Chapter 3: Forming A New Life Flashcards
What is a Fertile Window?
A woman’s most fertile days
6th to the 21st days of the menstrual cycle
What is Fertilization/Conception?
The process by which sperm and ovum (male and female gametes) combine to create a single cell
What is a gamete?
Sex cells
What is a zygote?
A single cell created through fertilization or conception
What is Ovulation?
It happens when a mature follicle in either ovary ruptures and leads to the expulsion of the ovum
What is an Ovum?
An egg cell that is swept along by thee cilia through the uterus and finally, the womb.
What are sperm cells?
Cells that are produced in a males testicles at a rate of several 100,000 a day and are ejaculated in the semen at sexual climax
What is a Cervix?
It is the opening of the uterus
How do multiple births occur?
When the mother releases two eggs with a short time or when a single unfertilized ovum splits into two
When are Fraternal/Dizygotic Twins produced?
When the mother’s body releases two eggs at the same time.
When are Identical/Monozygotic twins produced?
When a single fertilized ovum splits into two
How are Triplets or Quadruplets produced?
Through either of thee two processes or a combination of both
What are Semi-Identical Twins?
They are a result of two sperm cells fusing with a single ovum. They are more genetically similar than dizygotic twins but less similar than monozygotic twins
What are the causes of the rise in Multiple Births?
Trend toward delayed childbearing
Increased use of fertility drugs
What is heredity?
Inborn factors inherited from one’s biological parents that affect development
What is a Genetic Code?
It is the basis of heredity.
What is Deoxyrionucleic Acid (DNA)?
It is a chemical which is the basis of heredity. It has a double-helix structure which resembles a long, spiraling ladder whose steps are made of bases
What are Bases?
These are pairs of chemical units which make up steps.
What are the letters of the Genetic Code which the cellular machinery “reads?”
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
What are Chromosomes?
These are coils of DNA that consist of genes. There are 23 pairs in a human body
What are Genes?
They are functional units of heredity, located in a definite position on its chromosome and contains thousands of bases
What do the Sequence of Bases do?
They tell the cell how to make the proteins that enable it to carry out specific functions
What is a Human Genome?
It is made up of a complete sequence of genes
What is Meiosis?
Type of cell division which the sex cells undergo when they are developing
What is Mitosis?
The process by which non-sex cells divide in half over and over again.
What are Autosomes?
These are chromosomes not related to sexual expression. There are 22 pairs in the body.
What are Sex Chromosomes?
23rd pair of chromosomes, one pair from the father and one pair from the mother, that govern the baby’s sex
What is the SRY Gene?
Gene for maleness
What combination of Chromosomes produce a Genetic Female?
XX or Ovum X + Sperm Y
What chromosomes produce a Genetic Male?
XY (Ovum X + Sperm Y)
What is Wnt 4?
A variant form of signaling molecules which can masculinize a genetically female fetus
Who was Gregor Mendel?
He laid the foundation and understanding of patterns of inheritance.
What are Alleles?
Genes that can produce alternative expressions of a characteristic
What does a person receive from his parents?
A pair of Alleles for a given characteristics, one from each parent
When is a person said to be homozygous for a characteristic?
When he possesses two identical alleles for a trait.
When is a person heterozygous for a characteristic?
When he possesses differing alleles for a trait
What is Dominant Inheritance?
It is a pattern of inheritance in which, when a child receives different alleles, only the dominant one is expressed.
When an offspring receives contradictory alleles for a trait, only one of them, the dominant one, will be expressed
What is Recessive Inheritance?
It is a Pattern of Inheritance in which a child receives identical recessive alleles, resulting in expression of a nondominant trait.
What is Polygenetic Inheritance?
It is a Pattern of inheritance in which multiple genes at different sites on chromosomes affect a complex trait.
What are the 23 pairs of chromosomes in a human’s body?
22 Pairs of Autosomes
1 Pair of Sex Chromosomes
What are the types of twins?
Dizygotic or Fraternal Twins
Monozygotic or Identical Twins
What are Mutations?
Permanent alterations in genes or chromosomes that may produce harmful characteristics
What is a Phenotype?
Observable characteristics of a person
What is a Genotype?
