Chapter 2 Flashcards
Definitions
genes
specific sequence of nucleotides and are recipes for making proteins
mitosis
cells nucleus making an exact copy of all the chormosomes and splitting into 2 cells
meiosis
gametes chromosomes duplicate and then divide twice resulting in 4 cells containing only half the genetic material of the original gamete
genotype
the genetic info of all organisms
phenotype
the observable physical traits of an organism
homozygous
same version of the gene from each parent
heterozygous
different version of the gene from each parent
dominant
express themselves in the phenotype even when presented with a different version of the gene
recessive
express themselves only when paired with a similar version of the gene
incomplete dominance
dominant gene does not completely supress the recessive gene
monozygotic twin
identical
2 fertilized eggs split apart in the first 2 weeks
dizygotic twin
fraternal
2 eggs are released and fertilized by seperate sperm
dominant genetic disorder
not usually as serious and debilitating
recessive genetic disorder
less likely to be caught
sex-linked genetic disorder
defective gene is found on the x-chromosome
(males at higher risk)
trisomy 21
(down syndrome)
occurs when there are 3 rather than 2 21st chromosomes
turners syndrome
(XO)
part or all of one chromosome is lost; impacts cognitive functioning and sexual maturation of females
klinefelters syndrome
(XXY)
extra x chromosome present in the cells of a male
genotype-environmental correlations
the process by which genetic factors contribute to variations in the environment
behavioral genetics
scientific study of the interplay between genetics and environmental contributions on behavior
passive bg
passively inherit genes with environmental encouragement
evocative bg
social environment reacts to the individual based on inherent characteristics
ex. shy, outgoing
active bg
seek out environments that support genetic tendencies
ex. seeking athlectic partner for athletic kids
genotype-environment interactions
genetic susceptibility to the environment
ex. psychopathology in adopted childen
epigenetics
study modifications in DNA that affect expression and are passed on when the cell divides
the germinal period
14 days
conception to implantation of the egg in the lining of the uterus
zygote
new cell containing the combined genetic info from both parents
blastocyst
inner and outer group of cells that results from the first 5 days of mitosis
embryonic disk
the inner group
becomes the embryo
trophoblast
outer group
support system to nourish development
the embryonic period
3rd-8th week
upon implantation of the blastocyte
embryo
multicellular organism
placenta
structure connected to the uterus that provides nourishment and oxygen to the embryo
cephalocaudal development
from head to tail growth
proximodistal development
from midline outward growth
the fetal period
9th week until birth
age of viability
the first chance of survival outside the womb
roughly 24 weeks
neural plate
location of the stem cells in the embryo
neurogenesis
formation of neurons
85 billion of them
hippocampus
part of the brain responsible for learning and memory
gray matter
contains cell bodies
white matter
contain axons that form from the neural pathways
teratogens
environmental factors that can contribute to birth defects
ex. alc, mercury
neonatal abstinence syndrome
baby addicted to drug and going through withdrawl after birth
