genes.
Genetic engineering
is an appropriate name for childbirth, which is the most intense, prolonged physical effort that humans experience.
Labor
Soon the top of the baby’s head appears
crowning
