Biological Beginnings Flashcards
natural selection
evolutionary process by which those individuals of a species that are best adapted are the ones that survive and reproduce
Darwin
On the Origin of Species, adaptation to survive & pass on genes
adaptive behavior
behavior that promotes an organism’s survival in the natural habitat
evolutionary psychology
emphasizes importance of adaptation, reproduction, and “survival of the fittest” in shaping behavior
Buss
evolution pervasively influences our aggression, fears, and mating habits
extended childhood of humans
to develop large brain and experiences necessary to become competent adults before reproducing
Baltes
benefits conferred by evolutionary selection decrease with age, thereby making old age filled w/diseases & disorders like Alzheimer’s that would have been weeded out through natural selection if it affected more 20 year-olds
bidirectional evolutionary view
just as our environment shapes us, we shape our environments, cyclical
chromosomes
nucleus of human cells, threadlike DNA structures
DNA
complex molecule w/ double helix shape (like a spiral staircase) that carry genetic info
Gene
units of hereditary info, short segments of DNA, humans have about 20,500 genes that collaborate with each other and with nongenetic factors inside & outside the body
mitosis
cell reproduction wherein nucleus duplicates itself and then cell divides, each w/ 23 pairs of chromosomes
meiosis
person reproduction where cell of the testes or ovaries duplicates its chromosomes but then divides twice, forming 4 cells with half the genetic material each so that each egg or sperm has 23 unpaired chromosomes
fertilization
egg & sperm fuse to create a single cell, called a zygote
X & Y chromosomes
females-23rd pair is XX
males-23rd pair is XY
genetic variability
combining genes of 2 parents is valuable b/c there are more characteristics for natural selection to operate on
genotype
all of a person’s genetic material
phenotype
observable characteristics, expressed genetic material
dominant vs. recessive genes
dominant-the gene that exerts its effects
recessive-the gene that is overridden by the dominant one, only being expressed if both genes in the pair are recessive
X-linked inheritance
when a mutated gene is carried on the X chromosome
In males (who have no “back-up” X) it will express itself.
In females it will usually be overridden.
genetic imprinting
the expression of a gene has different effects depending on whether the mother or the father passed it on
polygenic inheritance
the interaction of many different genes that affect a characteristic
chromosomal abnormalities
lack of appropriate number of chromosomes
Down syndrome, Klinefelter syndrome, Fragile X syndrome, Turner syndrome, XYY syndrome
gene-linked abnormalities
presence of harmful genes
Phenylketonuria (PKU), Sickle-cell anemia
ultrasound sonography
prenatal medical procedure in which high-frequency sound waves are directed into the pregnant woman’s abdomen, no risk, detects structural abnormalities
fetal MRI
magnetic resonance imaging uses a magnet and radio images to generate detailed images of the body’s organs and structures
chorionic villus sampling
prenatal medical procedure in which a small sample of the placenta is removed
amniocentesis
prenatal medical procedure in which a sample of amniotic fluid is withdrawn by syringe and tested for chromosomal or metabolic disorders
triple screen
maternal blood test to determine elevated risk for birth defects
noninvasive prenatal diagnosis
isolating and examining fetal cells circulating in the mother’s blood and analyzing cell-free fetal DNA in maternal plasma
infertility
approx. 10-15% of couples in the US struggle; more than 2 million couples seek help for infertility yearly
adoption
children adopted very early in life have better outcomes than those adopted as older children
behavior genetics
field that seeks to discover the influence of heredity and environment on individual differences in human traits and development
twin study
behavioral similarity of identical twins is compared with the behavioral similarity of fraternal twins
adoption study
investigators seek to discover whether behavior and psychological characteristics of adopted children are more like those of their adoptive parents or their biological parents
heredity-environment correlations
individuals’ genes may influence the types of environments to which they are exposed
passive genotype-environment correlations
biological parents, who are genetically related to the child, also provide the rearing environment
evocative genotype-environment correlations
a child’s characteristics elicit certain types of environments
active (niche-picking) genotype-environment correlations
children seek out environments they find compatible and stimulating
shared environmental experiences
siblings’ common experiences
nonshared environmental experiences
a child’s unique experiences, both with the family and outside the family
epigenetic view
development is the result of an ongoing, bidirectional interchange between heredity and the environment
G X E interaction
gene X environment interaction
the interaction of a specific measured variation in the DNA and a specific measured aspect of the environment
pharmacogenetics
study of gene-environment interaction involving the individual’s genotype and drug treatment
