Chapter 2 Flashcards
Sex Cells
Gametes: the sex cells, also called sperm and ova; these contain only half as many chromosomes (haploid cell) as a regular cell (diploid cell)
Gametes are created through Meiosis
When the egg and sperm meet during conception, a Zygote is created, it again has 46 cells
Cooley’s Anemia
Recessive
Pale appearance, delayed physical growth, lethargy in infancy
Cystic Fibrosis
Recessive
Lungs, liver, and pancreas secrete large amounts of mucous, problems with breathing and digestion
Phenylketonuria (PKU)
Recessive
Problems metabolizing phenylalanine which builds up and damages the central nervous system, causing mental retardation
Sickle Cell Anemia
Recessive
Red blood cells take on a sickle shape, which causes problem with oxygen traveling to parts of body, causing anemia and pain
Tay-Sachs Disease
Recesive
Central nervous system degenerates at age 6 months, child eventually deteriorates and dies
Huntington’s Disease
Dominant
Central nervous system deteriorates, leads to muscular and mental degeneration, usually in the 30s-40s.
Marfan Syndrome
Dominant
Tall, slender build, elongated limbs, may have heart defects and skeletal issues
Duchenne Muscular Dystrophy
X-Linked
Loss of muscular control between age 7-13, child dies as muscles continue to weaken
Hemophilia
X-Linked
Blood never clots normally, something as simple as a bad bruise can be a serious health risk
Diabetes Insipidus
X-Linked
Diabetes in which the child has severe problems with thirst and dehydration, can cause nervous system damage
X-Link diseases are more common in…
…males because they only have one copy of the x-chromosome
Incomplete Dominance
Both alleles are expressed at thesame time, creating a combined phenotype.
Example: Sickle Cell Anemia occurs when the child inherits two recessive genes for sickle-shaped red blood cells. They have a mix of regular and sickle cells in their blood.
Genomic Imprinting
Alleles are imprinted through a chemical process (methylation) so that one gene is activated, whether it’s dominant or recessive
Prader-Willi Syndrome: intellectual disabilities and severe obesity
Fragile X Syndrome: severe mental disabilities, ADHD, autism, & anxiety
Germline Mutation
Affects the gametes & is passed along to the children
Somatic Mutation
Normal body cells mutate at some random point in a lifetime
Down Syndrome
Child receives 3 copies of chromosome 21
The most common chromosome disorder – happens in 1 out of 700 births
Intellectual disability, memory problems, & slow motor development
Babies show the disorder with poor eye-to-eye contact, poor grasping/muscle tone, and less exploration behavior
Risk of having a child with Down’s raises sharply after 35, up to a 1 in 11 chance if baby is had at age 50 and beyond
Genetic Counseling
Parents who believe they may be a carrier for genetic disease, can assess theirgenetic risks and chances of passing it & make decisions with a genetic counselor.
Parents older than 40 are at risk of mutations that can lead to autism, schizophrenia, and bipolar disorder
Parents will undergo blood tests and genetic testing to fill in the pedigree for the diseases of interest.
Reproductive Technology
Fertility drugs, Donor insemination, in-vitro fertilization, surrogate mothers
Fertility Drugs
Drugs such as Chlomid & Femara are given to the mother to stimulate the release of eggs
Donor insemination
Injection of sperm into a woman
In-vitro Fertilization
A woman’s egg is removed and fertilized outside of her body, then implanted back into her womb.
Prenatal Diagnostic Methods
Medical procedures that permit the parents to know about genetic problems beforehand
Amniocentesis
Taking a sample of the amniotic fluid using a needle
Fetal Blood
Blood is taken from the umbilical cord – after 20 weeks
Embryofetoscopy
A scope directly views the embryo through the embryonic sac
Indirect Relationships
Interactions between two members of the family that indirectly impact the child
Coparenting
Mutually supporting parental relationship, full of warmth, that impacts the child’s healthy growth
Parents who do not coparent will undermine each other, be more critical, and respond less to the child’s needs
How do tense parental relationships affect a child’s mental health?
Children exposed to a tense parental relationship will internalize these difficulties and feel anxious or try to repair their parents’ relationship. They may also externalize and act with anger or aggression.
Grandparents can support the parental relationship or make the conflict worse
Socioeconomic Status (SES)
Combines years of education, prestige, skill needed for a job, & income.
Low SES tend to have families earlier & have different expectations for child-rearing
Low SES
Focus on external characteristics,such as obedience, politeness,cleanliness, andneatness.
Low SES parents may feeloverwhelmed due to lack ofeducation and resources. Theyhave less time to speak to theirkids.
Low SES children enter school witha smaller lexicon
High SES
Focus on internal characteristics,such as curiosity, happiness, socialmaturity, and cognitive maturity
Parents in high SES spend moretime speaking to their children andstimulating them verbally
“30million wordgap” - high SESkids have heard substantially morewords by age 4
