DevPsy M2

• Fertilization


  Union of sperm and ovum to create a zygote
• Zygote


  One-celled organism resulting from fertilization, first form of a baby, also called "fertilized egg"
• Fertile Window


  The time during which conception is possible, highly unpredictable, we can conceive at any time of the month, it's just that there are higher likelihoods at certain times
• Menstruation


  Composed of blood, vaginal secretions, sheddings of endometrium (uterus lining), and the unfertilized egg, least fertile since ovum dies, but still possible if the sperm cells survive until ovulation
• Sperm


  Male gametes or sex cells, produced in the testicles (testes) or reproductive glands of a mature male at a rate of several hundred million a day and are ejaculated in the semen at sexual climax, long tail for mobility, rounded head to release enzymes to penetrate the ovum's thick surface
• Ovum


  Female gametes or sex cells, also called "egg cells", released by one of the ovaries (alternate yung ovary each month), at birth, a girl has 2 million immature ova (females are born with all the eggs that they'll ever have)
• Process of Fertilization

  1. Vagina - sperm cells go in first

  2. Acidity - some die due to the acidic environment

  3. Cervix - they pass through the cervix (opening of the uterus), normally closed, but during ovulation, it opens for the sperm to go in

  4. Uterus - immune system produces sticky substances since it thinks the sperm cells are invaders, some get trapped

  5. Fallopian tubes - as they pass through the uterus, they encounter the left and right fallopian tubes, some go to the empty tube, and some go to the tube with the released ovum

  6. Hyperactive - head of sperm cells alter and they become hyperactive due to the chemicals in that tract

  7. Cilia - some get trapped by the cilia or hair cells in the fallopian tube

  8. Outermost layer of the egg - once they get near, they squeeze in their body through the outermost layer of the egg

  9. Enzymes - they release enzymes to penetrate the thick surface of the egg

  10. Zygote - they race to touch the innermost layer of the egg to fertilize it and create a zygote, when a sperm cell gets absorbed by that layer, no one can move or enter anymore
• Multiple Births


  Twins, triplets, quadruplets, etc.
• Dizygotic Twins


  More common, result of 2 separate eggs being fertilized by 2 different sperm to form 2 unique individuals, has 2 separate Placenta (organ in the womb that provides nutrients), tend to run in families, can skip generations due to the mother having only sons, share 50% of their genes; like normal siblings
• Monozygotic Twins


  Result from cleaving of 1 fertilized egg, generally genetically identical, can still differ outwardly since people are the result of interaction between genes and environmental influences, shared placenta
• Twin-to-Twin Transfusion Syndrome (TTTS)


  A condition that only affects monozygotic twins, blood vessels of the placenta form abnormally, placenta is shared unequally between the twins, so 1 twin receives a smaller share of nutrients than the other, that twin can die then the other twin will either suffer severe brain damage or die as well, if both twins survive, 1 twin will be significantly larger than the other
• Factors in the rise of multiple births

  • The trend toward delayed childbearing
  • The increased use of fertility drugs and of assisted reproductive techniques such as In Vitro Fertilization (fertilization that occurs outside the body)
• Risks of higher multiple births

  • Pregnancy complications
  • Premature delivery
  • Low birth-weight infants
  • Disability or death of the infant
• Heredity


  Study of the genetic transmission of heritable characteristics from parents to offspring
• Deoxyribonucleic Acid (DNA)


  Double-helix structure that resembles a long, spiraling ladder whose steps are made of pairs of chemical units called bases
• Bases


  Adenine (A), Thymine (T), Cytosine (C), and Guanine (G), the letters of the genetic code that cellular machinery reads, sequence of bases in a gene tells the cell how to make the proteins that enable it to carry out specific functions
• Chromosomes


  Coils of DNA that consist of smaller segments called genes, every cell in the normal human body (aside from the sex cells) contain 23 pairs of chromosomes---46 in all

  
• Genes


  The functional units of heredity, each gene is located in a definite position on its chromosome and contains thousands of bases