The genetic makeup of a person, containing both expressed and unexpressed characteristics
What is the Multifactorial Transmission Phenomenon?
When experience modifies the expression of the genotype
Combination of genetic and environmental factors to produce certain complex traits.
What is Epigenesis?
A mechanism which turns genes on or off and determines functions of body cells, also known as Epigenetic Framework
What is Imprinting?
It is the differential expression of certain genetic traits, depending on whether the trait has been inherited from the mother or the father.
What is Incomplete Dominance?
Pattern of inheritance in which a child receives two different alleles, resulting in partial expression of a trait.
What is Sex-Linked Inheritance?
Pattern of inheritance in which certain characteristics carried on the X chromosome inherited from the mother are transmitted differently to her male and female offspring.
When do Chromosomal Abnormalities occur?
Chromosomal Abnormalities occur because of errors in cell division, resulting in an extra or missing chromosome.
What is Downs Syndrome?
Also called trisomy-21.
Usually caused by an extra 21st chromosome or the translocation of part of the 21st chromosome onto another chromosome
What is the most common characteristic associated with Downs Syndrome?
Downward sloping skin fold at the inner corners of the eyes
Moderate to severe mental retardation
What is Genetic Counseling?
Clinical service that advises prospective parents of their probable risk of having children with hereditary defects.
What is a Karytotype?
A chart which shows chromosomes from body tissues that are analyzed and photographed, and the photographs are enlarged and arranged according to size and structure
What is Behavioral Genetics?
It is the qualitative study of relative heredity and environmental influences on behavior
What is Heritability?
A statistical estimate of the contribution heredity makes toward differences in complex traits within a given population.
Expressed as a number ranging from 0.0 to 1.0, the greater the number, the greater the heritability of a trait
What are the three types of correlational study that researchers of behavioral genetics rely on?
Family studies
Adoption studies
Twin Studies
What do behavioral genetic researchers study in Family Studies?
The degree to which biological relatives share certain traits and whether the closeness of the familial relationship is associated with the degree of similarity
What do behavioral genetic researchers study using Adoption Studies?
They look at similarities adopted children and their adoptive families and also between adopted children and their biological families.
What do behavior genetic researchers study using Twin Studies?
They compare pairs of monozygotic twins with same-sex dizygotic twins. When monozygotic twins are more concordant than dizygotic twins, we see the likely effects of heredity.
What is Range of Reaction?
A range of potential expressions of a hereditary trait.
It can be wide or narrow, depending on environmental conditions.
What is a Norm of Reaction?
Heredity does set some limit but development is so complex and the effects of the differing environments vary. Therefore, the limits are unknowable and their effects unpredictable.
What is Canalization?
The limitation on variance of expression of certain inherited characteristics.
Certain behaviors develop along genetically dug channels and it takes an extreme change in environment to alter their course.
What is Genotype-Environment Interaction?
The portion of phenotypic variation that results from the reactions of genetically different individuals to similar environmental conditions.
What is Niche-Picking?
The tendency of a person, especially after early childhood, to seek out environments compatible with his genotype.
What are Non-Shared Environmental Effects?
The unique environment in which each child grows up, consisting of distinctive influences or influences that affect one child differently than another
What characteristics are influenced by Heredity and Environment?
Physical and Physiological Traits - Obesity
Intelligence
Personality and Psychopathology - Temperament/Schizophrenia
What is Gestation?
The approximately 38-week period of development between conception and birth
The normal range of gestation is between 38-42 weeks
What are Early Signs and Symptoms of Pregnancy?
Tender, swollen breasts or nipples Fatigue Slight bleeding or cramping Food Cravings Nausea with or without vomiting Frequent urination Frequent, mild headaches Constipation Mood swings Faintness and dizziness Raised basal body temperature
What is Gestation Age?
The age of an unborn baby, usually dated from the first day of an expectant mother’s last menstrual cycle.
What are the Stages of Prenatal Development Development?
Germinal Stage
Embryonic Stage
Fetal Stage
What are the characteristics of Germinal Stage in Prenatal Development?
Rapid cell division
Blastocyst Formation
Implantation in the wall of the uterus
What is Genotype-Environment Correlation?
