Chapter 2, Conception, Heredity Flashcards
Polygenic
human features as a result of many genes
Multifactorial:
human features are a result of many factors, both genetic and environmental
Epigenetic Framework:
bidirectional interplay between nature and nurture; suggests that environment can affect the expression of genes just as genetic predispositions can impact a person’s potentials
Passive Genotype Environment Correlation:
occurs when children passively inherit genes and the environments their families naturally provide (for example, athleticism: inherited genes that are already healthy, plus being raised in an environment where working out/sports is commonplace) climbers
Evocative Genotype Environment Correlation:
refers to how the social environment reacts to individuals based on their inherited characteristics (EXAMPLE: whether someone is shy or outgoing affects how others treat them: THEY EVOKE THIS RESPONSE FROM THE ENVIRONMENT), social anxiety
Active Genotype Environment Correlation:
occurs when individuals seek out environments that support their genetic tendencies “NICHE PICKING” (EXAMPLE: children who are naturally musically inclined seek out music instruction)
Adoption studies and likelihood of developing psychopathology
RESULTS 1: children whose biological parents exhibited psychopathology exhibited fewer behavioral problems when their adoptive parents used more structured parenting than unstructured
RESULTS 2: elevated psychopathology in adoptive parents increased the risk for the children’s development of behavioral problems BUT ONLY WHEN THE BIOLOGICAL PARENTS’ PSYCHOPATHOLOGY WAS HIGH
CONCLUSION: results show how environmental effects on behaviur differ BASED ON GENOTYPE, especially stressful environments combined with generally at-risk children
Genes:
recipes for making proteins, while proteins influence the structure and functions of cells; located on the chromosome
Mitosis:
cell’s nucleus making an exact copy of all the chromosomes and splitting into two new cells; MOST CELLS OF THE BODY ARE MADE THIS WAY AFTER CONCEPTION
Meoisis:
forms the cells used in sexual production like sperm or ova (gametes); the gamete’s chromsomes duplicate and then divide twice resulting in four cells containing only half the genetic material of the original gamete (THUS EACH SPERM AND EGG POSSESSES ONLY 23 CHROMOSOMES AND COMBINES TO PRODUCE THE NORMAL 46)
Autosomes:
of the 23 pairs of chromosomes created at conception, 22 pairs are at similar length
Sex Chromosomes:
differ in length; XY male XX female
Homozygous vs heterozygous/ allelles
Homozygous: when both genes inherited from the mother and father (both pairs) are the same = WE WILL DISPLAY THAT CHARACTERISTIC
If we receive a different version of the gene from each parent: HETEROZYGOUS, THE DOMINANT ONE WILL WIN
Recessive genes can only express themselves when paired with a similar version gene (alleles)
Huntington’s Disease;
Most genetic disorders are linked to the dominant gene, but most of these are not serious
dominant gene linked disorder that affects the nervous system and is fatal, but does not appear until midlife
Why are recessive gene disorders more likely to be fatal?
Recessive gene disorders: cystic fibrosis and sickle-cell anemia, less common but more fatal because they are less likely to be detected
Why are men at greater risk for sex-linked disorders and in what situation are females equally at risk?
Men are at greater risk for sex-linked disorders due to a recessive gene such as hemophilia, color blindness, and baldness
For females to be affected by recessive genetic defects, they need to inherit the recessive gene on BOTH X CHROMOSOMES
^^IF THE DEFECTIVE GENE IS DOMINANT, FEMALES ARE EQUALLY AT RISK THOUGH
Put all genetic disorders in flashcards?
Chromosomal Abnormality and causes
occurs when a child inherits too many or too few chromosomes: MOST COMMON CAUSE IS THE AGE OF THE MOTHER; as the mother ages, the ovum is more likely to suffer abnormalities due to longer term exposure to environmental factors
Sex Linked Chromosomal Disorders
When an abnormality occurs on the 23rd pair; when person has more or less than two sex chromosomes
Zygote vs blastocyte
Zygote: cell containing the combined genetic info from both parents
Blastocyte: after 5 days of mitosis, 100 cells
Why is mitosis fragile?
Mitosis is fragile and fewer than one half of all zygotes survive beyond the first two weeks; egg and sperm didnt join properly, too little or damaged genetic material, zygote doesn’t replicate, blastocyte doesn’t implant into uterine wall
When does the embryonic period start and what kind of developments begin?
Embryo, Week 3 Gestational Age (5 Weeks Maternal)
Basically a worm like tube
Starting 3rd week, the blastocyst has implanted into the uterine wall
Placenta separates baby’s blood from mother’s; acts as a filter, nourishes fetus
Placenta takes urine from fetus out and filters out hazardous chemicals
Our common ancestor is a fish= why we have tails/gills
Cephalocaudal Development: head to tail development, structures nearest head develop first
Proximodistal Development: midline outward, structures nearest torso develop first
When does the fetal organism begin responding to touch?
20% of organisms fail during the embryonic period, approximately 1 inch and can respond to touch