  
• Human Genome


  Complete sequence of genes in the human body, every human has a unique genome
• What determines sex

  • Autosomes - Chromosomes that are not related to sexual expression, the first 22 pairs
  • Sex Chromosomes - Chromosomes that govern the baby's sex, the last pair of chromosomes (23rd) that determines a human's sex, every ovum has an X chromosome, but the sperm may contain either an X or a Y chromosome, XX pair makes a female baby while XY pair makes a male baby
  • SRY Gene - The gene for maleness, found in the Y chromosome, provides instructions for making a protein called the sex-determining region Y protein, it triggers cell differentiation and formation of the testes, without this, a genetically male mouse will develop genitals that appear female rather than male

  
• Alleles


  Genes that can produce alternative expressions of a characteristic (such as the presence or absence of dimples)
• Homozygous


  When a person has two identical alleles for a trait
• Heterozygous


  When a person has different alleles for a trait
• Dominant Inheritance


  An allele that is always expressed or shows up as a trait in a person, the person will look the same whether or not he or she is heterozygous or homozygous because the recessive allele doesn't show
• Recessive Inheritance


  For the trait to be expressed, the person must have two recessive alleles, if a recessive trait is expressed, that person cannot have a dominant allele
• Polygenetic Inheritance


  Traits that are controlled by multiple genes and/or influenced by the environment, although single genes often determine abnormal traits, there is no single gene that accounts for individual differences in any complex normal behavior
• Genotype


  Underlying genetic makeup, recipe for making a person
• Phenotype


  The observable characteristics, how a person actually turns out
• Multifactorial Transmission


  Combination of genetic and environmental factors to produce certain complex traits, illustrates the action of nature and nurture influences and how they mutually and reciprocally affect outcomes, experience modifies the expression of the genotype for most traits

  
• Epigenesis


  Chemical molecules (or "tags") attached to a gene that alters the way a cell "reads" the gene's DNA, genes are turned off or on as they are needed by the developing body or when triggered by the environment, epigenetic changes can occur throughout life in response to environmental factors such as nutrition, smoking, sleep habits, stress, and physical activity, environmental influences can also be social in nature
• Genetic Imprinting


  For most genes, we inherit two working copies – one from mom and one from dad. But with imprinted genes, we inherit only one working copy, genetic information inherited from the parent of one sex is activated, but genetic information from the other parent is suppressed, when a normal pattern of imprinting is disrupted, abnormal fetal growth or congenital growth disorders may result
• Prader-Willi syndrome


  A rare genetic condition that affects a child's metabolism, it can also affect your child's body and behavior, this happens when dad's copy is missing or when there are two maternal copies
• Angelman syndrome


  A rare and complex neuro-developmental condition that causes developmental delays, intellectual disabilities, speech impairments and movement issues, this happens when mom's copy is missing or when there are two paternal copies
• Phenotypes for most normal traits, such as intelligence and personality, are subject to a complex array of [BOTH] hereditary and environmental forces.
• Behavioral Genetics


  Its goal is to measure how much heredity and environment influence particular traits
• Heritability


  Developed by behavioral geneticists as a means of estimating how much of a trait is due to genetics and how much is the result of environmental influences, expressed as a percentage ranging from 0.0 to 1.0: the higher the number, the greater the heritability of a trait

  
• Reaction range


  Refers to a range of potential expressions of a hereditary trait, some inherited traits have a wider range of possible variances in how they show in the phenotype
• Canalization


  Limitation on variance of expression of certain inherited characteristics, some traits or characteristics have a strong, built-in tendency to develop in a certain way despite changes in the environment, highly canalized traits are too important to be left to chance, they have to be predictable and reliable for survival
• Genotype-Environment Interaction


  Refers to the effects of similar environmental conditions on genetically different individuals and vice versa
• Genotype-Environment Correlation (Covariance)


  Genes influence a person's exposure to particular environments, the environment often reinforces genetic differences, includes passive correlation, reactive/evocative correlation, and active correlation (niche-picking)