The tendency of certain genetic and environmental influences to reinforce each other; may be passive, reactive, (evocative), or active
Also known as Genotype-Environment Covariance
How does Genotype-Environment Correlation work to strengthen the phenotypic expression of a genotypic tendency?
Passive Correlations
Reactive/Evocative Correlations
Active Correlations
When does the Germinal Stage of Prenatal Development occur?
From Fertilization to about two weeks of gestational stage
What is a Blastocyst?
A fluid sphere which floats freely in the uterus until the 6th day after fertilization
What layers are developed from mass during the Prenatal Stage of Development?
Ectoderm Endoderm Mesoderm Amniotic Sac Placenta Umbilical Cord
What is the Endoderm?
Lower layer, digestive system, liver, pancreas, salivary glands, and respiratory system
What is the Ectoderm?
Upper layer, nails, hair, teeth, sensory organs, and nervous systems, brain, and spinal cord.
What is the Mesoderm?
Middle layer, inner layer of the skin, muscles, skeleton, excretory systems, and circulatory systems
What is an Amniotic Sac?
A fluid filled membrane that encases he embryo, protecting it, and giving it room to grow
What is the Placenta?
Allows oxygen, nourishment, and wastes to pass between the mother and the embryo
What is the Umbilical Cord?
It is a cord which connects the embryo to the placenta
What happens in the Embryonic Stage of Prenatal Development?
Rapid growth and development of major body systems and organs
Rapid growth and development of respiratory, digestive, and nervous systems
When is the Embryonic Stage of Prenatal Development?
2 to 8 weeks of gestation
What is Spontaneous Abortion or Miscarriage?
It is the expulsion from the uterus of an embryo or fetus that is unable to survive outside the womb
Studies have shown that Male babies are more likely to be stillborn
What happens during the Fetal Stage of Prenatal Development?
This is the final stage of Gestation, the fetus grows rapidly to about 20 times its previous length, and organs an body systems become more complex during this time
What is an Ultrasound?
It uses high frequency sound waves to detect the outline of the fetus.
What are Teratogens?
These are chemicals, which can produce birth defects in fetuses
What Environmental Influences or Maternal Factors can affect the development of the fetus?
Exposure to Teratogens
Nutrition and Maternal Weight
Drug Intake
What is Fetal Alcohol Syndrome?
It is a condition which is characterized by a combination of retarded growth, face and body malformations, and disorders of the central nervous systems.
What are the effects of Nicotine on a fetus?
Increased risk of miscarriage Growth retardation Sudden Infant Death Hyperkinetic Movement Neurological Problems Behavioral Problems Stillbirth Colic Small Head Circumference Cognitive Problems
What is the effect of Caffeine on infants?
Double the risk of sudden death in infancy
Increased risk of miscarriage
What are the effects of Marijuana on the infant?
Infants can develop birth defects, low birth weight, withdrawal-like symptoms at birth, increased risk of attention disorders and learning problems, affected functioning of the brain’s frontal lobe
What are the effects of Cocaine on an infant?
Increased risk of spontaneous abortion, delayed growth, premature labor, low birthweight, small head size, birth defects, and impaired neurological development
What are the effects Metamphetamines on infants?
Low birth weight
Fetal Growth restriction
What maternal illnesses can affect the development of an infant?
Acquired Immune Deficiency Syndrome
Rubella (German Measles)
Toxoplasmosis
Diabetes
What is the effect of Moderate Maternal Anxiety on a developing fetus?
There is a spur in the organization of the developing brain.
Inattentiveness, negative emotionality or behavioral disorders in early childhood
What is the effect of Unusual Maternal Stress on a developing fetus?
They may result in malformations, cleft lip, cleft palate, and heart malformations
What is the effect of Maternal Age on the developing fetus?
There is a higher chance of miscarriage or stillbirth, complications due to diabetes, high blood pressure, or severe bleeding, higher risk of premature delivery, retarded fetal growth, birth defects, and chromosomal abnormalities
What Outside Environmental Hazards affect a developing fetus?
Air pollution
Chemicals
Radiation
Extremes of heat and humidity
What can a mother do to ensure her baby is healthy prior to conception?
Undergo physical examinations
Get vaccinations for Rubella and Hepatitis B
Undergo risk screening for genetic disorders and infectious diseases
Undergo counseling
