Chapter 2 (Heredity, Prenatal Development, Birth) Flashcards
(20 cards)
environmental dangers on a fetus
teratogens
genes
sequences of nucleotides that make up protein.
Difference between mitosis and meiosis
Mitosis occurs in body cells. All the chromosomes are copied once, divide once, and the cell splits once, which results in two identical cells with 23 pairs, or 46 chromosomes. Meiosis occurs in the gametes (sperm and egg), the chromosomes exchange genes (crossing over), are copied once, and then divide twice to form 4 cells with 23 chromosomes. In body cells, 22 of the 23 pairs of chromosomes are autosomes. The other pair, the sex chromosomes, are XX for genetic female and XY for genetic male.
genotype vs phenotype
genotype is the total of all the genes someone has. phenotype refers to the features that are expressed.
homozygous vs heterozygous
Homozygous means we inherited the same version of a gene from both the mother and the father, and we will express the trait. Heterozygous means we inherit different versions of a gene from the mother and the father, and we may or may not express the trait.
dominant vs recessive
Dominant (are expressed in a phenotype even when paired with a different version of the gene)
Recessive (are expressed in a phenotype only when paired with a similar recessive gene)
different versions of a gene, determine phenotype, but not genotype
Allele
when a trait is the result of multiple genes
polygenic
Incomplete dominance
when the dominant does not fully suppress the recessive gene (example: sickle cell anemia, which is expressed with two recessive genes. A carrier, someone with only one recessive gene, does not have sickle cell anemia but may experience symptoms when they have oxygen deprivation.)
Twins
- *Monozygotic twins - identical twins, when a fertilized egg splits in the first two weeks of development. Genetically identical - same genotype, usually the same phenotype. (1/3 of all twins are identical)
- *Dizygotic twins - fraternal twins, when two separate eggs are fertilized by two separate sperm. Share the same amount of genetic similarity as any siblings (genetically and phenotypically different). Older mothers and those who use fertility drugs are more likely to have dizygotic twins.
Define behavioral genetics
Behavioral genetics study the interplay between environmental influences and genetic influences on behavior. Interplay: the environment affects the expression of genes, and someone’s genetic predisposition affects their potential. Environmental factors can trigger symptoms of genetic disorders. For example, people who are predisposed to sickle cell anemia can experience symptoms under oxygen deprivation, and type two diabetes with poor diet and exercise.
Define epigenetic
the studying the relationship between DNA and gene expression (changes in phenotypes without a change in genotypes). Environmental factors can switch genes on and off (nutrition, stress, teratogens), and then the changes continue when the cells divide. Ex. monozygotic twins are similar in their early years, but over time their gene expression changes due to differences in environment/experience. (personality/disease)
the layer of cells on the surface of the brain
neocortex
pelvic inflammatory disease (PID)
an infection of a woman’s reproductive organs, common cause of infertility. STDs and non-sexually transmitted infections can cause PID.
In vitro fertilization
(IVF) eggs are taken from a female, fertilized outside of the woman’s body, and inserted into the uterus.
also:
-GIFT, gamete intra-fallopian tube transfer: insert both sperm and egg into the fallopian tube and fertilization happens naturally
-ZIFT, zygote intra-fallopian tube transfer: sperm and egg are fertilized outside the woman’s body, then inserted into the fallopian tube. Higher success rates than GIFT or IVF.
Describe how expectant parents prepare for childbirth
Lamaze method:
teaching the woman to be in control through muscle relaxation, breathing, having a focal point/picture to look at, and having a support person during training and delivery.
Explain why a caesarean or induced birth is necessary
health problems in the mother, baby shows distress, vagina is not big enough, more than one baby, and position of the baby (ex. breech, head is not downward)
Describe the two common procedures to assess the condition of the newborn
APGAR - appearance, pulse, grimace, activity, respiration. score of 5 or less is concerning. Babinsky reflex is tested (stroke the bottom of the foot, the toes should fan).
NBAS - Neonatal Behavioral Assessment Scale. analyzes motor development, muscle tone, and stress response. Especially used with children with low APGAR scores.
Postpartum Maternal Concerns
baby blues - sadness 3-5 days after having a baby, usually gone 10 days after birth. Trouble sleeping and moodiness.
Postpartum depression - during pregnancy or in 4 weeks after pregnancy, partly due to change in hormones. Sadness, sleepiness, difficulty bonding. Mood/psychotic features can appear, especially if present before pregnancy.
Postpartum anxiety - oxytocin which aids bonding also raises anxiety to help protect the child.
Describe the function of genetic counseling and why individuals may seek genetic counseling
Genetic counseling tests for and explains potential genetic conditions in people and/or their offspring.
People may do this if:
-their family or ethnic group has a history of a genetic condition.
-to get further information like blood tests, amniocentesis, or ultra sounds
-to learn the chances of having a baby with a genetic condition if they have risk factors, ex. are older, had several miscarriages, have children with birth defects, experience infertility, and/or have a medical condition.
